Encyclopedia Britannica

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gtm-homepage-hero-banner-promo" href="https://premium.britannica.com/premium-membership/?utm_source=premium&utm_medium=homepage-hero&utm_campaign=black-friday-2024"> <picture style="display:flex;justify-content: center;width:100%;"> <source media="(min-width:1100px)" srcset="https://cdn.britannica.com/marketing/EB_BlackFridayDesktop_2200x200.png"> <source media="(min-width:780px)" srcset="https://cdn.britannica.com/marketing/EB_BlackFridayTablet_1560x200.png"> <img src="https://cdn.britannica.com/marketing/EB_BlackFridayMobile_720x100.png" alt=" Black Friday Sale 50% Off banner" style="object-fit: cover; width:100%;"> </picture> </a></DIV><div class="container"> <div class="kic-container qa-contentful1 my-20 "> <div class="label mb-10"> <a href="/on-this-day" > November 23, 2024 </a> </div> <div class="cards3up kic-grid-A1"> <div class="kic-title-container"> <h2 class="display-3 font-serif kic-title mb-15">Dueling Blockbusters</h2> <div class="font-serif"> Two much-anticipated films—one a sequel and the other a prequel—are set to be released this weekend. <a href="https://www.britannica.com/news/1324034/24f72b42f3ea8dc288a4a1cd6510edc0" class="md-crosslink " data-show-preview="true"><em>Gladiator II</em></a>, the follow-up to <a href="https://www.britannica.com/biography/Ridley-Scott" class="md-crosslink " data-show-preview="true">Ridley Scott</a>’s 2000 <a href="https://www.britannica.com/topic/Gladiator-film-by-Scott" class="md-crosslink " data-show-preview="true">blockbuster <em>Gladiator</em></a>, stars <a href="https://www.britannica.com/biography/Paul-Mescal" class="md-crosslink " data-show-preview="true">Paul Mescal</a> as <a href="https://www.britannica.com/place/ancient-Rome" class="md-crosslink " data-show-preview="true">Roman</a> emperor <a href="https://www.britannica.com/biography/Lucius-Verus" class="md-crosslink " data-show-preview="true">Lucius Verus</a> and <a href="https://www.britannica.com/biography/Pedro-Pascal" class="md-crosslink " data-show-preview="true">Pedro Pescal</a> as a military leader. Meanwhile, the first of two planned movies based on the musical <a href="https://www.britannica.com/topic/Wicked" class="md-crosslink " data-show-preview="true"><em>Wicked</em></a>—a prequel of <a href="https://www.britannica.com/topic/The-Wizard-of-Oz" class="md-crosslink " data-show-preview="true"><em>The Wizard of Oz</em></a>—will also <a href="https://www.britannica.com/news/1228261/8bc4f5778f8921ee48f75b64f9a80bba" class="md-crosslink " data-show-preview="true">be released this weekend</a>. It stars <a href="https://www.britannica.com/biography/Ariana-Grande" class="md-crosslink " data-show-preview="true">Ariana Grande</a> as Galinda and Cynthia Erivo as Elphaba. </div> </div> <div class="card-hero"> <div class="card "> <div class="card-media media-VIDEO"> <div data-type="video" class="position-relative w-100"> <img loading="eager" src="https://cdn.britannica.com/38/256638-138-FFB0A5AA/What-was-a-gladiator.jpg?w=727&h=410&c=crop&q=80" alt="What was a gladiator? History, explanation of professional combatants in ancient Rome." class="w-100" /> <div class="btn btn-link link-white position-absolute" style="left: 50%; top: 50%; transform: translate3d(-50%, -50%, 0)"> <em class="material-icons display-1" data-icon="play_circle_outline"></em> </div> <script type="application/json"> { "sources": [ { "file" : "//content.jwplatform.com/manifests/ikqPsNoL.m3u8" } ], "image": "https://cdn.britannica.com/38/256638-138-FFB0A5AA/What-was-a-gladiator.jpg", "tracks": [ { "file" : "//assets-jpcust.jwpsrv.com/tracks/V7UejumG.vtt", "label": "English" } ] } </script> </div> </div> <div class="card-body mt-10 p-0"> <a class="font-weight-bold h5" href="https://www.britannica.com/video/What-was-a-gladiator/-313878" target="_blank">The Not-So-Hollywood History of the Gladiator</a> <div class="credit mt-5" style="word-break: break-word;">Encyclopædia Britannica, Inc.</div> </div> </div> </div> <div class="card-2"> <div class="card card-horizontal card-sm-vertical"> <div class="card-media media-IMAGE"> <a class="position-relative w-100" href="/topic/Wicked"> <img loading="eager" src="https://cdn.britannica.com/41/264241-050-1E658A68/Cyntiha-Erivo-Ariana-Grande-Publicity-still-wicked-musical-movie-2024-Elphaba-Glenda.jpg?w=354&h=300&c=crop&q=80" alt="Publicity still of Cynthia Erivo, right, as Elphaba, and Ariana Grande, as Glenda, in a scene from the 2024 musical film Wicked directed by Jon M. Chu." class="w-100 " /> </a> </div> <div class="card-body mt-10 p-0"> <a class="font-weight-bold h5" href="/topic/Wicked">How <i>Wicked</i> Became a Broadway Sensation</a> <div class="credit mt-5" style="word-break: break-word;">© 2024 Marc Platt Productions/Universal Pictures</div> </div> </div> </div> <div class="card-3"> <div class="card card-horizontal card-sm-vertical"> <div class="card-media media-IMAGE"> <a class="position-relative w-100" href="/topic/The-Wonderful-Wizard-of-Oz"> <img loading="eager" src="https://cdn.britannica.com/45/236445-050-2823EC9F/Wicked-Witch-of-the-West-The-Wizard-of-Oz-1939.jpg?w=354&h=300&c=crop&q=80" alt="Publicity still of the Wicked Witch of the West (Margaret Hamilton) and one of the Flying Monkeys (Winged Monkeys) from the motion picture film "The Wizard of Oz" (1939); directed by Victor Fleming (there were a number of uncredited directors). (cinema, movies)" class="w-100 " /> </a> </div> <div class="card-body mt-10 p-0"> <a class="font-weight-bold h5" href="/topic/The-Wonderful-Wizard-of-Oz">Source Material: L. Frank Baum’s <i>The Wonderful Wizard of Oz</i></a> <div class="credit mt-5" style="word-break: break-word;">© 1939 Metro-Goldwyn-Mayer Inc.</div> </div> </div> </div> <div class="read-more"> <h3>Discover More</h3> <div class="grid"> <div class="col-sm-50 mb-15 mb-sm-0"> <a class="font-16 font-weight-bold" href="/quiz/match-the-quote-to-the-movie-quiz">Quiz: Can You Match the Quote to the Movie?</a> </div> <div class="col-sm-50 mb-15 mb-sm-0"> <a class="font-16 font-weight-bold" href="/sports/gladiator">The True Story of Ancient Rome’s Gladiators</a> </div> </div> </div> <div class="kic-right-rail kic-right-rail-A1 font-14"> <div class="feature-block "><div class="oyr-title-container"><h3 class="h2 oyr-title font-serif mb-15"> <a href="https://www.britannica.com/science/smog" class="md-crosslink " data-show-preview="true">An Ill Wind</a> </h3><p class="font-serif mb-20"><a href="https://www.britannica.com/place/India" class="md-crosslink " data-show-preview="true">India</a>’s most populous city is struggling under a blanket of smog, while a province in <a href="https://www.britannica.com/place/Pakistan" class="md-crosslink " data-show-preview="true">Pakistan</a> similarly imposes an emergency shutdown due to <a href="https://www.britannica.com/science/air-pollution" class="md-crosslink " data-show-preview="true">air pollution</a>.</p></div> <a class="oyr-link-title font-weight-bold d-block mb-10" href="/place/New-Delhi">Delhi</a><p class="font-serif mb-20">This week the smog in <a href="https://www.britannica.com/place/Delhi" class="md-crosslink " data-show-preview="true">Delhi</a>, India, reached <a href="https://www.britannica.com/news/1759701/ae1ec1e6292009db198f18b113047cd5" class="md-crosslink " data-show-preview="true">a seasonal high of 50 times the safe limit</a> set by the <a href="https://www.britannica.com/topic/World-Health-Organization" class="md-crosslink " data-show-preview="true">World Health Organization</a>. Authorities closed <a href="https://www.britannica.com/place/New-Delhi" class="md-crosslink " data-show-preview="true">New Delhi</a>’s schools, limited the amount of trucks on the road, and shut down construction work as residents reported headaches and sore throats. <a href="https://www.britannica.com/science/air-pollution" class="md-crosslink " data-show-preview="true">Air pollution</a> in the region usually rises in winter because of the burning of crops in agricultural areas—the lower temperatures cause smoke to stay in the air as it blows into cities and joins forces with urban pollutants.</p> <a class="oyr-link-title font-weight-bold d-block mb-10" href="/place/Punjab-province-Pakistan">Pakistan</a><p class="font-serif mb-20"><a href="https://www.britannica.com/news/550008/899d54e8b4474c2468cdf59d9aaf5225" class="md-crosslink " data-show-preview="true">A health emergency went into effect</a> throughout Pakistan’s <a href="https://www.britannica.com/place/Punjab-province-Pakistan" class="md-crosslink " data-show-preview="true">Punjab</a> province on November 15 as a heavy swath of <a href="https://www.britannica.com/science/smog" class="md-crosslink " data-show-preview="true">smog</a> continued to linger in the region. All schools and institutions were closed and a lockdown was imposed in Pakistan’s second largest city, <a href="https://www.britannica.com/place/Lahore" class="md-crosslink " data-show-preview="true">Lahore</a>—which has a population of more than 11 million—as well as <a href="https://www.britannica.com/place/Multan" class="md-crosslink " data-show-preview="true">Multan</a>. The smog, as in India, was partly due to crop burning, but auto emissions and pollution caused by construction and industrial work were also main culprits.</p> <a class="oyr-link-title font-weight-bold d-block mb-10" href="/science/smog">The two types of smog</a><p class="font-serif mb-20">The term <em>smog</em> is derived from the words <em>smoke</em> and <em>fog</em>, but not all smog is the same. There are two distinct types: sulfurous and photochemical. Sulfurous smog, also called “<a href="https://www.britannica.com/place/London" class="md-crosslink " data-show-preview="true">London</a> smog,” results from a high concentration of <a href="https://www.britannica.com/science/sulfur-oxide" class="md-crosslink " data-show-preview="true">sulfur oxides</a> in the air and is caused by the use of sulfur-bearing <a href="https://www.britannica.com/science/fossil-fuel" class="md-crosslink " data-show-preview="true">fossil fuels</a>, particularly <a href="https://www.britannica.com/science/coal-fossil-fuel" class="md-crosslink " data-show-preview="true">coal</a>. Photochemical smog, also known as “<a href="https://www.britannica.com/place/Los-Angeles-California" class="md-crosslink " data-show-preview="true">Los Angeles</a> smog,” occurs most prominently in urban areas that have large numbers of automobiles—and it requires neither smoke nor fog. It occurs when nitrogen oxides and <a href="https://www.britannica.com/science/hydrocarbon" class="md-crosslink " data-show-preview="true">hydrocarbon</a> vapor emissions undergo <a href="https://www.britannica.com/science/photochemical-reaction" class="md-crosslink " data-show-preview="true">photochemical reactions</a> in the lower <a href="https://www.britannica.com/science/atmosphere" class="md-crosslink " data-show-preview="true">atmosphere</a>. The highly toxic gas <a href="https://www.britannica.com/science/ozone" class="md-crosslink " data-show-preview="true">ozone</a> arises from this reaction, and some <a href="https://www.britannica.com/science/nitrogen-dioxide" class="md-crosslink " data-show-preview="true">nitrogen dioxide</a> is produced from the reaction of nitrogen oxide with sunlight.</p> </div> </div> </div> </div> </div> <div class="container trending-content my-40"> <h2 class="mb-15">Popular on <span>Britannica</span></h2> <div class="grid"> <div class="trending-list-container qa-treading-articles col-100 col-md-33 mb-30 mb-md-0"> <div class="Articles border-top-5"></div> <div class="border border-top-0 p-20 py-10 rounded-bl-lg rounded-br-lg"> <h3 class="font-16 text-uppercase mb-15 mb-md-20 d-block">Articles</h3> <ol class="list-none"> <li > <a class="d-block my-10 my-md-15" href="https://www.britannica.com/topic/War-and-Peace">War and Peace</a> </li> <li > <a class="d-block my-10 my-md-15" 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mb-20" > <div class="position-relative card-media" style="flex: 0;"> <a class="ilf-image position-relative" href="https://www.merriam-webster.com/games/blossom-word-game"> <img loading="lazy" src="https://cdn.britannica.com/kstm/GAME/blossom1x.jpeg?w=100&h=75&c=crop" alt="Blossom" width="100" height="75" /> </a> </div> <div class="card-body ilf-content"> <a class="font-weight-semi-bold d-block mb-5 font-16 ilf-title" href="https://www.merriam-webster.com/games/blossom-word-game" >Blossom</a> <div class="font-weight-light font-serif font-14 line-clamp clamp-2 ilf-description">Pick the best words</div> </div> </div> <div class="imagelink-with-image-on-the-side card card-horizontal mb-20" > <div class="position-relative card-media" style="flex: 0;"> <a class="ilf-image position-relative" href="https://www.britannica.com/games/octordle"> <img loading="lazy" src="https://cdn.britannica.com/kstm/GAME/octordle-4x3.png?w=100&h=75&c=crop" alt="Octordle" width="100" height="75" /> </a> </div> 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src="https://cdn.britannica.com/kstm/GAME/twofer-goofer.png?w=100&h=75&c=crop" alt="Twofer Goofer" width="100" height="75" /> </a> </div> <div class="card-body ilf-content"> <a class="font-weight-semi-bold d-block mb-5 font-16 ilf-title" href="https://www.merriam-webster.com/games/twofer-goofer" >Twofer Goofer</a> <div class="font-weight-light font-serif font-14 line-clamp clamp-2 ilf-description">Think you know it, poet?</div> </div> </div> <div class="imagelink-with-image-on-the-side card card-horizontal mb-20" > <div class="position-relative card-media" style="flex: 0;"> <a class="ilf-image position-relative" href="https://www.britannica.com/games/victordle/"> <img loading="lazy" src="https://cdn.britannica.com/kstm/GAME/victordle.png?w=100&h=75&c=crop" alt="Victordle" width="100" height="75" /> </a> </div> <div class="card-body ilf-content"> <a class="font-weight-semi-bold d-block mb-5 font-16 ilf-title" href="https://www.britannica.com/games/victordle/" >Victordle</a> <div 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