CINXE.COM

<!doctype html> <html lang="en"> <head> <meta charset="utf-8" /> <title>Issue Archive: 1970-1979 | Scientific American</title> <link rel="canonical" href="https://www.scientificamerican.com/archive/issues/1970s/"> <meta name="theme-color" content="#fff"/> <meta name="robots" content="max-image-preview:standard"/> <link rel="image_src" src="https://www.scientificamerican.com/static/sciam-mark.jpg"> <meta property="og:url" content="https://www.scientificamerican.com/archive/issues/1970s/"/> <meta property="og:image" content="https://www.scientificamerican.com/static/sciam-mark.jpg"/> <meta name="twitter:image" content="https://www.scientificamerican.com/static/sciam-mark.jpg"/> <meta name="description" content="Browse Scientific American's archives going back to 1845"/> <meta property="og:title" content="Issue Archive: 1970-1979"/> <meta property="og:description" content="Browse Scientific American's archives going back to 1845"/> <meta property="og:site_name" content="Scientific American"/> <meta property="og:locale" content="en_US"/> <meta name="twitter:site" content="@sciam"/> <meta name="twitter:domain" content="scientificamerican.com"/> <meta name="twitter:card" content="summary_large_image"/> <meta property="og:image:alt" content="Scientific American Logo"/> <meta name="twitter:image:alt" content="Scientific American Logo"/> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <link rel="icon shortcut" href="/static/favicon.ico" /> <link rel="alternate" type="application/rss+xml" title="RSS" href="https://www.scientificamerican.com/platform/syndication/rss/" /> <script data-layer="critical">;performance.mark('app-load-start');((d,ael,dcl,unl,cxl,log,onunl)=>{log('[readyState]',d.readyState);d[ael]('readystatechange',()=>log('[readyState]',d.readyState));d[ael](dcl,()=>log(dcl));d[ael](unl,onunl);window.onload=()=>{d.removeEventListener(unl,onunl);log('windowloaded')};})(document,'addEventListener','DOMContentLoaded','beforeunload','cancelled',(...msg)=>console.log('[dev]',...msg),()=>{window[cxl]=true;log(cxl)});((l,pii) => {if (pii.some(p => l.search.includes(p+"="))) {window.initSearch = l.search;const anon = new URLSearchParams(l.search);pii.forEach(p => anon.delete(p));history.replaceState({}, "", l.pathname + "?" + anon);} })(location, ["email", "magic_link", "token", "code", "state"]);</script> <script type="module" crossorigin src="/static/bundle.e56048fc.js"></script> <link rel="modulepreload" crossorigin href="/static/chunks/preload-helper-4aa0ec7d.js"> <link rel="modulepreload" crossorigin href="/static/chunks/vendor-react-d0986667.js"> <link rel="modulepreload" crossorigin href="/static/chunks/sciam-4e39ae07.js"> <link rel="modulepreload" crossorigin href="/static/chunks/use-piano-auth-sync-4ab8630c.js"> <link rel="modulepreload" crossorigin href="/static/chunks/datalayer-043ea249.js"> <link rel="modulepreload" crossorigin href="/static/chunks/index-59e43a0d.js"> <link rel="modulepreload" crossorigin href="/static/chunks/use-chargebee-5a11288c.js"> <link rel="modulepreload" crossorigin href="/static/chunks/use-plan-7775b4f0.js"> <link rel="modulepreload" crossorigin href="/static/chunks/use-cart-0526fb1f.js"> <link rel="modulepreload" crossorigin href="/static/chunks/useOverlay-f74ac14c.js"> <link rel="stylesheet" href="/static/assets/bundle-aba65ab5.css"> <link rel="stylesheet" href="/static/assets/DefaultLayout-2955ad5f.css"> <link rel="stylesheet" href="/static/assets/issues-39da08eb.css"> <link rel="modulepreload" href="/static/issues.2c7062af.js" crossorigin fetchpriority="auto"> <link rel="preload" href="https://cdn.cookielaw.org/scripttemplates/otSDKStub.js" as="script" fetchpriority="auto"> <link rel="preload" href="https://www.googletagmanager.com/gtm.js?id=GTM-5FLM662" as="script" fetchpriority="auto"> <link rel="preload" href="https://www.scientificamerican.com/sciads/sciads.js" as="script" fetchpriority="auto"> <link rel="preload" href="https://cdn.tp.scientificamerican.com/api/tinypass.min.js" as="script" fetchpriority="low"> <link rel="preconnect" href="https://cdn.cxense.com/cx.cce.js" as="script"> </head> <body> <div id="app"><header class="headerContainer-8KxQ5" role="banner"><a href="#main" id="skipToMain" class="skiptocontent sr-only-focusable sr-only">Skip to main content</a><div class="header-1t1JE flex-aYeiI"><div class="left-ajw3c flex-aYeiI"><a href="/" aria-label="Link to homepage" class="logoLink-Wt3sq"><span class="sr-only">Scientific American</span><svg width="1em" height="1em" viewBox="0 0 120.79 128.39" fill="currentColor" role="img" aria-label="Scientific American"><path d="M7.98 58.19c2.3 0 5.24 3.18 14.53 3.18 13.66 0 21.75-8.57 21.75-17.86 0-7.86-3.73-12.94-11.43-17.23l-9.37-5.24c-4.05-2.3-7.46-5.32-7.46-9.92 0-4.92 3.73-7.7 9.69-7.7s11.35 4.21 13.02 13.26h1.98V.95h-1.83c-.16 1.43-.87 2.06-1.75 2.06-2.06 0-4.53-2.94-12.62-2.94C13.85.08 5.12 6.51 5.12 16.35c0 7.3 3.26 11.83 9.77 15.56l9.61 5.48c5.48 3.18 7.7 6.19 7.7 10.72 0 5.64-3.18 9.77-10.64 9.77-9.29 0-13.58-5.08-15.32-16.2H4.1V60.5h1.98c.16-1.67.95-2.3 1.91-2.3Zm65.97 3.26c11.11-.03 19.13-8.81 20.4-20.72l-2.22-.64c-2.54 8.26-7.22 12.46-13.97 12.46-12.23 0-16.04-14.93-16.04-27.87 0-15.56 6.11-21.28 14.13-21.28 5.72 0 11.83 5.72 14.45 16.59h2.06V.95h-1.91c-.16 1.27-.87 2.06-2.14 2.06-1.91 0-5.72-3.02-11.83-3.02-14.85 0-28.66 12.07-28.66 32.39 0 17.39 10.96 29.1 25.72 29.06Zm14.53 42.72L76.49 68.84H56.24v1.75c3.33.16 4.76.95 4.76 5.95v42c0 6.03-1.67 8.1-5.32 8.1-2.54 0-4.53-1.91-6.51-6.91L29.11 68.12h-2.7L6.35 119.89c-2.17 5.72-4.3 6.75-6.35 6.75v1.75h18.02v-1.75c-5.8-.24-8.65-2.7-5.8-10.48l2.05-5.4h17.88l3.45 8.97c2.3 5.72.64 6.91-3.73 6.91v1.75h39.62v-1.75c-4.13 0-6.27-1.19-6.27-8.02l.48-42.08 17.07 51.29h2.14l17.63-51.05v43.9c0 5.48-1.75 5.95-5.08 5.95v1.75h23.34v-1.75c-3.33 0-4.76-.48-4.76-5.95V76.54c0-5.56 1.43-5.95 4.76-5.95v-1.75h-19.85l-12.46 35.33Zm-72.88 3.1 7.56-19.85 7.63 19.85H15.6ZM120.79 2.7V.95h-23.1V2.7c3.33 0 4.84.32 4.84 5.95v44.14c0 5.48-1.51 5.95-4.84 5.95v1.75h23.1v-1.75c-3.33 0-4.76-.48-4.76-5.95V8.65c0-5.64 1.43-5.95 4.76-5.95Z"></path></svg></a></div><div class="center-oMgM8 flex-aYeiI"></div><div class="right-4LP3J flex-aYeiI"><button type="button" id="radix-:R5t:" aria-haspopup="menu" aria-expanded="false" data-state="closed" class="trigger-8ea-U" aria-label="User Menu"><div class="dropdownIconContainer-hDbEe"><svg width="1em" height="1em" viewBox="0 0 472 472" fill="currentColor" role="img" aria-label="User" class="dropdownIcon-XeKnP profileIconImg-pc8tD"><path d="M403 69a235 235 0 0 0-334 0 235 235 0 0 0 0 334 235 235 0 0 0 334 0 235 235 0 0 0 0-334ZM118 412a122 122 0 0 1 237 0 211 211 0 0 1-237 0Zm41-197a77 77 0 1 1 155 0 77 77 0 0 1-155 0Zm216 181c-14-43-48-77-91-92a101 101 0 1 0-96 0c-43 15-77 49-91 92a212 212 0 1 1 278 0Z"></path></svg><div class="dropdownIcon-XeKnP initials-z1adZ"></div></div></button></div></div></header><main class="main-gNG8x"><h1 class="issuesTitle-F-sWZ">Archive</h1><h2 class="yearSubTitle-yMM-q">1970-1979</h2><div style="border-top:2px solid #444;padding-top:1rem;border-bottom:1px solid #ccc;top:calc(var(--nav-height,0px) - 2px);background:#fff;z-index:1;width:var(--standard-width);max-width:var(--standard-max-width);margin:1rem auto"><div style="margin:0 -1rem 0.1rem"><div class="decades" style="display:flex;justify-content:space-between;overflow-y:hidden;overflow-x:auto;-webkit-overflow-scrolling:touch;overscroll-behavior:contain;gap:0.2rem;padding:0 1rem 0.5rem 1rem;scroll-padding:1rem;font-size:0.85rem;flex-flow:row-reverse"><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1840s/">1840s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1850s/">1850s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1860s/">1860s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1870s/">1870s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1880s/">1880s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1890s/">1890s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1900s/">1900s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1910s/">1910s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1920s/">1920s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1930s/">1930s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1940s/">1940s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1950s/">1950s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1960s/">1960s</a><a class="date-selector decade exact selected" style="cursor:pointer;border:1px solid #09396922;color:#093969;background-color:#3576b322;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:700;text-decoration:none" href="/archive/issues/1970s/">1970s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1980s/">1980s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1990s/">1990s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2000s/">2000s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2010s/">2010s</a><a class="date-selector decade" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2020s/">2020s</a></div><div class="years" style="display:flex;overflow-y:hidden;overflow-x:scroll;-webkit-overflow-scrolling:touch;overscroll-behavior:contain;gap:0.2rem;padding:0 1rem 0.5rem 1rem;scroll-padding:1rem;color:#777;font-size:0.85rem;flex-flow:row-reverse"><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1845/">1845</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1846/">1846</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1847/">1847</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1848/">1848</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1849/">1849</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1850/">1850</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1851/">1851</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1852/">1852</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1853/">1853</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1854/">1854</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1855/">1855</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1856/">1856</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1857/">1857</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1858/">1858</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1859/">1859</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1860/">1860</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1861/">1861</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1862/">1862</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1863/">1863</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1864/">1864</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1865/">1865</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1866/">1866</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1867/">1867</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1868/">1868</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1869/">1869</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1870/">1870</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1871/">1871</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1872/">1872</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1873/">1873</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1874/">1874</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1875/">1875</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1876/">1876</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1877/">1877</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1878/">1878</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1879/">1879</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1880/">1880</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1881/">1881</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1882/">1882</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1883/">1883</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1884/">1884</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1885/">1885</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1886/">1886</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1887/">1887</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1888/">1888</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1889/">1889</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1890/">1890</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1891/">1891</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1892/">1892</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1893/">1893</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1894/">1894</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1895/">1895</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1896/">1896</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1897/">1897</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1898/">1898</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1899/">1899</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1900/">1900</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1901/">1901</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1902/">1902</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1903/">1903</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1904/">1904</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1905/">1905</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1906/">1906</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1907/">1907</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1908/">1908</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1909/">1909</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1910/">1910</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1911/">1911</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1912/">1912</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1913/">1913</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1914/">1914</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1915/">1915</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1916/">1916</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1917/">1917</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1918/">1918</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1919/">1919</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1920/">1920</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1921/">1921</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1922/">1922</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1923/">1923</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1924/">1924</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1925/">1925</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1926/">1926</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1927/">1927</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1928/">1928</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1929/">1929</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1930/">1930</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1931/">1931</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1932/">1932</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1933/">1933</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1934/">1934</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1935/">1935</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1936/">1936</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1937/">1937</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1938/">1938</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1939/">1939</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1940/">1940</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1941/">1941</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1942/">1942</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1943/">1943</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1944/">1944</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1945/">1945</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1946/">1946</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1947/">1947</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1948/">1948</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1949/">1949</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1950/">1950</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1951/">1951</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1952/">1952</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1953/">1953</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1954/">1954</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1955/">1955</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1956/">1956</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1957/">1957</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1958/">1958</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1959/">1959</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1960/">1960</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1961/">1961</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1962/">1962</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1963/">1963</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1964/">1964</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1965/">1965</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1966/">1966</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1967/">1967</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1968/">1968</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1969/">1969</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1970/">1970</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1971/">1971</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1972/">1972</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1973/">1973</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1974/">1974</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1975/">1975</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1976/">1976</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1977/">1977</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1978/">1978</a><a class="date-selector selected" style="cursor:pointer;border:none;color:#093969;border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:600;text-decoration:none" href="/archive/issues/1979/">1979</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1980/">1980</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1981/">1981</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1982/">1982</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1983/">1983</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1984/">1984</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1985/">1985</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1986/">1986</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1987/">1987</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1988/">1988</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1989/">1989</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1990/">1990</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1991/">1991</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1992/">1992</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1993/">1993</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1994/">1994</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1995/">1995</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1996/">1996</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1997/">1997</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1998/">1998</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1999/">1999</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2000/">2000</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2001/">2001</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2002/">2002</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2003/">2003</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2004/">2004</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2005/">2005</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2006/">2006</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2007/">2007</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2008/">2008</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2009/">2009</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2010/">2010</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2011/">2011</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2012/">2012</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2013/">2013</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2014/">2014</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2015/">2015</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2016/">2016</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2017/">2017</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2018/">2018</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2019/">2019</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2020/">2020</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2021/">2021</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2022/">2022</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2023/">2023</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2024/">2024</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2025/">2025</a></div></div></div><div class="issue__list-8JHD2"><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/BD879661-F7EF-4936-8FEC7548ABBDBE30_source.jpg?w=600" alt="Scientific American Magazine Vol 241 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/BD879661-F7EF-4936-8FEC7548ABBDBE30_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/BD879661-F7EF-4936-8FEC7548ABBDBE30_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-12-01">December 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5695F82F-6A4C-4220-871F3DC6BDE977E4_source.jpg?w=600" alt="Scientific American Magazine Vol 241 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/5695F82F-6A4C-4220-871F3DC6BDE977E4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5695F82F-6A4C-4220-871F3DC6BDE977E4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-11-01">November 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/69CF0F9D-3FB5-41CA-B9F7186231446D55_source.jpg?w=600" alt="Scientific American Magazine Vol 241 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/69CF0F9D-3FB5-41CA-B9F7186231446D55_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/69CF0F9D-3FB5-41CA-B9F7186231446D55_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-10-01">October 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A60DEA28-AAC7-45E0-AF379D83B56DC639_source.jpg?w=600" alt="Scientific American Magazine Vol 241 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/A60DEA28-AAC7-45E0-AF379D83B56DC639_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A60DEA28-AAC7-45E0-AF379D83B56DC639_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-09-01">September 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/044C9C10-0CE3-4AFE-B89EAB46965F4247_source.jpg?w=600" alt="Scientific American Magazine Vol 241 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/044C9C10-0CE3-4AFE-B89EAB46965F4247_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/044C9C10-0CE3-4AFE-B89EAB46965F4247_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-08-01">August 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/722389B4-4574-44D2-ADA0F4247E281462_source.jpg?w=600" alt="Scientific American Magazine Vol 241 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/722389B4-4574-44D2-ADA0F4247E281462_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/722389B4-4574-44D2-ADA0F4247E281462_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-07-01">July 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/FF430073-5064-4096-B4A5A3665CDAFDD7_source.jpg?w=600" alt="Scientific American Magazine Vol 240 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/FF430073-5064-4096-B4A5A3665CDAFDD7_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/FF430073-5064-4096-B4A5A3665CDAFDD7_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-06-01">June 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/509BFF54-BB92-43DD-80B0BBBD5871F961_source.jpg?w=600" alt="Scientific American Magazine Vol 240 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/509BFF54-BB92-43DD-80B0BBBD5871F961_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/509BFF54-BB92-43DD-80B0BBBD5871F961_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-05-01">May 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/89918C7B-599F-4261-AB40679155C09880_source.jpg?w=600" alt="Scientific American Magazine Vol 240 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/89918C7B-599F-4261-AB40679155C09880_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/89918C7B-599F-4261-AB40679155C09880_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-04-01">April 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/80914847-72EC-486C-87E51E69301B6365_source.jpg?w=600" alt="Scientific American Magazine Vol 240 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/80914847-72EC-486C-87E51E69301B6365_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/80914847-72EC-486C-87E51E69301B6365_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-03-01">March 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/11072C04-A629-408C-B65E9F60DA8287BE_source.jpg?w=600" alt="Scientific American Magazine Vol 240 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/11072C04-A629-408C-B65E9F60DA8287BE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/11072C04-A629-408C-B65E9F60DA8287BE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-02-01">February 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1979/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B5418E39-7712-4EE1-A13BAA9071D8DA7A_source.jpg?w=600" alt="Scientific American Magazine Vol 240 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/B5418E39-7712-4EE1-A13BAA9071D8DA7A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B5418E39-7712-4EE1-A13BAA9071D8DA7A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1979-01-01">January 1979</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/30FB08EB-D23B-4D74-8E9617EA3C037415_source.jpg?w=600" alt="Scientific American Magazine Vol 239 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/30FB08EB-D23B-4D74-8E9617EA3C037415_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/30FB08EB-D23B-4D74-8E9617EA3C037415_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-12-01">December 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2778F77E-A3E3-4462-909BAE2A20176DC4_source.jpg?w=600" alt="Scientific American Magazine Vol 239 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/2778F77E-A3E3-4462-909BAE2A20176DC4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2778F77E-A3E3-4462-909BAE2A20176DC4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-11-01">November 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9430BAA1-065D-4668-95C45FF20FA79764_source.jpg?w=600" alt="Scientific American Magazine Vol 239 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/9430BAA1-065D-4668-95C45FF20FA79764_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9430BAA1-065D-4668-95C45FF20FA79764_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-10-01">October 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/67959A48-7665-48AB-81DDB7CE1BD3EC63_source.jpg?w=600" alt="Scientific American Magazine Vol 239 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/67959A48-7665-48AB-81DDB7CE1BD3EC63_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/67959A48-7665-48AB-81DDB7CE1BD3EC63_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-09-01">September 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/232B1BB6-7922-4BD7-81BB17009329ABC3_source.jpg?w=600" alt="Scientific American Magazine Vol 239 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/232B1BB6-7922-4BD7-81BB17009329ABC3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/232B1BB6-7922-4BD7-81BB17009329ABC3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-08-01">August 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DFC968BE-9D13-4887-A5CF921812780F0D_source.jpg?w=600" alt="Scientific American Magazine Vol 239 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/DFC968BE-9D13-4887-A5CF921812780F0D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DFC968BE-9D13-4887-A5CF921812780F0D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-07-01">July 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/80366D8F-5C8C-4C0A-8D6096B91F814B3B_source.jpg?w=600" alt="Scientific American Magazine Vol 238 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/80366D8F-5C8C-4C0A-8D6096B91F814B3B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/80366D8F-5C8C-4C0A-8D6096B91F814B3B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-06-01">June 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/7329B9DC-BD11-45D0-B8B2DB615655B0EA_source.jpg?w=600" alt="Scientific American Magazine Vol 238 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/7329B9DC-BD11-45D0-B8B2DB615655B0EA_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/7329B9DC-BD11-45D0-B8B2DB615655B0EA_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-05-01">May 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/BA7BD179-BB54-4441-B825CD1851ECF715_source.jpg?w=600" alt="Scientific American Magazine Vol 238 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/BA7BD179-BB54-4441-B825CD1851ECF715_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/BA7BD179-BB54-4441-B825CD1851ECF715_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-04-01">April 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/85590875-BA08-434D-B899C1EFB8BC0AC2_source.jpg?w=600" alt="Scientific American Magazine Vol 238 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/85590875-BA08-434D-B899C1EFB8BC0AC2_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/85590875-BA08-434D-B899C1EFB8BC0AC2_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-03-01">March 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/6F6B51E7-FD0F-4C41-B7F8C65C234F6531_source.jpg?w=600" alt="Scientific American Magazine Vol 238 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/6F6B51E7-FD0F-4C41-B7F8C65C234F6531_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/6F6B51E7-FD0F-4C41-B7F8C65C234F6531_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-02-01">February 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1978/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F3108CA0-4C9B-4759-81F0B800AC83F24B_source.jpg?w=600" alt="Scientific American Magazine Vol 238 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/F3108CA0-4C9B-4759-81F0B800AC83F24B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F3108CA0-4C9B-4759-81F0B800AC83F24B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1978-01-01">January 1978</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/1FF60D6C-9082-41D7-AC4EDC10100A73E8_source.jpg?w=600" alt="Scientific American Magazine Vol 237 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/1FF60D6C-9082-41D7-AC4EDC10100A73E8_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/1FF60D6C-9082-41D7-AC4EDC10100A73E8_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-12-01">December 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/715342A8-A111-438A-9DBE0B366E3176C4_source.jpg?w=600" alt="Scientific American Magazine Vol 237 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/715342A8-A111-438A-9DBE0B366E3176C4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/715342A8-A111-438A-9DBE0B366E3176C4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-11-01">November 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/6451718D-E7CE-4C73-BFE4D8ACC6FEC45C_source.jpg?w=600" alt="Scientific American Magazine Vol 237 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/6451718D-E7CE-4C73-BFE4D8ACC6FEC45C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/6451718D-E7CE-4C73-BFE4D8ACC6FEC45C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-10-01">October 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C2B54A27-C342-4ACD-94CD38871B485B9D_source.jpg?w=600" alt="Scientific American Magazine Vol 237 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/C2B54A27-C342-4ACD-94CD38871B485B9D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C2B54A27-C342-4ACD-94CD38871B485B9D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-09-01">September 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/86BB8A2C-CDF6-4F83-AE2BDC73019570D1_source.jpg?w=600" alt="Scientific American Magazine Vol 237 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/86BB8A2C-CDF6-4F83-AE2BDC73019570D1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/86BB8A2C-CDF6-4F83-AE2BDC73019570D1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-08-01">August 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/FAB8634D-CBCE-4E15-B9F48B5E7DC9F9B9_source.jpg?w=600" alt="Scientific American Magazine Vol 237 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/FAB8634D-CBCE-4E15-B9F48B5E7DC9F9B9_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/FAB8634D-CBCE-4E15-B9F48B5E7DC9F9B9_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-07-01">July 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F3BE5561-9C15-47CE-825A1C012B134A41_source.jpg?w=600" alt="Scientific American Magazine Vol 236 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/F3BE5561-9C15-47CE-825A1C012B134A41_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F3BE5561-9C15-47CE-825A1C012B134A41_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-06-01">June 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/52C87D70-8310-4B24-BF0A584B81E5611A_source.jpg?w=600" alt="Scientific American Magazine Vol 236 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/52C87D70-8310-4B24-BF0A584B81E5611A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/52C87D70-8310-4B24-BF0A584B81E5611A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-05-01">May 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2A925571-9166-4610-8F2E3768B89F4146_source.jpg?w=600" alt="Scientific American Magazine Vol 236 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/2A925571-9166-4610-8F2E3768B89F4146_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2A925571-9166-4610-8F2E3768B89F4146_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-04-01">April 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/ADD27CCF-B4A7-4EDA-9C32B062C53F0EC0_source.jpg?w=600" alt="Scientific American Magazine Vol 236 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/ADD27CCF-B4A7-4EDA-9C32B062C53F0EC0_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/ADD27CCF-B4A7-4EDA-9C32B062C53F0EC0_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-03-01">March 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/6526A75E-0850-4ED1-983B16BF6F75E2FE_source.jpg?w=600" alt="Scientific American Magazine Vol 236 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/6526A75E-0850-4ED1-983B16BF6F75E2FE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/6526A75E-0850-4ED1-983B16BF6F75E2FE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-02-01">February 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1977/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/7721BC92-6CB3-4F3D-A7F8C652961C8682_source.jpg?w=600" alt="Scientific American Magazine Vol 236 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/7721BC92-6CB3-4F3D-A7F8C652961C8682_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/7721BC92-6CB3-4F3D-A7F8C652961C8682_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1977-01-01">January 1977</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/CEE3F645-C94E-42E8-81241285AC51D738_source.jpg?w=600" alt="Scientific American Magazine Vol 235 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/CEE3F645-C94E-42E8-81241285AC51D738_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/CEE3F645-C94E-42E8-81241285AC51D738_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-12-01">December 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9FC25F79-4063-4E33-B4FBDB1F2826DA5B_source.jpg?w=600" alt="Scientific American Magazine Vol 235 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/9FC25F79-4063-4E33-B4FBDB1F2826DA5B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9FC25F79-4063-4E33-B4FBDB1F2826DA5B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-11-01">November 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C0F26FBB-844A-4598-9A135FA8E687E57B_source.jpg?w=600" alt="Scientific American Magazine Vol 235 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/C0F26FBB-844A-4598-9A135FA8E687E57B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C0F26FBB-844A-4598-9A135FA8E687E57B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-10-01">October 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C2E74216-1C95-49FB-B751B11AFC54B858_source.jpg?w=600" alt="Scientific American Magazine Vol 235 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/C2E74216-1C95-49FB-B751B11AFC54B858_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C2E74216-1C95-49FB-B751B11AFC54B858_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-09-01">September 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/4FB3A9DD-0792-45EE-8D29B2C8C2874978_source.jpg?w=600" alt="Scientific American Magazine Vol 235 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/4FB3A9DD-0792-45EE-8D29B2C8C2874978_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/4FB3A9DD-0792-45EE-8D29B2C8C2874978_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-08-01">August 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9D93BA8F-FF1F-419E-890E368FA9861DED_source.jpg?w=600" alt="Scientific American Magazine Vol 235 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/9D93BA8F-FF1F-419E-890E368FA9861DED_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9D93BA8F-FF1F-419E-890E368FA9861DED_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-07-01">July 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/915A7E75-B0D5-40CE-A38A75FE785C5A25_source.jpg?w=600" alt="Scientific American Magazine Vol 234 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/915A7E75-B0D5-40CE-A38A75FE785C5A25_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/915A7E75-B0D5-40CE-A38A75FE785C5A25_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-06-01">June 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/449E78DF-4293-48E0-A7575986B1FE6AA6_source.jpg?w=600" alt="Scientific American Magazine Vol 234 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/449E78DF-4293-48E0-A7575986B1FE6AA6_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/449E78DF-4293-48E0-A7575986B1FE6AA6_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-05-01">May 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EF1FCE54-9471-497B-A779C14AFF4C2DF4_source.jpg?w=600" alt="Scientific American Magazine Vol 234 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/EF1FCE54-9471-497B-A779C14AFF4C2DF4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EF1FCE54-9471-497B-A779C14AFF4C2DF4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-04-01">April 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B6DF8947-F24D-462A-AC8B14ECBCDDF8B3_source.jpg?w=600" alt="Scientific American Magazine Vol 234 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/B6DF8947-F24D-462A-AC8B14ECBCDDF8B3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B6DF8947-F24D-462A-AC8B14ECBCDDF8B3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-03-01">March 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/38ED505C-299D-40AF-887CE0DAC25696CD_source.jpg?w=600" alt="Scientific American Magazine Vol 234 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/38ED505C-299D-40AF-887CE0DAC25696CD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/38ED505C-299D-40AF-887CE0DAC25696CD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-02-01">February 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1976/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/CF79FCF7-DBBF-4FEE-B28D6D291079339A_source.jpg?w=600" alt="Scientific American Magazine Vol 234 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/CF79FCF7-DBBF-4FEE-B28D6D291079339A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/CF79FCF7-DBBF-4FEE-B28D6D291079339A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1976-01-01">January 1976</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DB95A28C-EBB1-4A30-9E48677A9C45DEF9_source.jpg?w=600" alt="Scientific American Magazine Vol 233 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/DB95A28C-EBB1-4A30-9E48677A9C45DEF9_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DB95A28C-EBB1-4A30-9E48677A9C45DEF9_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-12-01">December 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/500304B0-5A42-4ADF-974025EF9D205805_source.jpg?w=600" alt="Scientific American Magazine Vol 233 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/500304B0-5A42-4ADF-974025EF9D205805_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/500304B0-5A42-4ADF-974025EF9D205805_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-11-01">November 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EEBE7BD7-1B83-4992-92C8A17F0E6D4010_source.jpg?w=600" alt="Scientific American Magazine Vol 233 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/EEBE7BD7-1B83-4992-92C8A17F0E6D4010_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EEBE7BD7-1B83-4992-92C8A17F0E6D4010_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-10-01">October 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/0E1866ED-5B66-4B40-B2DC2131BD3B8F65_source.jpg?w=600" alt="Scientific American Magazine Vol 233 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/0E1866ED-5B66-4B40-B2DC2131BD3B8F65_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/0E1866ED-5B66-4B40-B2DC2131BD3B8F65_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-09-01">September 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/10CE7102-E5D4-4C0B-916FBA1C3B4CC3A7_source.jpg?w=600" alt="Scientific American Magazine Vol 233 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/10CE7102-E5D4-4C0B-916FBA1C3B4CC3A7_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/10CE7102-E5D4-4C0B-916FBA1C3B4CC3A7_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-08-01">August 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/111BE245-37DC-4014-A4023DB29CDE01AC_source.jpg?w=600" alt="Scientific American Magazine Vol 233 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/111BE245-37DC-4014-A4023DB29CDE01AC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/111BE245-37DC-4014-A4023DB29CDE01AC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-07-01">July 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/302AA11B-C48F-4613-8A01692910363A6D_source.jpg?w=600" alt="Scientific American Magazine Vol 232 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/302AA11B-C48F-4613-8A01692910363A6D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/302AA11B-C48F-4613-8A01692910363A6D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-06-01">June 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8D931B92-BA92-4660-9DC37E5399600A14_source.jpg?w=600" alt="Scientific American Magazine Vol 232 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/8D931B92-BA92-4660-9DC37E5399600A14_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8D931B92-BA92-4660-9DC37E5399600A14_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-05-01">May 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/0292EA74-3D75-454C-8A431DF5E75A4F81_source.jpg?w=600" alt="Scientific American Magazine Vol 232 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/0292EA74-3D75-454C-8A431DF5E75A4F81_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/0292EA74-3D75-454C-8A431DF5E75A4F81_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-04-01">April 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EA9C0B60-25C3-4E10-99547061C496DA5D_source.jpg?w=600" alt="Scientific American Magazine Vol 232 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/EA9C0B60-25C3-4E10-99547061C496DA5D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EA9C0B60-25C3-4E10-99547061C496DA5D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-03-01">March 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/864D1966-B6D3-4F83-A3360CD5AD918E04_source.jpg?w=600" alt="Scientific American Magazine Vol 232 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/864D1966-B6D3-4F83-A3360CD5AD918E04_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/864D1966-B6D3-4F83-A3360CD5AD918E04_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-02-01">February 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1975/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/913BE270-38C0-4DB1-81AD857E232957D3_source.jpg?w=600" alt="Scientific American Magazine Vol 232 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/913BE270-38C0-4DB1-81AD857E232957D3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/913BE270-38C0-4DB1-81AD857E232957D3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1975-01-01">January 1975</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C7F76F9C-D15D-49CB-8F3C479FF037CEF5_source.jpg?w=600" alt="Scientific American Magazine Vol 231 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/C7F76F9C-D15D-49CB-8F3C479FF037CEF5_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C7F76F9C-D15D-49CB-8F3C479FF037CEF5_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-12-01">December 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/FC9D2B33-56DC-4B1A-B7D050F1B63DCD79_source.jpg?w=600" alt="Scientific American Magazine Vol 231 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/FC9D2B33-56DC-4B1A-B7D050F1B63DCD79_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/FC9D2B33-56DC-4B1A-B7D050F1B63DCD79_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-11-01">November 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/BBC543A1-813A-4C18-A24032387542B08A_source.jpg?w=600" alt="Scientific American Magazine Vol 231 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/BBC543A1-813A-4C18-A24032387542B08A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/BBC543A1-813A-4C18-A24032387542B08A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-10-01">October 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D6926152-1703-4AD7-BA1A0EB0EC910BD8_source.jpg?w=600" alt="Scientific American Magazine Vol 231 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/D6926152-1703-4AD7-BA1A0EB0EC910BD8_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D6926152-1703-4AD7-BA1A0EB0EC910BD8_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-09-01">September 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/470F2716-C3B1-41A5-8586C7EC14BD5D8F_source.jpg?w=600" alt="Scientific American Magazine Vol 231 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/470F2716-C3B1-41A5-8586C7EC14BD5D8F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/470F2716-C3B1-41A5-8586C7EC14BD5D8F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-08-01">August 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EE3E5D8F-3F6C-48D3-8832D0AE423D795B_source.jpg?w=600" alt="Scientific American Magazine Vol 231 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/EE3E5D8F-3F6C-48D3-8832D0AE423D795B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EE3E5D8F-3F6C-48D3-8832D0AE423D795B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-07-01">July 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2EC85C21-5D36-4154-B2E18E5747C1C8A4_source.jpg?w=600" alt="Scientific American Magazine Vol 230 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/2EC85C21-5D36-4154-B2E18E5747C1C8A4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2EC85C21-5D36-4154-B2E18E5747C1C8A4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-06-01">June 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/88B145AA-1AEC-4A18-BBC13F21769DD32B_source.jpg?w=600" alt="Scientific American Magazine Vol 230 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/88B145AA-1AEC-4A18-BBC13F21769DD32B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/88B145AA-1AEC-4A18-BBC13F21769DD32B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-05-01">May 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/41F9BDAD-5CD9-4BD7-B356FA38F5C712A5_source.jpg?w=600" alt="Scientific American Magazine Vol 230 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/41F9BDAD-5CD9-4BD7-B356FA38F5C712A5_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/41F9BDAD-5CD9-4BD7-B356FA38F5C712A5_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-04-01">April 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5B018A05-1648-4B10-96C6BE3FAC0286BF_source.jpg?w=600" alt="Scientific American Magazine Vol 230 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/5B018A05-1648-4B10-96C6BE3FAC0286BF_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5B018A05-1648-4B10-96C6BE3FAC0286BF_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-03-01">March 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A6D12C86-A834-4560-82C8A96BC12E5AA5_source.jpg?w=600" alt="Scientific American Magazine Vol 230 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/A6D12C86-A834-4560-82C8A96BC12E5AA5_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A6D12C86-A834-4560-82C8A96BC12E5AA5_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-02-01">February 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1974/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B308965C-E923-4DAA-9EC228C82942125D_source.jpg?w=600" alt="Scientific American Magazine Vol 230 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/B308965C-E923-4DAA-9EC228C82942125D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B308965C-E923-4DAA-9EC228C82942125D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1974-01-01">January 1974</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D0BA0173-03B4-4C66-BAB70CF69F6DFAFC_source.jpg?w=600" alt="Scientific American Magazine Vol 229 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/D0BA0173-03B4-4C66-BAB70CF69F6DFAFC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D0BA0173-03B4-4C66-BAB70CF69F6DFAFC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-12-01">December 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/6B9724EA-E8A8-411B-A38EE4563A44500B_source.jpg?w=600" alt="Scientific American Magazine Vol 229 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/6B9724EA-E8A8-411B-A38EE4563A44500B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/6B9724EA-E8A8-411B-A38EE4563A44500B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-11-01">November 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2BB5C609-5DA0-43DF-867C99236E6834AA_source.jpg?w=600" alt="Scientific American Magazine Vol 229 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/2BB5C609-5DA0-43DF-867C99236E6834AA_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2BB5C609-5DA0-43DF-867C99236E6834AA_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-10-01">October 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/0AB39537-39A2-4953-B450820A2700A4AF_source.jpg?w=600" alt="Scientific American Magazine Vol 229 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/0AB39537-39A2-4953-B450820A2700A4AF_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/0AB39537-39A2-4953-B450820A2700A4AF_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-09-01">September 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/420E5ADD-2CE6-4A2B-AD0D90AEEEE18BEA_source.jpg?w=600" alt="Scientific American Magazine Vol 229 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/420E5ADD-2CE6-4A2B-AD0D90AEEEE18BEA_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/420E5ADD-2CE6-4A2B-AD0D90AEEEE18BEA_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-08-01">August 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/447596FA-3210-43A2-A4ED3CBE648024CB_source.jpg?w=600" alt="Scientific American Magazine Vol 229 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/447596FA-3210-43A2-A4ED3CBE648024CB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/447596FA-3210-43A2-A4ED3CBE648024CB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-07-01">July 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/CA88F112-402B-4621-8C3CC33B8F1AE1D9_source.jpg?w=600" alt="Scientific American Magazine Vol 228 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/CA88F112-402B-4621-8C3CC33B8F1AE1D9_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/CA88F112-402B-4621-8C3CC33B8F1AE1D9_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-06-01">June 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/89AC13E7-B108-4FB4-A7E7F81B8274F3BB_source.jpg?w=600" alt="Scientific American Magazine Vol 228 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/89AC13E7-B108-4FB4-A7E7F81B8274F3BB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/89AC13E7-B108-4FB4-A7E7F81B8274F3BB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-05-01">May 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2C8EDC26-7968-475A-B3C2E55A6E3F2DDB_source.jpg?w=600" alt="Scientific American Magazine Vol 228 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/2C8EDC26-7968-475A-B3C2E55A6E3F2DDB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2C8EDC26-7968-475A-B3C2E55A6E3F2DDB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-04-01">April 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9F2CD8E0-8D59-48DA-84A31B1400033505_source.jpg?w=600" alt="Scientific American Magazine Vol 228 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/9F2CD8E0-8D59-48DA-84A31B1400033505_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9F2CD8E0-8D59-48DA-84A31B1400033505_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-03-01">March 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B4593A45-9CC4-44EC-89D5E7C9154EF9DD_source.jpg?w=600" alt="Scientific American Magazine Vol 228 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/B4593A45-9CC4-44EC-89D5E7C9154EF9DD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B4593A45-9CC4-44EC-89D5E7C9154EF9DD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-02-01">February 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1973/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/CF6103FF-B08F-4B74-891AC0AA32CE758D_source.jpg?w=600" alt="Scientific American Magazine Vol 228 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/CF6103FF-B08F-4B74-891AC0AA32CE758D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/CF6103FF-B08F-4B74-891AC0AA32CE758D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1973-01-01">January 1973</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F075D4B5-3581-4B3E-A55FA18629E34CCE_source.jpg?w=600" alt="Scientific American Magazine Vol 227 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/F075D4B5-3581-4B3E-A55FA18629E34CCE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F075D4B5-3581-4B3E-A55FA18629E34CCE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-12-01">December 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/1EFE0A3D-74CE-4B82-AC97618E4E26C7D7_source.jpg?w=600" alt="Scientific American Magazine Vol 227 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/1EFE0A3D-74CE-4B82-AC97618E4E26C7D7_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/1EFE0A3D-74CE-4B82-AC97618E4E26C7D7_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-11-01">November 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/62DFF55F-2B15-4D77-8E3D91A151F95D62_source.jpg?w=600" alt="Scientific American Magazine Vol 227 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/62DFF55F-2B15-4D77-8E3D91A151F95D62_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/62DFF55F-2B15-4D77-8E3D91A151F95D62_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-10-01">October 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8AB73427-DC40-4B87-91A6EF2C502A9FEF_source.jpg?w=600" alt="Scientific American Magazine Vol 227 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/8AB73427-DC40-4B87-91A6EF2C502A9FEF_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8AB73427-DC40-4B87-91A6EF2C502A9FEF_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-09-01">September 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/183530D3-CC72-4242-BBB2E5F50F432A8F_source.jpg?w=600" alt="Scientific American Magazine Vol 227 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/183530D3-CC72-4242-BBB2E5F50F432A8F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/183530D3-CC72-4242-BBB2E5F50F432A8F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-08-01">August 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D0FFF27A-AC1D-4CF1-8B7499C7B7CA161F_source.jpg?w=600" alt="Scientific American Magazine Vol 227 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/D0FFF27A-AC1D-4CF1-8B7499C7B7CA161F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D0FFF27A-AC1D-4CF1-8B7499C7B7CA161F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-07-01">July 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/3DBD491D-3658-4771-9F8425920CF50709_source.jpg?w=600" alt="Scientific American Magazine Vol 226 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/3DBD491D-3658-4771-9F8425920CF50709_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/3DBD491D-3658-4771-9F8425920CF50709_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-06-01">June 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8DAAC86F-1F44-41E0-B414745A9FD9A123_source.jpg?w=600" alt="Scientific American Magazine Vol 226 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/8DAAC86F-1F44-41E0-B414745A9FD9A123_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8DAAC86F-1F44-41E0-B414745A9FD9A123_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-05-01">May 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/AFC2CC5C-F338-4641-A25CDBFF3CBC6CC3_source.jpg?w=600" alt="Scientific American Magazine Vol 226 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/AFC2CC5C-F338-4641-A25CDBFF3CBC6CC3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/AFC2CC5C-F338-4641-A25CDBFF3CBC6CC3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-04-01">April 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/814ED532-BED1-4975-96266718FF00FF86_source.jpg?w=600" alt="Scientific American Magazine Vol 226 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/814ED532-BED1-4975-96266718FF00FF86_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/814ED532-BED1-4975-96266718FF00FF86_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-03-01">March 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B4BB7BE4-997F-4A32-A774A59250B3915E_source.jpg?w=600" alt="Scientific American Magazine Vol 226 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/B4BB7BE4-997F-4A32-A774A59250B3915E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B4BB7BE4-997F-4A32-A774A59250B3915E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-02-01">February 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1972/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/34246B2E-B2A6-4DF2-AEA779D7CD1C72F3_source.jpg?w=600" alt="Scientific American Magazine Vol 226 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/34246B2E-B2A6-4DF2-AEA779D7CD1C72F3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/34246B2E-B2A6-4DF2-AEA779D7CD1C72F3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1972-01-01">January 1972</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/7FC0D681-AC61-47DB-9C4EA5F0CFBD186C_source.jpg?w=600" alt="Scientific American Magazine Vol 225 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/7FC0D681-AC61-47DB-9C4EA5F0CFBD186C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/7FC0D681-AC61-47DB-9C4EA5F0CFBD186C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-12-01">December 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2022993C-CF1F-4580-B6D23A84CCCC2AB5_source.jpg?w=600" alt="Scientific American Magazine Vol 225 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/2022993C-CF1F-4580-B6D23A84CCCC2AB5_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2022993C-CF1F-4580-B6D23A84CCCC2AB5_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-11-01">November 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A3AACF43-257B-40AE-B951A4809A4BB7A0_source.jpg?w=600" alt="Scientific American Magazine Vol 225 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/A3AACF43-257B-40AE-B951A4809A4BB7A0_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A3AACF43-257B-40AE-B951A4809A4BB7A0_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-10-01">October 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A64EFC01-A138-4B58-90487E7A1C4B25B5_source.jpg?w=600" alt="Scientific American Magazine Vol 225 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/A64EFC01-A138-4B58-90487E7A1C4B25B5_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A64EFC01-A138-4B58-90487E7A1C4B25B5_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-09-01">September 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/201470A7-C773-4B80-ADD775C8D9BAD5FF_source.jpg?w=600" alt="Scientific American Magazine Vol 225 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/201470A7-C773-4B80-ADD775C8D9BAD5FF_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/201470A7-C773-4B80-ADD775C8D9BAD5FF_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-08-01">August 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/02DFDBE1-52F7-4E98-AEAE1A287A74C2CC_source.jpg?w=600" alt="Scientific American Magazine Vol 225 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/02DFDBE1-52F7-4E98-AEAE1A287A74C2CC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/02DFDBE1-52F7-4E98-AEAE1A287A74C2CC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-07-01">July 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/BD79C8ED-64EF-48EB-BA9C657240A5C9FC_source.jpg?w=600" alt="Scientific American Magazine Vol 224 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/BD79C8ED-64EF-48EB-BA9C657240A5C9FC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/BD79C8ED-64EF-48EB-BA9C657240A5C9FC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-06-01">June 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/0128F6B9-6317-461A-A16F15E11930895C_source.jpg?w=600" alt="Scientific American Magazine Vol 224 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/0128F6B9-6317-461A-A16F15E11930895C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/0128F6B9-6317-461A-A16F15E11930895C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-05-01">May 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2DE61568-D5B9-4BB1-8D041964473C52E4_source.jpg?w=600" alt="Scientific American Magazine Vol 224 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/2DE61568-D5B9-4BB1-8D041964473C52E4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2DE61568-D5B9-4BB1-8D041964473C52E4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-04-01">April 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/461511BE-6985-483A-ACE26D5955710028_source.jpg?w=600" alt="Scientific American Magazine Vol 224 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/461511BE-6985-483A-ACE26D5955710028_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/461511BE-6985-483A-ACE26D5955710028_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-03-01">March 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2B7C0817-A989-4114-A8B94B86F7D23C73_source.jpg?w=600" alt="Scientific American Magazine Vol 224 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/2B7C0817-A989-4114-A8B94B86F7D23C73_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2B7C0817-A989-4114-A8B94B86F7D23C73_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-02-01">February 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1971/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C72EB130-DB58-464B-ADDC1E8ED8CE52E2_source.jpg?w=600" alt="Scientific American Magazine Vol 224 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/C72EB130-DB58-464B-ADDC1E8ED8CE52E2_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C72EB130-DB58-464B-ADDC1E8ED8CE52E2_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1971-01-01">January 1971</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/60A23F1C-7CC6-450B-A88A4EBD47D1C3B7_source.jpg?w=600" alt="Scientific American Magazine Vol 223 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/60A23F1C-7CC6-450B-A88A4EBD47D1C3B7_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/60A23F1C-7CC6-450B-A88A4EBD47D1C3B7_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-12-01">December 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B53406CD-76AF-4783-A62688BD2F50185B_source.jpg?w=600" alt="Scientific American Magazine Vol 223 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/B53406CD-76AF-4783-A62688BD2F50185B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B53406CD-76AF-4783-A62688BD2F50185B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-11-01">November 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E40FD568-6117-4C0C-A22BCBE8E7B17BF4_source.jpg?w=600" alt="Scientific American Magazine Vol 223 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/E40FD568-6117-4C0C-A22BCBE8E7B17BF4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E40FD568-6117-4C0C-A22BCBE8E7B17BF4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-10-01">October 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/90806F89-25A5-4805-96905B202FA6A56A_source.jpg?w=600" alt="Scientific American Magazine Vol 223 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/90806F89-25A5-4805-96905B202FA6A56A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/90806F89-25A5-4805-96905B202FA6A56A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-09-01">September 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C48F8C17-AEEC-4474-9F3CE5FF77635D11_source.jpg?w=600" alt="Scientific American Magazine Vol 223 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/C48F8C17-AEEC-4474-9F3CE5FF77635D11_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C48F8C17-AEEC-4474-9F3CE5FF77635D11_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-08-01">August 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/899E5E34-7EC3-4A71-A16A31B16372C096_source.jpg?w=600" alt="Scientific American Magazine Vol 223 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/899E5E34-7EC3-4A71-A16A31B16372C096_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/899E5E34-7EC3-4A71-A16A31B16372C096_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-07-01">July 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/7AC365D2-DE44-49FD-B785B2969CC3E735_source.jpg?w=600" alt="Scientific American Magazine Vol 222 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/7AC365D2-DE44-49FD-B785B2969CC3E735_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/7AC365D2-DE44-49FD-B785B2969CC3E735_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-06-01">June 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5A40CA3C-9300-4FA9-AAED46B0C758E9E3_source.jpg?w=600" alt="Scientific American Magazine Vol 222 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/5A40CA3C-9300-4FA9-AAED46B0C758E9E3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5A40CA3C-9300-4FA9-AAED46B0C758E9E3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-05-01">May 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/3F02F824-7BE8-4986-9139F51F4C81F55B_source.jpg?w=600" alt="Scientific American Magazine Vol 222 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/3F02F824-7BE8-4986-9139F51F4C81F55B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/3F02F824-7BE8-4986-9139F51F4C81F55B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-04-01">April 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/34340EC9-3475-4846-A8610AD17F681F0C_source.jpg?w=600" alt="Scientific American Magazine Vol 222 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/34340EC9-3475-4846-A8610AD17F681F0C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/34340EC9-3475-4846-A8610AD17F681F0C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-03-01">March 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/27820B54-EADD-4ABE-81B4BE84002AE725_source.jpg?w=600" alt="Scientific American Magazine Vol 222 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/27820B54-EADD-4ABE-81B4BE84002AE725_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/27820B54-EADD-4ABE-81B4BE84002AE725_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-02-01">February 1970</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1970/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/AC67204D-B58E-467C-A1D6DFA0FDE7A799_source.jpg?w=600" alt="Scientific American Magazine Vol 222 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/AC67204D-B58E-467C-A1D6DFA0FDE7A799_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/AC67204D-B58E-467C-A1D6DFA0FDE7A799_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1970-01-01">January 1970</time></div></div></div></a></div></div></main><footer class="footer-VfsmT"><div class="footerContainer-pfbjC"><h2 class="footerMainText-wQ3og">Expand Your World with Science</h2></div><div class="footerFlexContainer-XKe5g footerContainer-pfbjC"><div class="footerLinks-m1THn"><p class="footerText-PzHcy">Learn and share the most exciting discoveries, innovations and ideas shaping our world today.</p><a class="footerLink-uRzI4" href="/getsciam/">Subscribe</a><a class="footerLink-uRzI4" href="/newsletters/">Sign up for our newsletters</a><a class="footerLink-uRzI4" href="/">See the latest stories</a><a class="footerLink-uRzI4" href="/latest-issue/">Read the latest issue</a><a class="footerLink-uRzI4" href="/getsciam/gift/">Give a Gift Subscription</a><p class="footerSocialMedia-7KIIV">Follow Us:<a href="https://www.instagram.com/scientific_american/?hl=en" target="_blank" alt="Instagram link" title="Instagram"><svg class="footerSocialIcon-UQyIx" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><path d="M224.1 141c-63.6 0-114.9 51.3-114.9 114.9s51.3 114.9 114.9 114.9S339 319.5 339 255.9 287.7 141 224.1 141zm0 189.6c-41.1 0-74.7-33.5-74.7-74.7s33.5-74.7 74.7-74.7 74.7 33.5 74.7 74.7-33.6 74.7-74.7 74.7zm146.4-194.3c0 14.9-12 26.8-26.8 26.8-14.9 0-26.8-12-26.8-26.8s12-26.8 26.8-26.8 26.8 12 26.8 26.8zm76.1 27.2c-1.7-35.9-9.9-67.7-36.2-93.9-26.2-26.2-58-34.4-93.9-36.2-37-2.1-147.9-2.1-184.9 0-35.8 1.7-67.6 9.9-93.9 36.1s-34.4 58-36.2 93.9c-2.1 37-2.1 147.9 0 184.9 1.7 35.9 9.9 67.7 36.2 93.9s58 34.4 93.9 36.2c37 2.1 147.9 2.1 184.9 0 35.9-1.7 67.7-9.9 93.9-36.2 26.2-26.2 34.4-58 36.2-93.9 2.1-37 2.1-147.8 0-184.8zM398.8 388c-7.8 19.6-22.9 34.7-42.6 42.6-29.5 11.7-99.5 9-132.1 9s-102.7 2.6-132.1-9c-19.6-7.8-34.7-22.9-42.6-42.6-11.7-29.5-9-99.5-9-132.1s-2.6-102.7 9-132.1c7.8-19.6 22.9-34.7 42.6-42.6 29.5-11.7 99.5-9 132.1-9s102.7-2.6 132.1 9c19.6 7.8 34.7 22.9 42.6 42.6 11.7 29.5 9 99.5 9 132.1s2.7 102.7-9 132.1z"></path></svg></a><a href="https://www.youtube.com/user/SciAmerican" target="_blank" alt="YouTube link" title="YouTube"><svg class="footerSocialIcon-UQyIx" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 576 512"><path d="M549.655 124.083c-6.281-23.65-24.787-42.276-48.284-48.597C458.781 64 288 64 288 64S117.22 64 74.629 75.486c-23.497 6.322-42.003 24.947-48.284 48.597-11.412 42.867-11.412 132.305-11.412 132.305s0 89.438 11.412 132.305c6.281 23.65 24.787 41.5 48.284 47.821C117.22 448 288 448 288 448s170.78 0 213.371-11.486c23.497-6.321 42.003-24.171 48.284-47.821 11.412-42.867 11.412-132.305 11.412-132.305s0-89.438-11.412-132.305zm-317.51 213.508V175.185l142.739 81.205-142.739 81.201z"></path></svg></a><a href="https://www.threads.net/@scientific_american" target="_blank" alt="Threads link" title="Threads"><svg class="footerSocialIcon-UQyIx" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><path d="M331.5 235.7c2.2.9 4.2 1.9 6.3 2.8c29.2 14.1 50.6 35.2 61.8 61.4c15.7 36.5 17.2 95.8-30.3 143.2c-36.2 36.2-80.3 52.5-142.6 53h-.3c-70.2-.5-124.1-24.1-160.4-70.2c-32.3-41-48.9-98.1-49.5-169.6v-.5c.5-71.5 17.1-128.6 49.4-169.6c36.3-46.1 90.3-69.7 160.5-70.2h.3c70.3.5 124.9 24 162.3 69.9c18.4 22.7 32 50 40.6 81.7l-40.4 10.8c-7.1-25.8-17.8-47.8-32.2-65.4c-29.2-35.8-73-54.2-130.5-54.6c-57 .5-100.1 18.8-128.2 54.4C72.1 146.1 58.5 194.3 58 256c.5 61.7 14.1 109.9 40.3 143.3c28 35.6 71.2 53.9 128.2 54.4c51.4-.4 85.4-12.6 113.7-40.9c32.3-32.2 31.7-71.8 21.4-95.9c-6.1-14.2-17.1-26-31.9-34.9c-3.7 26.9-11.8 48.3-24.7 64.8c-17.1 21.8-41.4 33.6-72.7 35.3c-23.6 1.3-46.3-4.4-63.9-16c-20.8-13.8-33-34.8-34.3-59.3c-2.5-48.3 35.7-83 95.2-86.4c21.1-1.2 40.9-.3 59.2 2.8c-2.4-14.8-7.3-26.6-14.6-35.2c-10-11.7-25.6-17.7-46.2-17.8h-.7c-16.6 0-39 4.6-53.3 26.3l-34.4-23.6c19.2-29.1 50.3-45.1 87.8-45.1h.8c62.6.4 99.9 39.5 103.7 107.7l-.2.2zm-156 68.8c1.3 25.1 28.4 36.8 54.6 35.3c25.6-1.4 54.6-11.4 59.5-73.2c-13.2-2.9-27.8-4.4-43.4-4.4c-4.8 0-9.6.1-14.4.4c-42.9 2.4-57.2 23.2-56.2 41.8z"></path></svg></a><a href="https://www.facebook.com/ScientificAmerican" target="_blank" alt="Facebook link" title="Facebook"><svg class="footerSocialIcon-UQyIx" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512"><path d="M279.14 288l14.22-92.66h-88.91v-60.13c0-25.35 12.42-50.06 52.24-50.06h40.42V6.26S260.43 0 225.36 0c-73.22 0-121.08 44.38-121.08 124.72v70.62H22.89V288h81.39v224h100.17V288z"></path></svg></a><a href="/platform/syndication/rss/" target="_blank" alt="RSS feed" title="RSS feed"><svg class="footerSocialIcon-UQyIx" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><path d="M0 64C0 46.3 14.3 32 32 32c229.8 0 416 186.2 416 416c0 17.7-14.3 32-32 32s-32-14.3-32-32C384 253.6 226.4 96 32 96C14.3 96 0 81.7 0 64zM0 416a64 64 0 1 1 128 0A64 64 0 1 1 0 416zM32 160c159.1 0 288 128.9 288 288c0 17.7-14.3 32-32 32s-32-14.3-32-32c0-123.7-100.3-224-224-224c-17.7 0-32-14.3-32-32s14.3-32 32-32z"></path></svg></a></p></div><div class="footerImageContainer-omuef"><img class="footerImage-fMFhw" src="/static/assets/footerProductImg-f6732134.png" alt="Scientific American publications in print & digital formats" as="image" loading="lazy"/></div></div><div class="grid-c0--6 footerContainer-pfbjC"><div><ul><li><a class="footerSmallLink-tZvCu" href="/page/return-refund-policy/">Return & Refund Policy</a></li><li><a class="footerSmallLink-tZvCu" href="/page/about-scientific-american/">About</a></li><li><a class="footerSmallLink-tZvCu" href="/pressroom/">Press Room</a></li></ul></div><div><ul class="footer-links"><li><a class="footerSmallLink-tZvCu" href="/page/frequently-asked-questions/subscriptions-products/">FAQs</a></li><li><a class="footerSmallLink-tZvCu" href="/page/contact-us/customer-service/">Contact Us</a></li><li><a class="footerSmallLink-tZvCu" href="/page/international/">International Editions</a></li></ul></div><div><ul class="footer-links"><li><a class="footerSmallLink-tZvCu" href="/mediakit/">Advertise</a></li><li><a class="footerSmallLink-tZvCu" href="/accessibility-statement/">Accessibility Statement</a></li><li><a class="footerSmallLink-tZvCu" href="/page/terms-of-use/">Terms of Use</a></li></ul></div><div><ul class="footer-links"><li><a class="footerSmallLink-tZvCu" href="/page/privacy-policy/">Privacy Policy</a></li><li><a class="footerSmallLink-tZvCu" href="/page/california-consumer-privacy-statement/">California Consumer Privacy Statement</a></li><li><a class="footerSmallLink-tZvCu" href="#">Use of cookies/Do not sell my data</a></li></ul></div></div><div class="footerContainer-pfbjC"><p>Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www.springernature.com/us). Scientific American maintains a strict policy of editorial independence in reporting developments in science to our readers.</p><p>漏 2024 SCIENTIFIC AMERICAN, A DIVISION OF SPRINGER NATURE AMERICA, INC.<br/>ALL RIGHTS RESERVED.</p></div></footer></div> <script id="__DATA__">window.__DATA__=JSON.parse(`{"initialData":{"issues":[{"contentful_id":"5iFCnNrL9Iu0u7QDxhCgUG","mura_id":null,"path":"/issue/sa/1979/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 241, Issue 6","volume":241,"issue":"6","issue_date":"1979-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/84E04900-D9ED-4C17-891C5C9D4109C9FA.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/BD879661-F7EF-4936-8FEC7548ABBDBE30_source.jpg","image_width":440,"image_height":621,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1jYikNnmUiaoYo06ZW673a","mura_id":null,"path":"/issue/sa/1979/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 241, Issue 5","volume":241,"issue":"5","issue_date":"1979-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/7444C06E-BA90-4200-9B44B8168476F9DB.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/5695F82F-6A4C-4220-871F3DC6BDE977E4_source.jpg","image_width":440,"image_height":612,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2jSyeRtAYaEbTewukUFfcg","mura_id":null,"path":"/issue/sa/1979/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 241, Issue 4","volume":241,"issue":"4","issue_date":"1979-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/E8FA39BB-E256-406C-B64DC44AD17C4FE7.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/69CF0F9D-3FB5-41CA-B9F7186231446D55_source.jpg","image_width":440,"image_height":610,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5avIGylQ9XcLAfQzp0DUW0","mura_id":null,"path":"/issue/sa/1979/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 241, Issue 3","volume":241,"issue":"3","issue_date":"1979-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/82AF9553-5845-4F7D-A2F72192784C413D.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/A60DEA28-AAC7-45E0-AF379D83B56DC639_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5vPU0MJHTeQKlk575oAWCW","mura_id":null,"path":"/issue/sa/1979/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 241, Issue 2","volume":241,"issue":"2","issue_date":"1979-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/DF650C63-A2FE-4C41-845136465F9BF98E.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/044C9C10-0CE3-4AFE-B89EAB46965F4247_source.jpg","image_width":440,"image_height":600,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3rTEYx6Gtysh57GxcNfCnX","mura_id":null,"path":"/issue/sa/1979/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 241, Issue 1","volume":241,"issue":"1","issue_date":"1979-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/02F20AEA-B08D-42EF-B83AE960C8F4D392.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/722389B4-4574-44D2-ADA0F4247E281462_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4ou42l2ImB0HsqU51fYJ4y","mura_id":null,"path":"/issue/sa/1979/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 240, Issue 6","volume":240,"issue":"6","issue_date":"1979-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/DD5F6E21-022C-4068-A98BC20CCF990EED.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/FF430073-5064-4096-B4A5A3665CDAFDD7_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4n4UR3yiY9RPhFYmrVm0s5","mura_id":null,"path":"/issue/sa/1979/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 240, Issue 5","volume":240,"issue":"5","issue_date":"1979-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/D0511C3E-2914-4708-A1D2C5ABFB078745.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/509BFF54-BB92-43DD-80B0BBBD5871F961_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6Q1WqbSvt6Yil0u3T1qmvW","mura_id":null,"path":"/issue/sa/1979/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 240, Issue 4","volume":240,"issue":"4","issue_date":"1979-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/38C2AF54-5372-430F-B204021805E818BB.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/89918C7B-599F-4261-AB40679155C09880_source.jpg","image_width":440,"image_height":618,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"dHX4SZTH2Et1bFoPHuGGU","mura_id":null,"path":"/issue/sa/1979/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 240, Issue 3","volume":240,"issue":"3","issue_date":"1979-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/CB837088-B4E3-4485-8D7176C97CD2A339.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/80914847-72EC-486C-87E51E69301B6365_source.jpg","image_width":440,"image_height":608,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1buuW8ruMTCXo7KNybzbkx","mura_id":null,"path":"/issue/sa/1979/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 240, Issue 2","volume":240,"issue":"2","issue_date":"1979-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/76BAACAF-2DA5-4941-9FB2CCCA7C0430CD.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/11072C04-A629-408C-B65E9F60DA8287BE_source.jpg","image_width":440,"image_height":618,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"28Ree33mNkGYPTkGWVlBDn","mura_id":null,"path":"/issue/sa/1979/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 240, Issue 1","volume":240,"issue":"1","issue_date":"1979-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/3E110C4A-CE27-450C-B5AEF9C90B305C2F.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/B5418E39-7712-4EE1-A13BAA9071D8DA7A_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4uJ1WcE3KDfWXDKclig0jE","mura_id":null,"path":"/issue/sa/1978/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 239, Issue 6","volume":239,"issue":"6","issue_date":"1978-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8482DCE1-A3DE-4B7B-808D0E91FDACFB21.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/30FB08EB-D23B-4D74-8E9617EA3C037415_source.jpg","image_width":440,"image_height":615,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"19PY2ulCLg4WbwJ0UGtxeC","mura_id":null,"path":"/issue/sa/1978/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 239, Issue 5","volume":239,"issue":"5","issue_date":"1978-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/B9FDA2D2-BD9A-46F3-A56B3315CDB6086F.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2778F77E-A3E3-4462-909BAE2A20176DC4_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3YQ4t78jQwcRhAxezFBlrm","mura_id":null,"path":"/issue/sa/1978/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 239, Issue 4","volume":239,"issue":"4","issue_date":"1978-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/F00D9FDF-E90F-4702-8810A1195A0D4168.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/9430BAA1-065D-4668-95C45FF20FA79764_source.jpg","image_width":440,"image_height":611,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"13vINEjIGIeWk9BXrxhmyv","mura_id":null,"path":"/issue/sa/1978/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 239, Issue 3","volume":239,"issue":"3","issue_date":"1978-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/1EB5877A-09FB-4986-BF5D8429B5048FC4.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/67959A48-7665-48AB-81DDB7CE1BD3EC63_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2smDQPoLV4PSEf8x3kH1iT","mura_id":null,"path":"/issue/sa/1978/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 239, Issue 2","volume":239,"issue":"2","issue_date":"1978-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8F22FE0F-6CCE-497A-BBF8B5224285897F.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/232B1BB6-7922-4BD7-81BB17009329ABC3_source.jpg","image_width":440,"image_height":615,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3ujj1HCIyVWQejXZp4gHPF","mura_id":null,"path":"/issue/sa/1978/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 239, Issue 1","volume":239,"issue":"1","issue_date":"1978-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/1BF05113-53E4-4ED8-83A034BB3DCCECCD.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/DFC968BE-9D13-4887-A5CF921812780F0D_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3wqTfklApeSmI8n51p7FBb","mura_id":null,"path":"/issue/sa/1978/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 238, Issue 6","volume":238,"issue":"6","issue_date":"1978-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/AE96C6A0-01B4-47EB-AE6FE0D0292B1CC3.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/80366D8F-5C8C-4C0A-8D6096B91F814B3B_source.jpg","image_width":440,"image_height":606,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5F8VfyBuWBbhqWUXaB3sVv","mura_id":null,"path":"/issue/sa/1978/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 238, Issue 5","volume":238,"issue":"5","issue_date":"1978-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/89E7254F-BE83-4D11-936F1B1217DB4017.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/7329B9DC-BD11-45D0-B8B2DB615655B0EA_source.jpg","image_width":440,"image_height":601,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3rlAeh91hS7td9CSkM4NZN","mura_id":null,"path":"/issue/sa/1978/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 238, Issue 4","volume":238,"issue":"4","issue_date":"1978-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/60B3B808-5CC4-41B5-86DD9C0A8EDCB3AD.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/BA7BD179-BB54-4441-B825CD1851ECF715_source.jpg","image_width":440,"image_height":598,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6J9xtFtTpHRKWGOdveTiv5","mura_id":null,"path":"/issue/sa/1978/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 238, Issue 3","volume":238,"issue":"3","issue_date":"1978-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/4237BB3A-B212-4B7C-A304408154A5306E.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/85590875-BA08-434D-B899C1EFB8BC0AC2_source.jpg","image_width":440,"image_height":612,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3iyjBgOfL25JbxfxfvtV9o","mura_id":null,"path":"/issue/sa/1978/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 238, Issue 2","volume":238,"issue":"2","issue_date":"1978-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/26B66D21-AC12-4D45-94CFD51734D80651.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/6F6B51E7-FD0F-4C41-B7F8C65C234F6531_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3t3kTG3HNOkFRnRAMELvPQ","mura_id":null,"path":"/issue/sa/1978/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 238, Issue 1","volume":238,"issue":"1","issue_date":"1978-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/95398720-8BB7-4305-A1E82FBA74AE2491.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/F3108CA0-4C9B-4759-81F0B800AC83F24B_source.jpg","image_width":440,"image_height":606,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5xl8JcSRuy8i307GlSVeNn","mura_id":null,"path":"/issue/sa/1977/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 237, Issue 6","volume":237,"issue":"6","issue_date":"1977-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/817F3156-B390-4288-A4F01CE57CCF46C8.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/1FF60D6C-9082-41D7-AC4EDC10100A73E8_source.jpg","image_width":440,"image_height":610,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"79T4BeYdw7O7XJis4idMWh","mura_id":null,"path":"/issue/sa/1977/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 237, Issue 5","volume":237,"issue":"5","issue_date":"1977-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/36EBB802-ED59-46C7-8E4642DAB6E94CB7.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/715342A8-A111-438A-9DBE0B366E3176C4_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"9dH1wXVUqfaE1bLgJH5JE","mura_id":null,"path":"/issue/sa/1977/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 237, Issue 4","volume":237,"issue":"4","issue_date":"1977-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/532CF89D-CDFA-488F-89694F392F5E0442.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/6451718D-E7CE-4C73-BFE4D8ACC6FEC45C_source.jpg","image_width":440,"image_height":597,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6IIfvHYLFVSU9jj341QrVr","mura_id":null,"path":"/issue/sa/1977/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 237, Issue 3","volume":237,"issue":"3","issue_date":"1977-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/A6AD1AD7-DAAB-4197-AC2FFF2CBB96D737.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/C2B54A27-C342-4ACD-94CD38871B485B9D_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1dkgQvyOurW2nCDjttVewa","mura_id":null,"path":"/issue/sa/1977/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 237, Issue 2","volume":237,"issue":"2","issue_date":"1977-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/E3350634-CB48-44F2-B3A103F4998EE6EF.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/86BB8A2C-CDF6-4F83-AE2BDC73019570D1_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"LV0y3qSs6pjuC5YPiBvh5","mura_id":null,"path":"/issue/sa/1977/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 237, Issue 1","volume":237,"issue":"1","issue_date":"1977-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/877C6464-EE27-434F-9D8D06339C95D0BA.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/FAB8634D-CBCE-4E15-B9F48B5E7DC9F9B9_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4csRff3y2MDGJDVy5ZOx6X","mura_id":null,"path":"/issue/sa/1977/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 236, Issue 6","volume":236,"issue":"6","issue_date":"1977-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/743791C5-F84C-4387-B6928B2E3EC2B54A.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/F3BE5561-9C15-47CE-825A1C012B134A41_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"36B92STH7d3UQHgyLIn8PV","mura_id":null,"path":"/issue/sa/1977/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 236, Issue 5","volume":236,"issue":"5","issue_date":"1977-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/0D0F9059-9A46-4129-BC5FE9FED2B302F8.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/52C87D70-8310-4B24-BF0A584B81E5611A_source.jpg","image_width":440,"image_height":642,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7jW6Ul3ROaFNB9jZbGmuTy","mura_id":null,"path":"/issue/sa/1977/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 236, Issue 4","volume":236,"issue":"4","issue_date":"1977-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/22030921-E58D-4548-8B0724D4462796BC.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2A925571-9166-4610-8F2E3768B89F4146_source.jpg","image_width":440,"image_height":618,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5tIvzzfgsnomY37ZTselO1","mura_id":null,"path":"/issue/sa/1977/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 236, Issue 3","volume":236,"issue":"3","issue_date":"1977-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/BA8AE562-8AB4-41C4-A6E5C45BC88BEA0B.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/ADD27CCF-B4A7-4EDA-9C32B062C53F0EC0_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3i6eKiSVlymw0vjnadbDzT","mura_id":null,"path":"/issue/sa/1977/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 236, Issue 2","volume":236,"issue":"2","issue_date":"1977-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/1C732050-DEA6-4B0E-BFC6B95E60EE5B98.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/6526A75E-0850-4ED1-983B16BF6F75E2FE_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2qXZ2fJtkYLjEItOSpRMJa","mura_id":null,"path":"/issue/sa/1977/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 236, Issue 1","volume":236,"issue":"1","issue_date":"1977-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/46DF9252-2F73-4A72-8379AB7D78A87A87.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/7721BC92-6CB3-4F3D-A7F8C652961C8682_source.jpg","image_width":440,"image_height":606,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"310Tng0rHmk7I4mZlsMOo6","mura_id":null,"path":"/issue/sa/1976/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 235, Issue 6","volume":235,"issue":"6","issue_date":"1976-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/3187DF52-777C-4426-944D766820819B6A.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/CEE3F645-C94E-42E8-81241285AC51D738_source.jpg","image_width":440,"image_height":610,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3oAeTFaWxGWtzItlxUMFvG","mura_id":null,"path":"/issue/sa/1976/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 235, Issue 5","volume":235,"issue":"5","issue_date":"1976-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/3DDB6408-2623-40C5-95B5858ED2A2BC9B.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/9FC25F79-4063-4E33-B4FBDB1F2826DA5B_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1qqivbtgG5EiF11m8csZOA","mura_id":null,"path":"/issue/sa/1976/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 235, Issue 4","volume":235,"issue":"4","issue_date":"1976-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/866EE7A9-05EC-469B-AE3E007E8781C1CC.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/C0F26FBB-844A-4598-9A135FA8E687E57B_source.jpg","image_width":440,"image_height":597,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6vntf6Fks48y77zEc5MjgY","mura_id":null,"path":"/issue/sa/1976/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 235, Issue 3","volume":235,"issue":"3","issue_date":"1976-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/0A27863E-DD25-4814-8CB30F1AFC1832B1.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/C2E74216-1C95-49FB-B751B11AFC54B858_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3B7zUi7scYK8huOjmX4YGv","mura_id":null,"path":"/issue/sa/1976/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 235, Issue 2","volume":235,"issue":"2","issue_date":"1976-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/537B7827-47E1-4A2E-9C4BFFF7A7E84564.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/4FB3A9DD-0792-45EE-8D29B2C8C2874978_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7qHqXsDRgnHIzwnxCqVADT","mura_id":null,"path":"/issue/sa/1976/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 235, Issue 1","volume":235,"issue":"1","issue_date":"1976-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/B5985F1E-9CB8-42DE-927CA7281B482545.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/9D93BA8F-FF1F-419E-890E368FA9861DED_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7gXiwYZxLKpqIQmFuNCj6m","mura_id":null,"path":"/issue/sa/1976/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 234, Issue 6","volume":234,"issue":"6","issue_date":"1976-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/F6C2702C-2875-455B-81D30C13C5D0DB6E.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/915A7E75-B0D5-40CE-A38A75FE785C5A25_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2woP6PrORh8ia7TWyRel8N","mura_id":null,"path":"/issue/sa/1976/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 234, Issue 5","volume":234,"issue":"5","issue_date":"1976-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/7E540353-B2F9-4888-B7DDD07017718D23.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/449E78DF-4293-48E0-A7575986B1FE6AA6_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7rVhm3tuiNSo5oyRybpZbR","mura_id":null,"path":"/issue/sa/1976/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 234, Issue 4","volume":234,"issue":"4","issue_date":"1976-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/B3858D41-A1E2-4213-8DA4CB517A6DFD8A.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/EF1FCE54-9471-497B-A779C14AFF4C2DF4_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"Prg8MkJis13KUuRFpKCNz","mura_id":null,"path":"/issue/sa/1976/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 234, Issue 3","volume":234,"issue":"3","issue_date":"1976-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/9AF22B04-2CA7-4B61-AF23464BC2F8D73A.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/B6DF8947-F24D-462A-AC8B14ECBCDDF8B3_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1YXqJeieaP7ZVdOrKEjqBf","mura_id":null,"path":"/issue/sa/1976/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 234, Issue 2","volume":234,"issue":"2","issue_date":"1976-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/0689FA55-79CF-4846-A2F0930DA0F40317.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/38ED505C-299D-40AF-887CE0DAC25696CD_source.jpg","image_width":440,"image_height":597,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3wn2eSEQqEnuEOpvH4hxOE","mura_id":null,"path":"/issue/sa/1976/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 234, Issue 1","volume":234,"issue":"1","issue_date":"1976-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/D734C111-B5C8-4CF6-B22BAE90D1E20126.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/CF79FCF7-DBBF-4FEE-B28D6D291079339A_source.jpg","image_width":440,"image_height":600,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"76prYGAY4uEYtmkymsg8aJ","mura_id":null,"path":"/issue/sa/1975/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 233, Issue 6","volume":233,"issue":"6","issue_date":"1975-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/CCF7186B-B44B-4157-8ABB1C34554E00B7.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/DB95A28C-EBB1-4A30-9E48677A9C45DEF9_source.jpg","image_width":440,"image_height":622,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4LMtz3kpYH32o97El3vZAS","mura_id":null,"path":"/issue/sa/1975/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 233, Issue 5","volume":233,"issue":"5","issue_date":"1975-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/65490A6E-66AC-4152-8DFE1414C1643C9C.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/500304B0-5A42-4ADF-974025EF9D205805_source.jpg","image_width":440,"image_height":604,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5FpofKELMrmwglmfkBjl4y","mura_id":null,"path":"/issue/sa/1975/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 233, Issue 4","volume":233,"issue":"4","issue_date":"1975-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/39F84CC0-A3F6-4AFF-87DFE704C56F39C9.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/EEBE7BD7-1B83-4992-92C8A17F0E6D4010_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5oNoIM50Ni6qeCKz0f5HPa","mura_id":null,"path":"/issue/sa/1975/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 233, Issue 3","volume":233,"issue":"3","issue_date":"1975-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/BC1585E7-E149-4865-9E0937BFD768098D.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/0E1866ED-5B66-4B40-B2DC2131BD3B8F65_source.jpg","image_width":440,"image_height":600,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6celF46qOa9XhJ6KQLUVgB","mura_id":null,"path":"/issue/sa/1975/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 233, Issue 2","volume":233,"issue":"2","issue_date":"1975-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8E065AEE-8B8F-4FC3-9745EEA51D305A3E.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/10CE7102-E5D4-4C0B-916FBA1C3B4CC3A7_source.jpg","image_width":440,"image_height":620,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"34NylhvdP5hzWtenbr94Nm","mura_id":null,"path":"/issue/sa/1975/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 233, Issue 1","volume":233,"issue":"1","issue_date":"1975-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/987C38EA-1DAD-4697-B2A889E3A3C226D6.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/111BE245-37DC-4014-A4023DB29CDE01AC_source.jpg","image_width":440,"image_height":622,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"53oknfGwiogQKFePhvUdj9","mura_id":null,"path":"/issue/sa/1975/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 232, Issue 6","volume":232,"issue":"6","issue_date":"1975-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/932503C1-8FBC-4CE5-97DECAF8A62A333E.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/302AA11B-C48F-4613-8A01692910363A6D_source.jpg","image_width":440,"image_height":612,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6SsAkYfWdpYhOUwikYSkun","mura_id":null,"path":"/issue/sa/1975/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 232, Issue 5","volume":232,"issue":"5","issue_date":"1975-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/C5588863-AE4B-4D10-81C78367738A086A.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/8D931B92-BA92-4660-9DC37E5399600A14_source.jpg","image_width":440,"image_height":615,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"RdEs5IqXHeM52VQ217GMU","mura_id":null,"path":"/issue/sa/1975/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 232, Issue 4","volume":232,"issue":"4","issue_date":"1975-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/C4464921-D687-439E-9DBD9E645698D825.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/0292EA74-3D75-454C-8A431DF5E75A4F81_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1X0xzivIpYz9P2Uj4GbjmO","mura_id":null,"path":"/issue/sa/1975/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 232, Issue 3","volume":232,"issue":"3","issue_date":"1975-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/854EE0FA-B027-442E-AD03BAE47C5CCCFE.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/EA9C0B60-25C3-4E10-99547061C496DA5D_source.jpg","image_width":440,"image_height":614,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"q6xa4RUHJsu5vjf7WThe0","mura_id":null,"path":"/issue/sa/1975/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 232, Issue 2","volume":232,"issue":"2","issue_date":"1975-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/1F1E8C98-D8E3-4A61-A9792BFA56D1CF8D.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/864D1966-B6D3-4F83-A3360CD5AD918E04_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"41sxYmfQaN1QFQXMuyVL6y","mura_id":null,"path":"/issue/sa/1975/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 232, Issue 1","volume":232,"issue":"1","issue_date":"1975-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/E44A4D79-E48C-4C2E-937F527B0E053232.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/913BE270-38C0-4DB1-81AD857E232957D3_source.jpg","image_width":440,"image_height":616,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"42chk0hErVfFouiBg2rGJO","mura_id":null,"path":"/issue/sa/1974/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 231, Issue 6","volume":231,"issue":"6","issue_date":"1974-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/5F350A52-7F24-4BAC-8ED96467843F2951.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/C7F76F9C-D15D-49CB-8F3C479FF037CEF5_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4Eo2y6aJR5cjblbIsm8SIg","mura_id":null,"path":"/issue/sa/1974/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 231, Issue 5","volume":231,"issue":"5","issue_date":"1974-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/62499722-BF09-4915-B81F8FBB0CD093CC.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/FC9D2B33-56DC-4B1A-B7D050F1B63DCD79_source.jpg","image_width":440,"image_height":611,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"jvV3O0KDXgZYIS1C5n6jD","mura_id":null,"path":"/issue/sa/1974/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 231, Issue 4","volume":231,"issue":"4","issue_date":"1974-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/93D3561C-AE36-47C0-A839D1BE91B7BE93.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/BBC543A1-813A-4C18-A24032387542B08A_source.jpg","image_width":440,"image_height":611,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2qNuVsUlrlmVYmax5wqp3p","mura_id":null,"path":"/issue/sa/1974/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 231, Issue 3","volume":231,"issue":"3","issue_date":"1974-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/BDE7A0FF-AD0F-4E8D-9706D6FAA51114D5.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/D6926152-1703-4AD7-BA1A0EB0EC910BD8_source.jpg","image_width":440,"image_height":612,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2XL0kgkjOjLwQhlQd7irTe","mura_id":null,"path":"/issue/sa/1974/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 231, Issue 2","volume":231,"issue":"2","issue_date":"1974-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/C877D4A8-8EBF-486D-89006C8EEF709376.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/470F2716-C3B1-41A5-8586C7EC14BD5D8F_source.jpg","image_width":440,"image_height":616,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7ApK5iQo3AuqyUeADIYIh1","mura_id":null,"path":"/issue/sa/1974/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 231, Issue 1","volume":231,"issue":"1","issue_date":"1974-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/D3A77F84-D34D-4E4E-8F3B6EB4FC938185.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/EE3E5D8F-3F6C-48D3-8832D0AE423D795B_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2LPUSe7HXjDdt8epI0VQa6","mura_id":null,"path":"/issue/sa/1974/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 230, Issue 6","volume":230,"issue":"6","issue_date":"1974-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/5C1AB833-3B0E-4C40-BE156A14320DBB2D.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2EC85C21-5D36-4154-B2E18E5747C1C8A4_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"c4L2JZUeDUKHHLZYLw0ZD","mura_id":null,"path":"/issue/sa/1974/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 230, Issue 5","volume":230,"issue":"5","issue_date":"1974-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/80AB76D9-9E9B-4332-9CB0E75A00800385.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/88B145AA-1AEC-4A18-BBC13F21769DD32B_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3QS8J3OCPtGq4ZhLwKfMQr","mura_id":null,"path":"/issue/sa/1974/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 230, Issue 4","volume":230,"issue":"4","issue_date":"1974-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/7416B8A8-60CE-45D0-A4DAD3426E0550E6.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/41F9BDAD-5CD9-4BD7-B356FA38F5C712A5_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1vnIRwpCbqHi22lbzkBugW","mura_id":null,"path":"/issue/sa/1974/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 230, Issue 3","volume":230,"issue":"3","issue_date":"1974-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/A53EBF41-EFBC-49B1-9F28AA6ACB4487EF.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/5B018A05-1648-4B10-96C6BE3FAC0286BF_source.jpg","image_width":440,"image_height":616,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4fGGTS3HOlDuDH6s8wJPjB","mura_id":null,"path":"/issue/sa/1974/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 230, Issue 2","volume":230,"issue":"2","issue_date":"1974-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/7530CF45-B2E5-4691-BABEC484DF6F717B.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/A6D12C86-A834-4560-82C8A96BC12E5AA5_source.jpg","image_width":440,"image_height":619,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6Xlpod6YGnRX3Qv5xromSJ","mura_id":null,"path":"/issue/sa/1974/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 230, Issue 1","volume":230,"issue":"1","issue_date":"1974-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/EC231284-670B-4C5F-AF5E930BF8F27C40.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/B308965C-E923-4DAA-9EC228C82942125D_source.jpg","image_width":440,"image_height":613,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7vzvXwzgQCddT5e2Vx3IOF","mura_id":null,"path":"/issue/sa/1973/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 229, Issue 6","volume":229,"issue":"6","issue_date":"1973-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/D9A458FF-650F-49B8-BCE9E789D1476491.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/D0BA0173-03B4-4C66-BAB70CF69F6DFAFC_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5A7LXhWXBPrRb32gYRXFZ6","mura_id":null,"path":"/issue/sa/1973/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 229, Issue 5","volume":229,"issue":"5","issue_date":"1973-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/159600C4-6AF7-4842-A3961F478A7C9212.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/6B9724EA-E8A8-411B-A38EE4563A44500B_source.jpg","image_width":440,"image_height":616,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3u8UjMLq8NxsiQyI5zfQAv","mura_id":null,"path":"/issue/sa/1973/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 229, Issue 4","volume":229,"issue":"4","issue_date":"1973-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/65981227-90C7-4995-843110729477B44D.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2BB5C609-5DA0-43DF-867C99236E6834AA_source.jpg","image_width":440,"image_height":598,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2FJSgXduNBaelGozZwA7Le","mura_id":null,"path":"/issue/sa/1973/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 229, Issue 3","volume":229,"issue":"3","issue_date":"1973-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/9E17A132-7F9E-4309-82A00D08DAE25F09.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/0AB39537-39A2-4953-B450820A2700A4AF_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3gxSb6UbjQJPKMpNLS6Jag","mura_id":null,"path":"/issue/sa/1973/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 229, Issue 2","volume":229,"issue":"2","issue_date":"1973-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8855865E-249E-4191-82DC82AFBED03736.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/420E5ADD-2CE6-4A2B-AD0D90AEEEE18BEA_source.jpg","image_width":440,"image_height":616,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"65ayTcNCvuBotTs8qTTuMf","mura_id":null,"path":"/issue/sa/1973/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 229, Issue 1","volume":229,"issue":"1","issue_date":"1973-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/620BEAFA-B529-4D9F-8CD3F93BC4CBC8B2.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/447596FA-3210-43A2-A4ED3CBE648024CB_source.jpg","image_width":440,"image_height":611,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5RuW8IWfHjolfN8vBNM8Ka","mura_id":null,"path":"/issue/sa/1973/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 228, Issue 6","volume":228,"issue":"6","issue_date":"1973-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/40183318-1B95-4A59-9ECABF27844036FE.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/CA88F112-402B-4621-8C3CC33B8F1AE1D9_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"43uaPeqtNINRuzA7srmybl","mura_id":null,"path":"/issue/sa/1973/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 228, Issue 5","volume":228,"issue":"5","issue_date":"1973-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8954C8F0-78CE-4335-8046D855D915979A.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/89AC13E7-B108-4FB4-A7E7F81B8274F3BB_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2B7cnG2Ey5Mwa1SH8QdH25","mura_id":null,"path":"/issue/sa/1973/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 228, Issue 4","volume":228,"issue":"4","issue_date":"1973-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/D5E0D461-22BF-4DF2-986117C42CB219FD.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2C8EDC26-7968-475A-B3C2E55A6E3F2DDB_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3lapSY9YAzHQbkeKr6adCK","mura_id":null,"path":"/issue/sa/1973/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 228, Issue 3","volume":228,"issue":"3","issue_date":"1973-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/CBBEFF82-9F06-44B5-A8C41E89EDEA8101.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/9F2CD8E0-8D59-48DA-84A31B1400033505_source.jpg","image_width":440,"image_height":610,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"DgquxFGtuoNOdShgjhqJw","mura_id":null,"path":"/issue/sa/1973/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 228, Issue 2","volume":228,"issue":"2","issue_date":"1973-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/999F23DF-5C09-4854-B6BB4BFEC7E452BB.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/B4593A45-9CC4-44EC-89D5E7C9154EF9DD_source.jpg","image_width":440,"image_height":621,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"BiZSsajB4DSVnakwcs6FZ","mura_id":null,"path":"/issue/sa/1973/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 228, Issue 1","volume":228,"issue":"1","issue_date":"1973-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/03815079-FA24-4164-95DD11E9D64B78AA.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/CF6103FF-B08F-4B74-891AC0AA32CE758D_source.jpg","image_width":440,"image_height":603,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3SGucNZGNMxg2e0AmUS6Pc","mura_id":null,"path":"/issue/sa/1972/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 227, Issue 6","volume":227,"issue":"6","issue_date":"1972-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/664311B5-0A05-4D8D-9592BFC708B14D25.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/F075D4B5-3581-4B3E-A55FA18629E34CCE_source.jpg","image_width":440,"image_height":615,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1z208gkLzizonmsqDw1B12","mura_id":null,"path":"/issue/sa/1972/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 227, Issue 5","volume":227,"issue":"5","issue_date":"1972-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/26CDF5F4-246E-4B30-90A363F166F57D61.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/1EFE0A3D-74CE-4B82-AC97618E4E26C7D7_source.jpg","image_width":440,"image_height":604,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3GbRpoQYGvrwsZuKH8nj2R","mura_id":null,"path":"/issue/sa/1972/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 227, Issue 4","volume":227,"issue":"4","issue_date":"1972-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/EA5E0D8A-FFCF-49D8-BC399EF4E0911988.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/62DFF55F-2B15-4D77-8E3D91A151F95D62_source.jpg","image_width":440,"image_height":623,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4M01BKfHT2tVA9Kk4HMFul","mura_id":null,"path":"/issue/sa/1972/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 227, Issue 3","volume":227,"issue":"3","issue_date":"1972-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/38665374-6360-45C6-8B92C3D8A4FEC044.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/8AB73427-DC40-4B87-91A6EF2C502A9FEF_source.jpg","image_width":440,"image_height":614,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7x5y74quOsmfKkN4raCdOr","mura_id":null,"path":"/issue/sa/1972/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 227, Issue 2","volume":227,"issue":"2","issue_date":"1972-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/D7725A1C-A3E5-4608-900DA477FE78EB68.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/183530D3-CC72-4242-BBB2E5F50F432A8F_source.jpg","image_width":440,"image_height":614,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6aPEiNdY3vAO4yWarfiQzn","mura_id":null,"path":"/issue/sa/1972/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 227, Issue 1","volume":227,"issue":"1","issue_date":"1972-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8438FC36-75E7-4D6F-87AA488E2B109A1C.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/D0FFF27A-AC1D-4CF1-8B7499C7B7CA161F_source.jpg","image_width":440,"image_height":608,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"4i4XBv5U5vJUbDsEW0rAMF","mura_id":null,"path":"/issue/sa/1972/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 226, Issue 6","volume":226,"issue":"6","issue_date":"1972-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/9032C9E4-134B-43F2-AE64F1EFB2CF6B95.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/3DBD491D-3658-4771-9F8425920CF50709_source.jpg","image_width":440,"image_height":616,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"40tbcRquxHysWoLMWaxAuW","mura_id":null,"path":"/issue/sa/1972/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 226, Issue 5","volume":226,"issue":"5","issue_date":"1972-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/C94CE8AA-BC03-4896-A33800B1B70CECC5.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/8DAAC86F-1F44-41E0-B414745A9FD9A123_source.jpg","image_width":440,"image_height":618,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6Xb8JnfAJsqYRAzbbS04fC","mura_id":null,"path":"/issue/sa/1972/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 226, Issue 4","volume":226,"issue":"4","issue_date":"1972-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/C481961C-436E-4234-BC86B5E5A432F3BE.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/AFC2CC5C-F338-4641-A25CDBFF3CBC6CC3_source.jpg","image_width":440,"image_height":625,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"21lEtE61Fh1RgctAgiGZlX","mura_id":null,"path":"/issue/sa/1972/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 226, Issue 3","volume":226,"issue":"3","issue_date":"1972-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/B786333C-202B-4ECC-917BE1374836D498.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/814ED532-BED1-4975-96266718FF00FF86_source.jpg","image_width":440,"image_height":615,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"62IU9ioYr778aWOTgAX4Ca","mura_id":null,"path":"/issue/sa/1972/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 226, Issue 2","volume":226,"issue":"2","issue_date":"1972-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/12DBD02B-5227-462C-912952D6038DCA67.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/B4BB7BE4-997F-4A32-A774A59250B3915E_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5HffhSySYOzGCcLgHunoUn","mura_id":null,"path":"/issue/sa/1972/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 226, Issue 1","volume":226,"issue":"1","issue_date":"1972-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/E685CD15-1D95-4936-A17705DC58166BA4.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/34246B2E-B2A6-4DF2-AEA779D7CD1C72F3_source.jpg","image_width":440,"image_height":608,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"FUaE0JNekZFeIk3csH4Tz","mura_id":null,"path":"/issue/sa/1971/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 225, Issue 6","volume":225,"issue":"6","issue_date":"1971-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/28060529-312B-4102-92EA8824AB09B204.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/7FC0D681-AC61-47DB-9C4EA5F0CFBD186C_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6iXc7DjAS9zERl9ePu6xdS","mura_id":null,"path":"/issue/sa/1971/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 225, Issue 5","volume":225,"issue":"5","issue_date":"1971-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8637BE69-B99F-42DC-AC0B2C9062E372F2.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2022993C-CF1F-4580-B6D23A84CCCC2AB5_source.jpg","image_width":440,"image_height":598,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"J7pUVXdQM3LaxyUTy1FtZ","mura_id":null,"path":"/issue/sa/1971/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 225, Issue 4","volume":225,"issue":"4","issue_date":"1971-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/5A5F1268-EE4C-4B9C-AE338B325F6CFF18.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/A3AACF43-257B-40AE-B951A4809A4BB7A0_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"TESPqdutDOd4aWEwS7G9G","mura_id":null,"path":"/issue/sa/1971/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 225, Issue 3","volume":225,"issue":"3","issue_date":"1971-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/1C142EC5-D3F2-4C84-B3889B121AAD3155.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/A64EFC01-A138-4B58-90487E7A1C4B25B5_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"7xMyOYLqT8WIMoLkIBBdou","mura_id":null,"path":"/issue/sa/1971/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 225, Issue 2","volume":225,"issue":"2","issue_date":"1971-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/ADD34524-F4E4-40ED-8A4A70BE3660240E.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/201470A7-C773-4B80-ADD775C8D9BAD5FF_source.jpg","image_width":440,"image_height":613,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"5srepik3EAnhQWOZy8kRgf","mura_id":null,"path":"/issue/sa/1971/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 225, Issue 1","volume":225,"issue":"1","issue_date":"1971-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/5E4F934D-5F40-49C9-98706DF322553B13.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/02DFDBE1-52F7-4E98-AEAE1A287A74C2CC_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1RmEaPT9YfymRgyiGBjsdh","mura_id":null,"path":"/issue/sa/1971/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 224, Issue 6","volume":224,"issue":"6","issue_date":"1971-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/796A6178-1A45-4BA9-86FD4F9036F9C650.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/BD79C8ED-64EF-48EB-BA9C657240A5C9FC_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1AetX6jRbH7Yi3avwbbjcX","mura_id":null,"path":"/issue/sa/1971/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 224, Issue 5","volume":224,"issue":"5","issue_date":"1971-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/1E17D8AB-E7E6-4FE3-9F80A1C456C48DA8.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/0128F6B9-6317-461A-A16F15E11930895C_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"x9ratcQokDyvHTfgAVVWH","mura_id":null,"path":"/issue/sa/1971/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 224, Issue 4","volume":224,"issue":"4","issue_date":"1971-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/188F8EA8-9316-4B54-9069E73985FF3386.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2DE61568-D5B9-4BB1-8D041964473C52E4_source.jpg","image_width":440,"image_height":613,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"39TgME0WDMZttMuz4T07yP","mura_id":null,"path":"/issue/sa/1971/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 224, Issue 3","volume":224,"issue":"3","issue_date":"1971-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/31BD190B-1470-49A2-866960346DC3E335.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/461511BE-6985-483A-ACE26D5955710028_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1hJTRLFYA3zkvTT9L2JPq5","mura_id":null,"path":"/issue/sa/1971/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 224, Issue 2","volume":224,"issue":"2","issue_date":"1971-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8CBDD985-BA84-4D4B-8F833F368E48D495.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/2B7C0817-A989-4114-A8B94B86F7D23C73_source.jpg","image_width":440,"image_height":613,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"tMLc3gloUG3Xd3fOrC2jH","mura_id":null,"path":"/issue/sa/1971/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 224, Issue 1","volume":224,"issue":"1","issue_date":"1971-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/4704EA59-AAB1-483E-932845BCE70E6C86.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/C72EB130-DB58-464B-ADDC1E8ED8CE52E2_source.jpg","image_width":440,"image_height":604,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"AfVMc1AldNzyN4BZpY7iK","mura_id":null,"path":"/issue/sa/1970/12-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 223, Issue 6","volume":223,"issue":"6","issue_date":"1970-12-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/8F8F8259-8D15-4762-A6A542278C4B1FF7.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/60A23F1C-7CC6-450B-A88A4EBD47D1C3B7_source.jpg","image_width":440,"image_height":610,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2OA0HcYTURpbxH4Lzm2TWU","mura_id":null,"path":"/issue/sa/1970/11-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 223, Issue 5","volume":223,"issue":"5","issue_date":"1970-11-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/CD0C40F1-CA36-40FE-8216DFFD62BBB647.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/B53406CD-76AF-4783-A62688BD2F50185B_source.jpg","image_width":440,"image_height":607,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"e3tlYHZ0MxSq4BUcJBuKv","mura_id":null,"path":"/issue/sa/1970/10-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 223, Issue 4","volume":223,"issue":"4","issue_date":"1970-10-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/868064C1-379D-4992-9A60F4615C3D713F.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/E40FD568-6117-4C0C-A22BCBE8E7B17BF4_source.jpg","image_width":440,"image_height":621,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6YGbhfQAWdrl3A4N8Xmwab","mura_id":null,"path":"/issue/sa/1970/09-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 223, Issue 3","volume":223,"issue":"3","issue_date":"1970-09-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/5921FC65-D7DB-4200-9F436144B009723C.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/90806F89-25A5-4805-96905B202FA6A56A_source.jpg","image_width":440,"image_height":609,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3o0SvDqaG9Q0aMDZsBofU3","mura_id":null,"path":"/issue/sa/1970/08-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 223, Issue 2","volume":223,"issue":"2","issue_date":"1970-08-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/A7C5E72A-2437-478F-A5495702028BEEAE.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/C48F8C17-AEEC-4474-9F3CE5FF77635D11_source.jpg","image_width":440,"image_height":617,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"2TMAcVfZjDSrfgHTMLpyeP","mura_id":null,"path":"/issue/sa/1970/07-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 223, Issue 1","volume":223,"issue":"1","issue_date":"1970-07-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/CB3A39D9-6137-4601-8FEF15DCA36F63BE.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/899E5E34-7EC3-4A71-A16A31B16372C096_source.jpg","image_width":440,"image_height":599,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"60uXFpw9pOoFVDKH3xcju8","mura_id":null,"path":"/issue/sa/1970/06-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 222, Issue 6","volume":222,"issue":"6","issue_date":"1970-06-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/5C3F1664-DB33-4E17-A767888DD7D04B10.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/7AC365D2-DE44-49FD-B785B2969CC3E735_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"1jP7ReDfYrYWgzB0McD57l","mura_id":null,"path":"/issue/sa/1970/05-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 222, Issue 5","volume":222,"issue":"5","issue_date":"1970-05-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/9623533A-3F66-4F3D-B61FD05ADCF2B0F6.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/5A40CA3C-9300-4FA9-AAED46B0C758E9E3_source.jpg","image_width":440,"image_height":602,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"3t6JXaDNjMxITEMsMGDlfr","mura_id":null,"path":"/issue/sa/1970/04-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 222, Issue 4","volume":222,"issue":"4","issue_date":"1970-04-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/B1C1C8B2-870F-4839-A0B682F0700B8B9F.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/3F02F824-7BE8-4986-9139F51F4C81F55B_source.jpg","image_width":440,"image_height":599,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6Xm0wqJdRLWN1H5RP3m7AZ","mura_id":null,"path":"/issue/sa/1970/03-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 222, Issue 3","volume":222,"issue":"3","issue_date":"1970-03-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/2FE87015-B0DA-4CC3-89BCC64272FCD3CF.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/34340EC9-3475-4846-A8610AD17F681F0C_source.jpg","image_width":440,"image_height":605,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"6ISCUS1xdf31WO4zI5D9ml","mura_id":null,"path":"/issue/sa/1970/02-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 222, Issue 2","volume":222,"issue":"2","issue_date":"1970-02-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/85E91D3E-8BB5-4EDA-A93330BE96B2ECD7.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/27820B54-EADD-4ABE-81B4BE84002AE725_source.jpg","image_width":440,"image_height":608,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null},{"contentful_id":"47Yb4IGazFiH7G1QE2ocNg","mura_id":null,"path":"/issue/sa/1970/01-01/","magazine_title":"Scientific American Magazine","issue_title":"Scientific American Volume 222, Issue 1","volume":222,"issue":"1","issue_date":"1970-01-01","pdf_file":"https://static.scientificamerican.com/sciam/cache/file/70C12FDD-41A8-47B1-82D8867A5679BCAD.pdf","image_url":"https://static.scientificamerican.com/sciam/cache/file/AC67204D-B58E-467C-A1D6DFA0FDE7A799_source.jpg","image_width":440,"image_height":611,"image_alt_text":null,"image_caption":null,"image_credits":null,"cover_credits":null,"image_desktop_url":null,"image_desktop_width":0,"image_desktop_height":0,"image":null}],"startYear":1970,"endYear":1979,"meta":{"title":"Issue Archive: 1970-1979","canonicalUrl":"https://www.scientificamerican.com/archive/issues/1970s/","tags":{"description":"Browse Scientific American's archives going back to 1845","og:title":"Issue Archive: 1970-1979","og:description":"Browse Scientific American's archives going back to 1845"}},"dataLayerContent":{"content":{"articleDoi":"","authors":[],"authorsCategory":[],"canonicalUrl":"https://www.scientificamerican.com/archive/issues/1970s/","categories":"","collectionId":"","collectionName":"","column":"","containsMedia":"","contentId":"","contentDifficulty":"","contentModeling":[],"durability":"","editors":[],"isPartner":false,"isResalable":false,"isSyndicated":false,"journalIssueName":"","language":"en","partnerName":"","platform":"hopper","paywallExempt":null,"podcastSeries":"","primaryCategory":"","printDek":"","printTitle":"","publishedAtDate":"","publishedAtDateTime":"","publishedAtTime":"","sentiment":"","subCategory":"","title":"Issue Archive: 1970-1979","type":"archive","updatedAtDateTime":"","advertiser":"","campaign":"","isSponsored":false},"game":{"gameId":"","puzzleType":"","set":"","dek":""}},"abTestGroup":"3"},"bundle":"issues"}`)</script> <script data-layer="footer">;OptanonWrapper=()=>{};consentQueue=[];tp=[];pdl={requireConsent:'v2'};window.dataLayer=[];;window.__ads=[];_sf_async_config={};_cbq=[]</script> </body> </html>