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class="vector-toc-list"> <li id="toc-What_is_a_pipehead_dam?" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#What_is_a_pipehead_dam?"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>What is a pipehead dam?</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">5 comments</span> <ul id="toc-What_is_a_pipehead_dam?-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>The higher the pitch of the instrument the longer the bow: why?</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">6 comments</span> <ul id="toc-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_13" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_13"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>November 13</span> </div> </a> <button aria-controls="toc-November_13-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 13 subsection</span> </button> <ul id="toc-November_13-sublist" class="vector-toc-list"> <li id="toc-Light_patterns" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Light_patterns"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Light patterns</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">3 comments</span> <ul id="toc-Light_patterns-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_14" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_14"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>November 14</span> </div> </a> <button aria-controls="toc-November_14-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 14 subsection</span> </button> <ul id="toc-November_14-sublist" class="vector-toc-list"> <li id="toc-Tau_propagation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Tau_propagation"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Tau propagation</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">2 comments</span> <ul id="toc-Tau_propagation-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_15" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_15"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>November 15</span> </div> </a> <button aria-controls="toc-November_15-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 15 subsection</span> </button> <ul id="toc-November_15-sublist" class="vector-toc-list"> <li id="toc-Why_are_Koalas_vulnerable_to_extinction" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Why_are_Koalas_vulnerable_to_extinction"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Why are Koalas vulnerable to extinction</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">6 comments</span> <ul id="toc-Why_are_Koalas_vulnerable_to_extinction-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Admiral_Nakhimov" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Admiral_Nakhimov"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Admiral Nakhimov</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">2 comments</span> <ul id="toc-Admiral_Nakhimov-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Why_don't_plants_photosynthesize_efficiently?" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Why_don't_plants_photosynthesize_efficiently?"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.3</span> <span>Why don't plants photosynthesize efficiently?</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">11 comments</span> <ul id="toc-Why_don't_plants_photosynthesize_efficiently?-sublist" class="vector-toc-list"> <li id="toc-What_about_near_volcanos?" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#What_about_near_volcanos?"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.3.1</span> <span>What about near volcanos?</span> </div> </a> <ul id="toc-What_about_near_volcanos?-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Thermometer_thermal_mass" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Thermometer_thermal_mass"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.4</span> <span>Thermometer thermal mass</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">6 comments</span> <ul id="toc-Thermometer_thermal_mass-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_17" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_17"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>November 17</span> </div> </a> <button aria-controls="toc-November_17-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 17 subsection</span> </button> <ul id="toc-November_17-sublist" class="vector-toc-list"> <li id="toc-A_lead_zeppelin_is_your_stairway_to_heaven?" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#A_lead_zeppelin_is_your_stairway_to_heaven?"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.1</span> <span>A lead zeppelin is your stairway to heaven?</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">13 comments</span> <ul id="toc-A_lead_zeppelin_is_your_stairway_to_heaven?-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Land_surveying" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Land_surveying"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.2</span> <span>Land surveying</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">11 comments</span> <ul id="toc-Land_surveying-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-How_sampling_rate_in_ADC_adjusted_or_set_?" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#How_sampling_rate_in_ADC_adjusted_or_set_?"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.3</span> <span>How sampling rate in ADC adjusted or set ?</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">6 comments</span> <ul id="toc-How_sampling_rate_in_ADC_adjusted_or_set_?-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_18" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_18"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>November 18</span> </div> </a> <button aria-controls="toc-November_18-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 18 subsection</span> </button> <ul id="toc-November_18-sublist" class="vector-toc-list"> <li id="toc-Open-air_dust_explosions" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Open-air_dust_explosions"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.1</span> <span>Open-air dust explosions</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">5 comments</span> <ul id="toc-Open-air_dust_explosions-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Delayed_onset_muscle_soreness" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Delayed_onset_muscle_soreness"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.2</span> <span>Delayed onset muscle soreness</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">4 comments</span> <ul id="toc-Delayed_onset_muscle_soreness-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_20" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_20"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>November 20</span> </div> </a> <button aria-controls="toc-November_20-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 20 subsection</span> </button> <ul id="toc-November_20-sublist" class="vector-toc-list"> <li id="toc-John_Balbus_and_Steven_Balbus" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#John_Balbus_and_Steven_Balbus"> <div class="vector-toc-text"> <span class="vector-toc-numb">8.1</span> <span>John Balbus and Steven Balbus</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">3 comments</span> <ul id="toc-John_Balbus_and_Steven_Balbus-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_21" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_21"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>November 21</span> </div> </a> <button aria-controls="toc-November_21-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 21 subsection</span> </button> <ul id="toc-November_21-sublist" class="vector-toc-list"> <li id="toc-Griffiths_in_math_and_physics" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Griffiths_in_math_and_physics"> <div class="vector-toc-text"> <span class="vector-toc-numb">9.1</span> <span>Griffiths in math and physics</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">9 comments</span> <ul id="toc-Griffiths_in_math_and_physics-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_22" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_22"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>November 22</span> </div> </a> <button aria-controls="toc-November_22-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 22 subsection</span> </button> <ul id="toc-November_22-sublist" class="vector-toc-list"> <li id="toc-Heat_of_chillies" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Heat_of_chillies"> <div class="vector-toc-text"> <span class="vector-toc-numb">10.1</span> <span>Heat of chillies</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">6 comments</span> <ul id="toc-Heat_of_chillies-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-November_23" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#November_23"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>November 23</span> </div> </a> <button aria-controls="toc-November_23-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle November 23 subsection</span> </button> <ul id="toc-November_23-sublist" class="vector-toc-list"> <li id="toc-Before_Puberty,_sex_organs_are_not_functional?" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Before_Puberty,_sex_organs_are_not_functional?"> <div class="vector-toc-text"> <span class="vector-toc-numb">11.1</span> <span>Before Puberty, sex organs are not functional?</span> </div> </a> <span class="ext-discussiontools-init-sidebar-meta">2 comments</span> <ul 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Do not edit others' comments and do not give any medical or legal advice.</li></ul> </div> <div class="rd-header">See also:</div> <ul class="rd-box"> <li><a href="/wiki/Wikipedia:Teahouse" title="Wikipedia:Teahouse">Teahouse</a></li> <li><a href="/wiki/Wikipedia:Help_desk" title="Wikipedia:Help desk">Help desk</a></li> <li><a href="/wiki/Wikipedia:Village_pump" title="Wikipedia:Village pump">Village pump</a></li> <li><a href="/wiki/Help:Contents" title="Help:Contents">Help manual</a></li> </ul> </div> <p><br/> </p><p><br/> </p> <meta property="mw:PageProp/toc"/> <div class="mw-heading mw-heading1"><h1 id="November_9" data-mw-thread-id="h-November_9-20241109231600"><span data-mw-comment-start="" id="h-November_9-20241109231600"></span>November 9<span data-mw-comment-end="h-November_9-20241109231600"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=1" title="Edit section: November 9"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Black_Body_emissive_power_in_medium" data-mw-thread-id="h-Black_Body_emissive_power_in_medium-November_9-20241109231600"><span data-mw-comment-start="" id="h-Black_Body_emissive_power_in_medium-November_9-20241109231600"></span>Black Body emissive power in medium<span data-mw-comment-end="h-Black_Body_emissive_power_in_medium-November_9-20241109231600"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=2" title="Edit section: Black Body emissive power in medium"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-Malypaet-20241109231600-Black_Body_emissive_power_in_medium"></span>The black body emissive power in a medium <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E_{m}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>m</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E_{m}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/3e2d5aa67bc4c46dfb5f6a1d674998ee81063a14" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.39ex; height:2.509ex;" alt="{\displaystyle E_{m}}"/></span> is equal to the product of the square of its refractive index <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle n}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>n</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle n}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a601995d55609f2d9f5e233e36fbe9ea26011b3b" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.395ex; height:1.676ex;" alt="{\displaystyle n}"/></span> and the emissive power in vacuum <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E_{v}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>v</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E_{v}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/449107507b1283251850665759926442312e9722" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.745ex; height:2.509ex;" alt="{\displaystyle E_{v}}"/></span> with the formula:<br/> <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E_{m}=n^{2}E_{v}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>m</mi> </mrow> </msub> <mo>=</mo> <msup> <mi>n</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>v</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E_{m}=n^{2}E_{v}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a9314203b5658b382164167f73878732f05e8937" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:11.683ex; height:3.009ex;" alt="{\displaystyle E_{m}=n^{2}E_{v}}"/></span>.<br/> What does this mean in terms of the energy emitted, respecting the principle of conservation of energy and in the case where the energy is emitted in a vacuum, then enters a medium with refractive index <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle n}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>n</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle n}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a601995d55609f2d9f5e233e36fbe9ea26011b3b" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.395ex; height:1.676ex;" alt="{\displaystyle n}"/></span>? <a href="/wiki/User:Malypaet" title="User:Malypaet">Malypaet</a> (<a href="/wiki/User_talk:Malypaet" title="User talk:Malypaet">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Malypaet-20241109231600-Black_Body_emissive_power_in_medium" class="ext-discussiontools-init-timestamplink">23:16, 9 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Malypaet-20241109231600-Black_Body_emissive_power_in_medium"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Malypaet-20241109231600-Black_Body_emissive_power_in_medium"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Graeme_Bartlett-20241111101500-Malypaet-20241109231600"></span>Power is energy emitted over time. So energy is conserved as it is emitted more slowly. Heat energy turns into electromagnetic energy. <a href="/wiki/User:Graeme_Bartlett" title="User:Graeme Bartlett">Graeme Bartlett</a> (<a href="/wiki/User_talk:Graeme_Bartlett" title="User talk:Graeme Bartlett">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Graeme_Bartlett-20241111101500-Malypaet-20241109231600" class="ext-discussiontools-init-timestamplink">10:15, 11 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Graeme_Bartlett-20241111101500-Malypaet-20241109231600"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Graeme_Bartlett-20241111101500-Malypaet-20241109231600"></span> <dl><dd><span data-mw-comment-start="" id="c-Malypaet-20241112233100-Graeme_Bartlett-20241111101500"></span>Yes, but here, if you use the SI units in <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle Joules\cdot s^{-1}\cdot sr^{-1}\cdot m^{-2}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>J</mi> <mi>o</mi> <mi>u</mi> <mi>l</mi> <mi>e</mi> <mi>s</mi> <mo>⋅</mo> <msup> <mi>s</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>1</mn> </mrow> </msup> <mo>⋅</mo> <mi>s</mi> <msup> <mi>r</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>1</mn> </mrow> </msup> <mo>⋅</mo> <msup> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>2</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle Joules\cdot s^{-1}\cdot sr^{-1}\cdot m^{-2}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/80418ef97fe5fd28cc0670412d71b7e422100399" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:24.102ex; height:2.676ex;" alt="{\displaystyle Joules\cdot s^{-1}\cdot sr^{-1}\cdot m^{-2}}"/></span> for emissive power as radiance, you have <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E_{m}>E_{v}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>m</mi> </mrow> </msub> <mo>></mo> <msub> <mi>E</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>v</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E_{m}>E_{v}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/1bce2d77aaef03ed38d8d497e5cc2c05c8bc94e9" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:9.234ex; height:2.509ex;" alt="{\displaystyle E_{m}>E_{v}}"/></span>. So, to conserve energy, you cannot use only the velocity for power, as you suggested. <a href="/wiki/User:Malypaet" title="User:Malypaet">Malypaet</a> (<a href="/wiki/User_talk:Malypaet" title="User talk:Malypaet">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Malypaet-20241112233100-Graeme_Bartlett-20241111101500" class="ext-discussiontools-init-timestamplink">23:31, 12 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Malypaet-20241112233100-Graeme_Bartlett-20241111101500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Malypaet-20241112233100-Graeme_Bartlett-20241111101500"></span> <dl><dd><span data-mw-comment-start="" id="c-176.3.66.65-20241122231400-Malypaet-20241112233100"></span>the most important unit is <i>sr</i> . In the vacuum the energy is distributed into all directions. In the medium it's too. But on entering the vacuum only certain directions are possible. In these directions the energy is concentrated. <a href="/wiki/Special:Contributions/176.3.66.65" title="Special:Contributions/176.3.66.65">176.3.66.65</a> (<a href="/w/index.php?title=User_talk:176.3.66.65&action=edit&redlink=1" class="new" title="User talk:176.3.66.65 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-176.3.66.65-20241122231400-Malypaet-20241112233100" class="ext-discussiontools-init-timestamplink">23:14, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-176.3.66.65-20241122231400-Malypaet-20241112233100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-176.3.66.65-20241122231400-Malypaet-20241112233100"></span></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_10" data-mw-thread-id="h-November_10-20241110010300"><span data-mw-comment-start="" id="h-November_10-20241110010300"></span>November 10<span data-mw-comment-end="h-November_10-20241110010300"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=3" title="Edit section: November 10"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="What_is_a_pipehead_dam?" data-mw-thread-id="h-What_is_a_pipehead_dam?-November_10-20241110010300"><span id="What_is_a_pipehead_dam.3F"></span><span data-mw-comment-start="" id="h-What_is_a_pipehead_dam?-November_10-20241110010300"></span>What is a <a href="/w/index.php?title=Pipehead_dam&action=edit&redlink=1" class="new" title="Pipehead dam (page does not exist)">pipehead dam</a>?<span data-mw-comment-end="h-What_is_a_pipehead_dam?-November_10-20241110010300"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=4" title="Edit section: What is a pipehead dam?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-Mitch_Ames-20241110010300-What_is_a_pipehead_dam?"></span>I've seen various things described as a "<a class="external text" href="https://en.wikipedia.org/w/index.php?search=pipehead+dam">pipehead dam</a>" (common noun), as well as some specific instances of dams named "... Pipehead Dam", eg <a href="/wiki/Serpentine_Pipehead_Dam" title="Serpentine Pipehead Dam">Serpentine Pipehead Dam</a>, which is separate to <a href="/wiki/Serpentine_Dam_(Western_Australia)" title="Serpentine Dam (Western Australia)">Serpentine Dam</a>. I gather from the text of <a href="/wiki/Serpentine_Pipehead_Dam" title="Serpentine Pipehead Dam">Serpentine Pipehead Dam</a> that a pipehead dam is a smaller dam fed from a larger dam, with the smaller (pipehead) dam then feeding water into the pipe into the water supply system - but I cannot find anything (including with a Google search) that specifically says that. <a href="/wiki/User:Mitch_Ames" title="User:Mitch Ames">Mitch Ames</a> (<a href="/wiki/User_talk:Mitch_Ames" title="User talk:Mitch Ames">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Mitch_Ames-20241110010300-What_is_a_pipehead_dam?" class="ext-discussiontools-init-timestamplink">01:03, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Mitch_Ames-20241110010300-What_is_a_pipehead_dam?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Mitch_Ames-20241110010300-What_is_a_pipehead_dam?"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Jpgordon-20241110012200-Mitch_Ames-20241110010300"></span>Wow! This was hard to hunt down. Deep in the results for probably the same set of searches you did, I finally found on page 77 of [<a rel="nofollow" class="external free" href="https://sitecore9-cm-prod.watercorporation.com.au/-/media/WaterCorp/Documents/Our-Water/Regional-Water-Supplies/water-forever-south-west-final-report.pdf">https://sitecore9-cm-prod.watercorporation.com.au/-/media/WaterCorp/Documents/Our-Water/Regional-Water-Supplies/water-forever-south-west-final-report.pdf</a>]: "Pipe-head dam — a diversion dam that takes streamflow</dd> <dd>from the catchment to another dam for storage." <a href="/wiki/User:Jpgordon" title="User:Jpgordon">--jpgordon</a><sup><small><a href="/wiki/User_talk:Jpgordon" title="User talk:Jpgordon">𝄢𝄆𝄐𝄇</a></small></sup> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Jpgordon-20241110012200-Mitch_Ames-20241110010300" class="ext-discussiontools-init-timestamplink">01:22, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Jpgordon-20241110012200-Mitch_Ames-20241110010300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Jpgordon-20241110012200-Mitch_Ames-20241110010300"></span> <dl><dd><span data-mw-comment-start="" id="c-Mitch_Ames-20241110100100-Jpgordon-20241110012200"></span>That definition appears to be the reverse of what the Serpentine articles say. The articles say water goes from main dam to pipehead dam, but the Water Corp definition suggest the water goes from pipehead to another (main?) dam. <a href="/wiki/User:Mitch_Ames" title="User:Mitch Ames">Mitch Ames</a> (<a href="/wiki/User_talk:Mitch_Ames" title="User talk:Mitch Ames">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Mitch_Ames-20241110100100-Jpgordon-20241110012200" class="ext-discussiontools-init-timestamplink">10:01, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Mitch_Ames-20241110100100-Jpgordon-20241110012200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Mitch_Ames-20241110100100-Jpgordon-20241110012200"></span> <dl><dd><span data-mw-comment-start="" id="c-JarrahTree-20241110105500-Mitch_Ames-20241110100100"></span>The point that might not necessarily come from the easy picking of the water authority or google online materials, is that in the history of the dams, the water can be moved either from the main dam to the pipehead, or vice versa - and in turn can also be distributed to other parts of the system, there is no <i>one way only</i> part of the system, maybe not easily found online but nevertheless the current water corp web space is very poor on the intracies of the dynamics of the water supply system. There could well be a range of security issues attached to the lack of information . <a href="/wiki/User:JarrahTree" title="User:JarrahTree">JarrahTree</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-JarrahTree-20241110105500-Mitch_Ames-20241110100100" class="ext-discussiontools-init-timestamplink">10:55, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-JarrahTree-20241110105500-Mitch_Ames-20241110100100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-JarrahTree-20241110105500-Mitch_Ames-20241110100100"></span> <dl><dd><span data-mw-comment-start="" id="c-Jpgordon-20241110163700-JarrahTree-20241110105500"></span>...for the over two centuries that pipe head dams have existed? <a href="/wiki/User:Jpgordon" title="User:Jpgordon">--jpgordon</a><sup><small><a href="/wiki/User_talk:Jpgordon" title="User talk:Jpgordon">𝄢𝄆𝄐𝄇</a></small></sup> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Jpgordon-20241110163700-JarrahTree-20241110105500" class="ext-discussiontools-init-timestamplink">16:37, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Jpgordon-20241110163700-JarrahTree-20241110105500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Jpgordon-20241110163700-JarrahTree-20241110105500"></span></dd></dl></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?" data-mw-thread-id="h-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?-November_10-20241110081500"><span id="The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why.3F"></span><span data-mw-comment-start="" id="h-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?-November_10-20241110081500"></span>The higher the pitch of the instrument the longer the bow: why?<span data-mw-comment-end="h-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?-November_10-20241110081500"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=5" title="Edit section: The higher the pitch of the instrument the longer the bow: why?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-178.51.16.158-20241110081500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"></span>As everyone has probably noticed, the violin has a longer bow than the viola, which has a longer bow than the cello, which has a longer bow than the double-bass. Why? I'm guessing a given length of bow (irrespective of the instrument) takes the string through a given number of vibrations. Therefore to make the string vibrate for a given amount of time at a higher frequency requires more bow length. But is this correct? Another consequence would be that no matter what the instrument the bows make the string vibrate for roughly the same amount of time and that the violin requires a higher bow speed than the viola which requires a higher bow speed than the cello which requires a higher bow speed than the double bass. Again, is this correct? <a href="/wiki/Special:Contributions/178.51.16.158" title="Special:Contributions/178.51.16.158">178.51.16.158</a> (<a href="/wiki/User_talk:178.51.16.158" title="User talk:178.51.16.158">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-178.51.16.158-20241110081500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?" class="ext-discussiontools-init-timestamplink">08:15, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-178.51.16.158-20241110081500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-178.51.16.158-20241110081500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241110091700-178.51.16.158-20241110081500"></span>To make the string vibrate with a nice sound, there has to be sufficient (but not too much) <a href="/wiki/Friction" title="Friction">friction</a> between the bow and the string, which requires the bow to move at the same speed or just slightly faster than the top speed of the vibrating string, 2<i>π</i> times the product of amplitude and frequency. So higher frequencies at a given level of <a href="/wiki/Dynamics_(music)" title="Dynamics (music)">dynamics</a> require a higher bow speed. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241110091700-178.51.16.158-20241110081500" class="ext-discussiontools-init-timestamplink">09:17, 10 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241110091700-178.51.16.158-20241110081500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241110091700-178.51.16.158-20241110081500"></span> <dl><dd><span data-mw-comment-start="" id="c-178.51.16.158-20241111171200-Lambiam-20241110091700"></span>Ok. But leaving aside variations of the amplitude of the vibration, of the tension of the string, of the tightness or looseness of the bow (which the player can adjust), of the mass of the string and of the bow, of the thickness of the string and of the material it is made of, of the thickness of the bow, of the length of the string, of the force exercised by the hand, of how carefully the player has rubbed his bow with rosin, of the quality of the rosin, etc. etc. is it nevertheless the case that (things being roughly equal) to sustain a string's vibration at a higher frequency for a given unit of time requires more bow length? Clearly in practice there wouldn't be a linear relation between increase in frequency and increase in length. <a href="/wiki/Special:Contributions/178.51.16.158" title="Special:Contributions/178.51.16.158">178.51.16.158</a> (<a href="/wiki/User_talk:178.51.16.158" title="User talk:178.51.16.158">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-178.51.16.158-20241111171200-Lambiam-20241110091700" class="ext-discussiontools-init-timestamplink">17:12, 11 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-178.51.16.158-20241111171200-Lambiam-20241110091700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-178.51.16.158-20241111171200-Lambiam-20241110091700"></span></dd></dl></dd></dl> <dl><dd><small><span data-mw-comment-start="" id="c-94.7.95.48-20241110175400-178.51.16.158-20241110081500"></span>(Only) slightly pertinent to this query, you might be amused by Kingsley Amis's 1971 novel <i><a href="/wiki/Girl,_20" title="Girl, 20">Girl, 20</a></i>, in which a would-be <i>avant-garde</i> classical composer and violinist performs a controversial concert with rock musicians (an actual thing at the time, see for example <a href="/wiki/Concerto_for_Group_and_Orchestra" title="Concerto for Group and Orchestra">Concerto for Group and Orchestra</a>). Someone has secretly greased both his violin bows, but he impresses with his technical skills (though not with his actual music) by borrowing and using a double-bass bow. {The poster formerly known as 87.81.230.195} <a href="/wiki/Special:Contributions/94.7.95.48" title="Special:Contributions/94.7.95.48">94.7.95.48</a> (<a href="/w/index.php?title=User_talk:94.7.95.48&action=edit&redlink=1" class="new" title="User talk:94.7.95.48 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-94.7.95.48-20241110175400-178.51.16.158-20241110081500" class="ext-discussiontools-init-timestamplink">17:54, 10 November 2024 (UTC)</a><span data-mw-comment-end="c-94.7.95.48-20241110175400-178.51.16.158-20241110081500"></span></small><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-94.7.95.48-20241110175400-178.51.16.158-20241110081500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span></dd></dl><p><span data-mw-comment-start="" id="c-Philvoids-20241111121500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"></span> The articles about <a href="/wiki/Bow_(music)" title="Bow (music)">Bow (music)</a> and the <a href="/wiki/Bow_maker" title="Bow maker"><i>archetien</i></a> who makes them say little about bow length. My survey below does not support the OP's observation. Lengthwise the bows for viola, violin and cello seem nearly interchangeable. The wide variation in longer bows for the double bass is due to the sitting players' preferences and arm lengths. </p><pre> | Viola | Violin | Cello | Double bass | | | | bow strings | | | | cm LOW TOP | | | | ----------------+--------+----------+---------+------------- 80 196 659 | GE | | | x 79 . . | | | | x 78 . . | | | | x 77 . . | | CA | | x 76 . . | | x | | x 75 . . | x | x | | x 74 . . | x | | CA | 73 . . | | | x | 72 41 98 | | | x | EG cm Hz Hz</pre> <p><a href="/w/index.php?title=User:Philvoids&action=edit&redlink=1" class="new" title="User:Philvoids (page does not exist)">Philvoids</a> (<a href="/wiki/User_talk:Philvoids" title="User talk:Philvoids">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Philvoids-20241111121500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?" class="ext-discussiontools-init-timestamplink">12:15, 11 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Philvoids-20241111121500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Philvoids-20241111121500-The_higher_the_pitch_of_the_instrument_the_longer_the_bow:_why?"></span> </p><dl><dd><span data-mw-comment-start="" id="c-94.7.95.48-20241111175300-Philvoids-20241111121500"></span>Your chart would make the relationships clearer if Violin were in the first column, reflecting the order of relative sizes (hence string lengths and usual ranges) of the instruments. I can see a clear correlation between increasing size and decreasing bow length for the first three instruments. The double-bass may be anomalous because, unlike the other three, it is usually played standing.</dd> <dd>I am also puzzled by your quoted figures, as my full-sized violin bow is only 65cm (ribbon length), and I am sure I have seen double-basses played with bows less than 50cm. {The poster formerly kown as 87.81.230.195} <a href="/wiki/Special:Contributions/94.7.95.48" title="Special:Contributions/94.7.95.48">94.7.95.48</a> (<a href="/w/index.php?title=User_talk:94.7.95.48&action=edit&redlink=1" class="new" title="User talk:94.7.95.48 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-94.7.95.48-20241111175300-Philvoids-20241111121500" class="ext-discussiontools-init-timestamplink">17:53, 11 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-94.7.95.48-20241111175300-Philvoids-20241111121500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-94.7.95.48-20241111175300-Philvoids-20241111121500"></span></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_13" data-mw-thread-id="h-November_13-20241113103800"><span data-mw-comment-start="" id="h-November_13-20241113103800"></span>November 13<span data-mw-comment-end="h-November_13-20241113103800"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=6" title="Edit section: November 13"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Light_patterns" data-mw-thread-id="h-Light_patterns-November_13-20241113103800"><span data-mw-comment-start="" id="h-Light_patterns-November_13-20241113103800"></span>Light patterns<span data-mw-comment-end="h-Light_patterns-November_13-20241113103800"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=7" title="Edit section: Light patterns"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-Panamitsu-20241113103800-Light_patterns"></span>When I stare at a ceiling light and use my fingers to very slowly close my eye lids I see a weird pattern emerge. It looks like <a href="/wiki/Floater" title="Floater">floaters</a> that are covering my entire vision. I must also add that you can also see it (but with lesser detail) if you position your phone so that you can see the sun's reflection in the camera, and then you bring the reflection right in front of an eye. </p><p>What am I seeing? I'm guessing it is something inside my eyes because it looks so much like floaters. ―<span style="font-family:Poppins, Helvetica, Sans-serif;"><a href="/wiki/User:Panamitsu" title="User:Panamitsu">Panamitsu</a></span> <a href="/wiki/User_talk:Panamitsu" title="User talk:Panamitsu">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Panamitsu-20241113103800-Light_patterns" class="ext-discussiontools-init-timestamplink">10:38, 13 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Panamitsu-20241113103800-Light_patterns"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Panamitsu-20241113103800-Light_patterns"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Baseball_Bugs-20241113133300-Panamitsu-20241113103800"></span>It sounds like you should ask your eye doctor. ←<a href="/wiki/User:Baseball_Bugs" title="User:Baseball Bugs">Baseball Bugs</a> <sup><i><a href="/wiki/User_talk:Baseball_Bugs" title="User talk:Baseball Bugs">What's up, Doc?</a></i></sup> <a href="/wiki/Special:Contributions/Baseball_Bugs" title="Special:Contributions/Baseball Bugs">carrots</a>→ <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Baseball_Bugs-20241113133300-Panamitsu-20241113103800" class="ext-discussiontools-init-timestamplink">13:33, 13 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Baseball_Bugs-20241113133300-Panamitsu-20241113103800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Baseball_Bugs-20241113133300-Panamitsu-20241113103800"></span></dd> <dd><span data-mw-comment-start="" id="c-Graeme_Bartlett-20241116100100-Panamitsu-20241113103800"></span>see also <a href="/wiki/Phosphene" title="Phosphene">Phosphene</a>. <a href="/wiki/User:Graeme_Bartlett" title="User:Graeme Bartlett">Graeme Bartlett</a> (<a href="/wiki/User_talk:Graeme_Bartlett" title="User talk:Graeme Bartlett">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Graeme_Bartlett-20241116100100-Panamitsu-20241113103800" class="ext-discussiontools-init-timestamplink">10:01, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Graeme_Bartlett-20241116100100-Panamitsu-20241113103800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Graeme_Bartlett-20241116100100-Panamitsu-20241113103800"></span></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_14" data-mw-thread-id="h-November_14-20241114201200"><span data-mw-comment-start="" id="h-November_14-20241114201200"></span>November 14<span data-mw-comment-end="h-November_14-20241114201200"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=8" title="Edit section: November 14"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Tau_propagation" data-mw-thread-id="h-Tau_propagation-November_14-20241114201200"><span data-mw-comment-start="" id="h-Tau_propagation-November_14-20241114201200"></span>Tau propagation<span data-mw-comment-end="h-Tau_propagation-November_14-20241114201200"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=9" title="Edit section: Tau propagation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-ExclusiveEditor-20241114201200-Tau_propagation"></span>Create redirect <a href="/w/index.php?title=Tau_propagation&action=edit&redlink=1" class="new" title="Tau propagation (page does not exist)">Tau propagation</a> to <s><a href="/wiki/Tau_protein#Tau_hypothesis_of_Alzheimer's_disease" title="Tau protein">Tau_protein#Tau hypothesis of Alzheimer's disease</a></s> which section of <a href="/wiki/Tau_protein" title="Tau protein">Tau protein</a>? <a href="/wiki/User:ExclusiveEditor" title="User:ExclusiveEditor"><span style="background:Orange;color:White;padding:2px;">Exclusive</span><span style="background:black; color:White; padding:2px;">Editor</span></a> <a href="/wiki/User_talk:ExclusiveEditor" title="User talk:ExclusiveEditor"><sub>Notify Me!</sub></a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-ExclusiveEditor-20241114201200-Tau_propagation" class="ext-discussiontools-init-timestamplink">20:12, 14 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-ExclusiveEditor-20241114201200-Tau_propagation"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-ExclusiveEditor-20241114201200-Tau_propagation"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241115053800-ExclusiveEditor-20241114201200"></span>It is a controversial hypothesis that cannot be dealt with with a simple redirect. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241115053800-ExclusiveEditor-20241114201200" class="ext-discussiontools-init-timestamplink">05:38, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241115053800-ExclusiveEditor-20241114201200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241115053800-ExclusiveEditor-20241114201200"></span></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_15" data-mw-thread-id="h-November_15-20241115042200"><span data-mw-comment-start="" id="h-November_15-20241115042200"></span>November 15<span data-mw-comment-end="h-November_15-20241115042200"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=10" title="Edit section: November 15"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Why_are_Koalas_vulnerable_to_extinction" data-mw-thread-id="h-Why_are_Koalas_vulnerable_to_extinction-November_15-20241115042200"><span data-mw-comment-start="" id="h-Why_are_Koalas_vulnerable_to_extinction-November_15-20241115042200"></span>Why are <a href="/wiki/Koala" title="Koala">Koalas</a> vulnerable to extinction<span data-mw-comment-end="h-Why_are_Koalas_vulnerable_to_extinction-November_15-20241115042200"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=11" title="Edit section: Why are Koalas vulnerable to extinction"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200-Why_are_Koalas_vulnerable_to_extinction"></span>Hi. I was wondering why Koalas are vulnerable to extinction unlike Kangaroos, which are way more common, and both animals are found in Australia. Please let me know. Thanks. <a href="/wiki/Special:Contributions/2605:B100:142:A3B7:1D63:4EBE:694C:7BCA" title="Special:Contributions/2605:B100:142:A3B7:1D63:4EBE:694C:7BCA">2605:B100:142:A3B7:1D63:4EBE:694C:7BCA</a> (<a href="/w/index.php?title=User_talk:2605:B100:142:A3B7:1D63:4EBE:694C:7BCA&action=edit&redlink=1" class="new" title="User talk:2605:B100:142:A3B7:1D63:4EBE:694C:7BCA (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200-Why_are_Koalas_vulnerable_to_extinction" class="ext-discussiontools-init-timestamplink">04:22, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200-Why_are_Koalas_vulnerable_to_extinction"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200-Why_are_Koalas_vulnerable_to_extinction"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Baseball_Bugs-20241115045400-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span>The article has some information on it. ←<a href="/wiki/User:Baseball_Bugs" title="User:Baseball Bugs">Baseball Bugs</a> <sup><i><a href="/wiki/User_talk:Baseball_Bugs" title="User talk:Baseball Bugs">What's up, Doc?</a></i></sup> <a href="/wiki/Special:Contributions/Baseball_Bugs" title="Special:Contributions/Baseball Bugs">carrots</a>→ <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Baseball_Bugs-20241115045400-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200" class="ext-discussiontools-init-timestamplink">04:54, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Baseball_Bugs-20241115045400-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Baseball_Bugs-20241115045400-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span></dd> <dd><span data-mw-comment-start="" id="c-Greglocock-20241115051700-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span>Habitat loss, especially lack of connected habitats, chlamidia, overcrowding, dogs. I doubt they are anywhere near extinct. <a href="/wiki/User:Greglocock" title="User:Greglocock">Greglocock</a> (<a href="/wiki/User_talk:Greglocock" title="User talk:Greglocock">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Greglocock-20241115051700-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200" class="ext-discussiontools-init-timestamplink">05:17, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Greglocock-20241115051700-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Greglocock-20241115051700-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span> <dl><dd><span data-mw-comment-start="" id="c-Alansplodge-20241115114400-Greglocock-20241115051700"></span>It might have been quicker to Google your question - this was one of the first results; <a rel="nofollow" class="external text" href="https://www.savethekoala.com/about-koalas/threats-to-the-koala/"><i>Threats To The Koala</i></a>. <a href="/wiki/User:Alansplodge" title="User:Alansplodge">Alansplodge</a> (<a href="/wiki/User_talk:Alansplodge" title="User talk:Alansplodge">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Alansplodge-20241115114400-Greglocock-20241115051700" class="ext-discussiontools-init-timestamplink">11:44, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Alansplodge-20241115114400-Greglocock-20241115051700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Alansplodge-20241115114400-Greglocock-20241115051700"></span></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-Graeme_Bartlett-20241115235200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span>Kangaroos are more flexible in what they eat, and can move large distances faster. But koalas are cuter and so have more public awareness and are used as the poster animal, like <a href="/wiki/Giant_panda" title="Giant panda">giant pandas</a>. <a href="/wiki/User:Graeme_Bartlett" title="User:Graeme Bartlett">Graeme Bartlett</a> (<a href="/wiki/User_talk:Graeme_Bartlett" title="User talk:Graeme Bartlett">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Graeme_Bartlett-20241115235200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200" class="ext-discussiontools-init-timestamplink">23:52, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Graeme_Bartlett-20241115235200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Graeme_Bartlett-20241115235200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span></dd> <dd><span data-mw-comment-start="" id="c-Wardog-20241119124200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span>More generally, the more specialised an organism is, the less likely it is to go extinct as a result of competition from other species but the more likely it is to be affected by environmental changes. So Koalas aren't going to have to worry about some other similar animal taking over its territory and taking all the eucalyptus for themselves. But they would be vulnerable to anything that killed off the eucalyptus. <a href="/wiki/User:Wardog" title="User:Wardog">Iapetus</a> (<a href="/wiki/User_talk:Wardog" title="User talk:Wardog">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Wardog-20241119124200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200" class="ext-discussiontools-init-timestamplink">12:42, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Wardog-20241119124200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Wardog-20241119124200-2605:B100:142:A3B7:1D63:4EBE:694C:7BCA-20241115042200"></span></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Admiral_Nakhimov" data-mw-thread-id="h-Admiral_Nakhimov-November_15-20241115145000"><span data-mw-comment-start="" id="h-Admiral_Nakhimov-November_15-20241115145000"></span>Admiral Nakhimov<span data-mw-comment-end="h-Admiral_Nakhimov-November_15-20241115145000"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=12" title="Edit section: Admiral Nakhimov"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000-Admiral_Nakhimov"></span>In the time leading up to <a href="/wiki/SS_Admiral_Nakhimov#Sinking" title="SS Admiral Nakhimov">the shipwreck in late August 1986</a>, is it known whether Captain Victor Tkachenko of the <i>Petr Vasev</i> had been transferred there from a smaller ship? Because I've read an article a while ago in <a href="/wiki/Science_et_Vie" class="mw-redirect" title="Science et Vie">Science et Vie</a> (the <a href="/wiki/Nauka_i_Zhizn" title="Nauka i Zhizn">Russian version</a>) about the human factors in that disaster, and this would be the only conclusion which would make any sense! <a href="/wiki/Special:Contributions/2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6" title="Special:Contributions/2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6">2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6</a> (<a href="/w/index.php?title=User_talk:2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6&action=edit&redlink=1" class="new" title="User talk:2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000-Admiral_Nakhimov" class="ext-discussiontools-init-timestamplink">14:50, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000-Admiral_Nakhimov"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000-Admiral_Nakhimov"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-ExclusiveEditor-20241116205600-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000"></span>I think the question is better suited at <a href="/wiki/Wikipedia:RDH" class="mw-redirect" title="Wikipedia:RDH">WP:RDH</a>. <a href="/wiki/User:ExclusiveEditor" title="User:ExclusiveEditor"><span style="background:Orange;color:White;padding:2px;">Exclusive</span><span style="background:black; color:White; padding:2px;">Editor</span></a> <a href="/wiki/User_talk:ExclusiveEditor" title="User talk:ExclusiveEditor"><sub>Notify Me!</sub></a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-ExclusiveEditor-20241116205600-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000" class="ext-discussiontools-init-timestamplink">20:56, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-ExclusiveEditor-20241116205600-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-ExclusiveEditor-20241116205600-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241115145000"></span></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Why_don't_plants_photosynthesize_efficiently?" data-mw-thread-id="h-Why_don't_plants_photosynthesize_efficiently?-November_15-20241115205400"><span id="Why_don.27t_plants_photosynthesize_efficiently.3F"></span><span data-mw-comment-start="" id="h-Why_don't_plants_photosynthesize_efficiently?-November_15-20241115205400"></span>Why don't plants photosynthesize efficiently?<span data-mw-comment-end="h-Why_don't_plants_photosynthesize_efficiently?-November_15-20241115205400"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=13" title="Edit section: Why don't plants photosynthesize efficiently?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><a href="/wiki/Photosynthesis" title="Photosynthesis"><span data-mw-comment-start="" id="c-Card_Zero-20241115205400-Why_don't_plants_photosynthesize_efficiently?"></span>Photosynthesis</a> is 6% efficient in green plants, 20% in solar panels. I see hints that it's more efficient in <a href="/wiki/Red_algae" title="Red algae">red algae</a>, but I can't find a figure. They need to be efficient because they live in low light environments. There's a note here at <a href="/wiki/Artificial_photosynthesis#Some_advantages,_disadvantages,_and_efficiency" title="Artificial photosynthesis">Artificial_photosynthesis#Some_advantages,_disadvantages,_and_efficiency</a> which says photosynthesis is typically 1% efficient! What's up with that? Something about not having enough CO2 around in the air to have any use for the energy? I found <a rel="nofollow" class="external text" href="https://www.quantamagazine.org/why-are-plants-green-to-reduce-the-noise-in-photosynthesis-20200730/">this article</a> which says <style data-mw-deduplicate="TemplateStyles:r1248585704">@media screen{html.skin-theme-clientpref-night .mw-parser-output .inline-quote-talk{color:#00B785}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .inline-quote-talk{color:#00B785}}.mw-parser-output .inline-quote-talk{font-family:Georgia,"DejaVu Serif",serif;color:#008560;quotes:none}.mw-parser-output .inline-quote-talk-italic{font-family:inherit;font-style:italic}.mw-parser-output .inline-quote-talk-marks{quotes:"\"""\""}</style><q class="inline-quote-talk">For the cell, a steady input of electrical energy coupled to a steady output of chemical energy is best: Too few electrons reaching the reaction center can cause an energy failure, while “too much energy will cause free radicals and all sorts of overcharging effects” that damage tissues</q>, but that seems to boil down to "the cells can't do it". <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241115205400-Why_don't_plants_photosynthesize_efficiently?" class="ext-discussiontools-init-timestamplink">20:54, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241115205400-Why_don't_plants_photosynthesize_efficiently?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241115205400-Why_don't_plants_photosynthesize_efficiently?"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Baseball_Bugs-20241115225500-Card_Zero-20241115205400"></span>Evolution doesn't necessarily aim for perfection, just for survival. If that 6 percent is good enough for survival, there would likely be no evolutionary pressure to do it "better". ←<a href="/wiki/User:Baseball_Bugs" title="User:Baseball Bugs">Baseball Bugs</a> <sup><i><a href="/wiki/User_talk:Baseball_Bugs" title="User talk:Baseball Bugs">What's up, Doc?</a></i></sup> <a href="/wiki/Special:Contributions/Baseball_Bugs" title="Special:Contributions/Baseball Bugs">carrots</a>→ <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Baseball_Bugs-20241115225500-Card_Zero-20241115205400" class="ext-discussiontools-init-timestamplink">22:55, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Baseball_Bugs-20241115225500-Card_Zero-20241115205400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Baseball_Bugs-20241115225500-Card_Zero-20241115205400"></span> <dl><dd><span data-mw-comment-start="" id="c-Card_Zero-20241115231500-Baseball_Bugs-20241115225500"></span>Trees compete for light, so there's some pressure to grow faster, isn't there? <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241115231500-Baseball_Bugs-20241115225500" class="ext-discussiontools-init-timestamplink">23:15, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241115231500-Baseball_Bugs-20241115225500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241115231500-Baseball_Bugs-20241115225500"></span></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-Graeme_Bartlett-20241115232300-Card_Zero-20241115205400"></span>If you want to compare solar panel effiency, you should compare production of a chemical like glucose from carbon dioxide using electricity. Or should we allow any other reduced and useful carbon compound. As plants do not just produce electricity. <a href="/wiki/User:Graeme_Bartlett" title="User:Graeme Bartlett">Graeme Bartlett</a> (<a href="/wiki/User_talk:Graeme_Bartlett" title="User talk:Graeme Bartlett">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Graeme_Bartlett-20241115232300-Card_Zero-20241115205400" class="ext-discussiontools-init-timestamplink">23:23, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Graeme_Bartlett-20241115232300-Card_Zero-20241115205400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Graeme_Bartlett-20241115232300-Card_Zero-20241115205400"></span></dd> <dd><span data-mw-comment-start="" id="c-176.2.78.14-20241116060200-Card_Zero-20241115205400"></span>Photosynthesis in plants can be very efficient under the right conditions. For instance, from photon to hydrogen/ATP it is nearly 100%,because the difference to really 100% is what destroys the chlorophyll. And replacing destroyed chlorophyll is costly, energywise and sometimes it even costs magnesium. Therefore that part is developed to maximize efficiency. Another goal is in the development of the carbon dioxide capture. For this one must know that chemical reactions with gases are very dependent on the pressure of the gases. Even the direction, that is if it's exothermic or endothermic, depends highly on the pressure. If RuBisCo would be faster the carbon dioxide could not come fast enough onto the site of enzymatic activity and would therefore drop in pressure there. Which in turn would drive the demand for energy up in this pathway. To overcome the RuBisCo-limit the C4 plants were developed. But they have other deficiencies, where they additionally spend energy to capture carbon dioxide for storage, and don't get it back at the RuBisCo.</dd> <dd>Generally plants have too much energy for the amount of water and, most important, carbon dioxide, to synthesize sugar. Some hydrogen has to be dumped into the production of <a href="/wiki/Ethen" title="Ethen">Ethen</a> and <a href="/wiki/Latex" title="Latex">Latex</a> or other hydrocarbons. Of course, the energy for this is typically not counted towards the efficiency of photosynthesis. Moreover some ATP is simply hydrolysed for heating. Or for regeneration of ADP. Whichever is needed where this takes place.</dd> <dd>For comparison there exist bacteria where chemical reactions are driven by 1/16th of a proton, that is 1/64 ATP-Unit. That only works with a large <a href="/wiki/Quantum_state" title="Quantum state">Quantum state</a> in a superposition. If someone would want to maximise the efficiency of the photosynthesis, the recipe is there for the taking. But think of the side effects! <a href="/wiki/Special:Contributions/176.2.78.14" title="Special:Contributions/176.2.78.14">176.2.78.14</a> (<a href="/w/index.php?title=User_talk:176.2.78.14&action=edit&redlink=1" class="new" title="User talk:176.2.78.14 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-176.2.78.14-20241116060200-Card_Zero-20241115205400" class="ext-discussiontools-init-timestamplink">06:02, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-176.2.78.14-20241116060200-Card_Zero-20241115205400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-176.2.78.14-20241116060200-Card_Zero-20241115205400"></span> <dl><dd><dl><dd><span data-mw-comment-start="" id="c-Avocado-20241116142100-176.2.78.14-20241116060200"></span>For this one must know that chemical reactions with gases are very dependent on the pressure of the gases. Even the direction, that is if it's exothermic or endothermic, depends highly on the pressure. If RuBisCo would be faster the carbon dioxide could not come fast enough onto the site of enzymatic activity and would therefore drop in pressure there.</dd></dl></dd> <dd>Does this mean that plants photosynthesize more efficiently in environments with elevated air pressure? Can you recommend any resources for learning more about that? Thank you! -- <a href="/wiki/User:Avocado" title="User:Avocado">Avocado</a> (<a href="/wiki/User_talk:Avocado" title="User talk:Avocado">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Avocado-20241116142100-176.2.78.14-20241116060200" class="ext-discussiontools-init-timestamplink">14:21, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Avocado-20241116142100-176.2.78.14-20241116060200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Avocado-20241116142100-176.2.78.14-20241116060200"></span> <dl><dd><span data-mw-comment-start="" id="c-Michael_D._Turnbull-20241120125700-Avocado-20241116142100"></span>@<a href="/wiki/User:Avocado" title="User:Avocado">Avocado</a> Not air pressure but partial pressure of carbon dioxide. That's standard in greenhouses. See <a href="/wiki/Greenhouse#Carbon_dioxide_enrichment" title="Greenhouse">Greenhouse#Carbon dioxide enrichment</a> for details. <a href="/wiki/User:Michael_D._Turnbull" title="User:Michael D. Turnbull">Mike Turnbull</a> (<a href="/wiki/User_talk:Michael_D._Turnbull" title="User talk:Michael D. Turnbull">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Michael_D._Turnbull-20241120125700-Avocado-20241116142100" class="ext-discussiontools-init-timestamplink">12:57, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Michael_D._Turnbull-20241120125700-Avocado-20241116142100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Michael_D._Turnbull-20241120125700-Avocado-20241116142100"></span> <dl><dd><span data-mw-comment-start="" id="c-Avocado-20241120210200-Michael_D._Turnbull-20241120125700"></span>Thank you! Is there any research about elevated air pressure, too? IIRC, humans absorb oxygen more efficiently at higher air pressures (up to a point), so it seems like it might make sense (based on both that and what little I know about gas exchange across membranes) for plants to absorb CO2 better at higher air pressures as well. -- <a href="/wiki/User:Avocado" title="User:Avocado">Avocado</a> (<a href="/wiki/User_talk:Avocado" title="User talk:Avocado">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Avocado-20241120210200-Michael_D._Turnbull-20241120125700" class="ext-discussiontools-init-timestamplink">21:02, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Avocado-20241120210200-Michael_D._Turnbull-20241120125700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Avocado-20241120210200-Michael_D._Turnbull-20241120125700"></span> <dl><dd><span data-mw-comment-start="" id="c-176.3.66.65-20241122230400-Avocado-20241120210200"></span>humans are developed to an oxygen pressure of 0,22 atm. Over it there are many reactions that disturb the physiology, under it there is to over 0,17 atm no difference as long as no (not the least amount) <a href="/wiki/Carbon_monoxide" title="Carbon monoxide">Carbon monoxide</a> comes into play. But even 0,11 atm is sufficient for up to 2 hours. At this low pressure of oxygen no normal combustion is possible but nobody needs an oxygen mask immediately. In case of a fire that is a great advantage for fire fighting. <a href="/wiki/Special:Contributions/176.3.66.65" title="Special:Contributions/176.3.66.65">176.3.66.65</a> (<a href="/w/index.php?title=User_talk:176.3.66.65&action=edit&redlink=1" class="new" title="User talk:176.3.66.65 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-176.3.66.65-20241122230400-Avocado-20241120210200" class="ext-discussiontools-init-timestamplink">23:04, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-176.3.66.65-20241122230400-Avocado-20241120210200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-176.3.66.65-20241122230400-Avocado-20241120210200"></span></dd></dl></dd></dl></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading3"><h3 id="What_about_near_volcanos?" data-mw-thread-id="h-What_about_near_volcanos?-Why_don't_plants_photosynthesize_efficiently?-20241116124200"><span id="What_about_near_volcanos.3F"></span><span data-mw-comment-start="" id="h-What_about_near_volcanos?-Why_don't_plants_photosynthesize_efficiently?-20241116124200"></span>What about near volcanos?<span data-mw-comment-end="h-What_about_near_volcanos?-Why_don't_plants_photosynthesize_efficiently?-20241116124200"></span></h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=14" title="Edit section: What about near volcanos?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><span data-mw-comment-start="" id="c-Card_Zero-20241116124200-What_about_near_volcanos?"></span>Are there specialized plants growing in carbon dioxide rich environments that photosynthesize faster? <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241116124200-What_about_near_volcanos?" class="ext-discussiontools-init-timestamplink">12:42, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241116124200-What_about_near_volcanos?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241116124200-What_about_near_volcanos?"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Abductive-20241116210700-Card_Zero-20241116124200"></span>No. I heard there are only a few places where there is consistent outgassing of CO<sub>2</sub> and yes, plants grow faster there. The thing is, plants are so starved for CO<sub>2</sub> that increasing CO<sub>2</sub> concentration instantaneously leads to increased sugar production. We think that the current photosynthesis evolved in a time when the atmosphere was like Venus's with perhaps 100 times the partial pressure of CO<sub>2</sub>. Even now, you can put a houseplant in a pure CO<sub>2</sub> atmosphere in a glass vessel, and it does great. Another way of putting this is that there can be no natural selection for specialization in growing in a "carbon dioxide rich environment" since that would entail getting <i>worse</i> at using CO<sub>2</sub>. <span style="font-family: Cambria;"> <a href="/wiki/User:Abductive" title="User:Abductive"><span style="color: teal;"><b>Abductive</b></span></a> (<a href="/wiki/User_talk:Abductive" title="User talk:Abductive">reasoning</a>)</span> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Abductive-20241116210700-Card_Zero-20241116124200" class="ext-discussiontools-init-timestamplink">21:07, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Abductive-20241116210700-Card_Zero-20241116124200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Abductive-20241116210700-Card_Zero-20241116124200"></span></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Thermometer_thermal_mass" data-mw-thread-id="h-Thermometer_thermal_mass-November_15-20241115221200"><span data-mw-comment-start="" id="h-Thermometer_thermal_mass-November_15-20241115221200"></span>Thermometer thermal mass<span data-mw-comment-end="h-Thermometer_thermal_mass-November_15-20241115221200"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=15" title="Edit section: Thermometer thermal mass"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-2601:644:8581:75B0:0:0:0:2CDE-20241115221200-Thermometer_thermal_mass"></span>I'd like to measure the air temperature in a room, outdoors, etc. Ideally by bringing the thermometer, turning it on if it is electronic, and looking at it. All thermometers that I've tried take several minutes to settle, which is annoyingly long. Is that inherent? Are there quicker ones? Don't want to spend a fortune, but "premium" is ok. Thanks. <a href="/wiki/Special:Contributions/2601:644:8581:75B0:0:0:0:2CDE" title="Special:Contributions/2601:644:8581:75B0:0:0:0:2CDE">2601:644:8581:75B0:0:0:0:2CDE</a> (<a href="/wiki/User_talk:2601:644:8581:75B0:0:0:0:2CDE" title="User talk:2601:644:8581:75B0:0:0:0:2CDE">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-2601:644:8581:75B0:0:0:0:2CDE-20241115221200-Thermometer_thermal_mass" class="ext-discussiontools-init-timestamplink">22:12, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-2601:644:8581:75B0:0:0:0:2CDE-20241115221200-Thermometer_thermal_mass"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-2601:644:8581:75B0:0:0:0:2CDE-20241115221200-Thermometer_thermal_mass"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Graeme_Bartlett-20241115234500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200"></span>For an expensive high-tech solution use <a href="/wiki/Tunable_diode_laser_absorption_spectroscopy" title="Tunable diode laser absorption spectroscopy">tunable diode laser absorption spectroscopy</a> which should measure the temperature in the gas, rather than waiting for it to conduct into a detector. see <a rel="nofollow" class="external free" href="https://www.yokogawa.com/solutions/products-and-services/measurement/analyzers/gas-analyzers/tunable-diode-laser-spectrometer/#Overview">https://www.yokogawa.com/solutions/products-and-services/measurement/analyzers/gas-analyzers/tunable-diode-laser-spectrometer/#Overview</a> for a product. <a href="/wiki/User:Graeme_Bartlett" title="User:Graeme Bartlett">Graeme Bartlett</a> (<a href="/wiki/User_talk:Graeme_Bartlett" title="User talk:Graeme Bartlett">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Graeme_Bartlett-20241115234500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200" class="ext-discussiontools-init-timestamplink">23:45, 15 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Graeme_Bartlett-20241115234500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Graeme_Bartlett-20241115234500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200"></span> <dl><dd><span data-mw-comment-start="" id="c-176.2.78.14-20241116013600-Graeme_Bartlett-20241115234500"></span>a really cheap way to go at it would be <a href="/wiki/Resistance_thermometer#Coiled_elements" title="Resistance thermometer">Resistance thermometer</a> of course in <a href="/wiki/Resistance_thermometer#Four-wire_configuration" title="Resistance thermometer">Four-wire configuration</a>. If the coil is very short, which is possible in four wires, then it will get the temperature in under a second. <a href="/wiki/Special:Contributions/176.2.78.14" title="Special:Contributions/176.2.78.14">176.2.78.14</a> (<a href="/w/index.php?title=User_talk:176.2.78.14&action=edit&redlink=1" class="new" title="User talk:176.2.78.14 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-176.2.78.14-20241116013600-Graeme_Bartlett-20241115234500" class="ext-discussiontools-init-timestamplink">01:36, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-176.2.78.14-20241116013600-Graeme_Bartlett-20241115234500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-176.2.78.14-20241116013600-Graeme_Bartlett-20241115234500"></span></dd> <dd><span data-mw-comment-start="" id="c-2601:644:8581:75B0:0:0:0:2CDE-20241116024500-Graeme_Bartlett-20241115234500"></span>Thanks both, the resistance thermometer approach sounds promising. The tunable laser page says "request a quote" which means "too expensive for me to think about". <a href="/wiki/Special:Contributions/2601:644:8581:75B0:0:0:0:2CDE" title="Special:Contributions/2601:644:8581:75B0:0:0:0:2CDE">2601:644:8581:75B0:0:0:0:2CDE</a> (<a href="/wiki/User_talk:2601:644:8581:75B0:0:0:0:2CDE" title="User talk:2601:644:8581:75B0:0:0:0:2CDE">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-2601:644:8581:75B0:0:0:0:2CDE-20241116024500-Graeme_Bartlett-20241115234500" class="ext-discussiontools-init-timestamplink">02:45, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-2601:644:8581:75B0:0:0:0:2CDE-20241116024500-Graeme_Bartlett-20241115234500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-2601:644:8581:75B0:0:0:0:2CDE-20241116024500-Graeme_Bartlett-20241115234500"></span></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-85.76.117.61-20241116154500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200"></span>An <a href="/wiki/Infrared_thermometer" title="Infrared thermometer">infrared thermometer</a> retails at around USD 10, and reacts in less than a second from when you press the button. It doesn't measure air temperature but if you can assume your walls/floors/furniture/etc are about the same temp, it'll work. <a href="/wiki/Special:Contributions/85.76.117.61" title="Special:Contributions/85.76.117.61">85.76.117.61</a> (<a href="/wiki/User_talk:85.76.117.61" title="User talk:85.76.117.61">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-85.76.117.61-20241116154500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200" class="ext-discussiontools-init-timestamplink">15:45, 16 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-85.76.117.61-20241116154500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-85.76.117.61-20241116154500-2601:644:8581:75B0:0:0:0:2CDE-20241115221200"></span> <dl><dd><span data-mw-comment-start="" id="c-2601:644:8581:75B0:0:0:0:2CDE-20241117021300-85.76.117.61-20241116154500"></span>I have one but it is not very consistent between surfaces, and the air temperature can change faster than the furniture temperature. I guess it is better than nothing. Thanks. <a href="/wiki/Special:Contributions/2601:644:8581:75B0:0:0:0:2CDE" title="Special:Contributions/2601:644:8581:75B0:0:0:0:2CDE">2601:644:8581:75B0:0:0:0:2CDE</a> (<a href="/wiki/User_talk:2601:644:8581:75B0:0:0:0:2CDE" title="User talk:2601:644:8581:75B0:0:0:0:2CDE">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-2601:644:8581:75B0:0:0:0:2CDE-20241117021300-85.76.117.61-20241116154500" class="ext-discussiontools-init-timestamplink">02:13, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-2601:644:8581:75B0:0:0:0:2CDE-20241117021300-85.76.117.61-20241116154500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-2601:644:8581:75B0:0:0:0:2CDE-20241117021300-85.76.117.61-20241116154500"></span></dd></dl></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_17" data-mw-thread-id="h-November_17-20241117034100"><span data-mw-comment-start="" id="h-November_17-20241117034100"></span>November 17<span data-mw-comment-end="h-November_17-20241117034100"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=16" title="Edit section: November 17"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="A_lead_zeppelin_is_your_stairway_to_heaven?" data-mw-thread-id="h-A_lead_zeppelin_is_your_stairway_to_heaven?-November_17-20241117034100"><span id="A_lead_zeppelin_is_your_stairway_to_heaven.3F"></span><span data-mw-comment-start="" id="h-A_lead_zeppelin_is_your_stairway_to_heaven?-November_17-20241117034100"></span>A <a href="/wiki/Lead_zeppelin" class="mw-redirect" title="Lead zeppelin">lead zeppelin</a> is your <a href="/wiki/Stairway_to_heaven" class="mw-redirect" title="Stairway to heaven">stairway to heaven</a>?<span data-mw-comment-end="h-A_lead_zeppelin_is_your_stairway_to_heaven?-November_17-20241117034100"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=17" title="Edit section: A lead zeppelin is your stairway to heaven?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100-A_lead_zeppelin_is_your_stairway_to_heaven?"></span>In terms of fatalities per <a href="/wiki/Passenger-mile" class="mw-redirect" title="Passenger-mile">passenger-mile</a>, and excluding combat losses during <a href="/wiki/World_War_1" class="mw-redirect" title="World War 1">World War 1</a> (but including accidental losses during the same time period), which <a href="/wiki/Airships" class="mw-redirect" title="Airships">airships</a> were more dangerous to fly in, those filled with <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a> or with <a href="/wiki/Helium" title="Helium">helium</a>? I'm aware of the argument that helium-filled airships have a narrower <a href="/wiki/Flight_envelope" title="Flight envelope">flight envelope</a>, which causes them <a href="/wiki/USS_Shenandoah" title="USS Shenandoah">to crash</a> <a href="/wiki/USS_Akron" title="USS Akron">more often</a> -- but, on the other hand, the flammability of hydrogen often had the effect of turning an otherwise survivable crash into <a href="/wiki/R-101" class="mw-redirect" title="R-101">one which is fatal for everyone on board</a>, and also created the danger of <a href="/wiki/Dixmude_(airship)" title="Dixmude (airship)">explosion from lightning strike</a> -- so between these two dangers, which one was the greatest? <a href="/wiki/Special:Contributions/2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6" title="Special:Contributions/2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6">2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6</a> (<a href="/w/index.php?title=User_talk:2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6&action=edit&redlink=1" class="new" title="User talk:2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100-A_lead_zeppelin_is_your_stairway_to_heaven?" class="ext-discussiontools-init-timestamplink">03:41, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100-A_lead_zeppelin_is_your_stairway_to_heaven?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100-A_lead_zeppelin_is_your_stairway_to_heaven?"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241117084800-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"></span>Is there a source for the claimed explosion? It is not plausible, scientifically. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241117084800-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100" class="ext-discussiontools-init-timestamplink">08:48, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241117084800-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241117084800-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"></span> <dl><dd><span data-mw-comment-start="" id="c-Card_Zero-20241117093900-Lambiam-20241117084800"></span>In what way not plausible? If your objection is to do with needing oxygen, that airship probably leaked: six months previously, "many small tears appeared". <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241117093900-Lambiam-20241117084800" class="ext-discussiontools-init-timestamplink">09:39, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241117093900-Lambiam-20241117084800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241117093900-Lambiam-20241117084800"></span> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241117101600-Card_Zero-20241117093900"></span>It would leak hydrogen out, not oxygen in. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241117101600-Card_Zero-20241117093900" class="ext-discussiontools-init-timestamplink">10:16, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241117101600-Card_Zero-20241117093900"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241117101600-Card_Zero-20241117093900"></span> <dl><dd><span data-mw-comment-start="" id="c-Card_Zero-20241117105200-Lambiam-20241117101600"></span>So if a leak of hydrogen into air is hit by lightning, on top of a balloon made from sausage skin that's filled with more hydrogen, how do you imagine events would unfold after that? <a href="/wiki/Hindenburg_disaster#Lightning_hypothesis" title="Hindenburg disaster">Hindenburg_disaster#Lightning_hypothesis</a> says that <i>airship fires have been observed</i> under these kind of circumstances. I'm surprised that they were only fires, it makes the outcome sound mild, like lighting a gas stove. <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241117105200-Lambiam-20241117101600" class="ext-discussiontools-init-timestamplink">10:52, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241117105200-Lambiam-20241117101600"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241117105200-Lambiam-20241117101600"></span> <dl><dd><span data-mw-comment-start="" id="c-PiusImpavidus-20241117140000-Card_Zero-20241117105200"></span>If there's a leak in the gas bags, it's plausible you may get an explosive mixture in the space between the gas bags and the outer hull. What exactly happened to Dixmude may never be known, but whether it was an explosion or rapid burning, too rapid for an orderly emergency landing (Hindenburg burned all its lifting gas in about half a minute), doesn't matter; all on board would be dead anyway. <a href="/wiki/User:PiusImpavidus" title="User:PiusImpavidus">PiusImpavidus</a> (<a href="/wiki/User_talk:PiusImpavidus" title="User talk:PiusImpavidus">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-PiusImpavidus-20241117140000-Card_Zero-20241117105200" class="ext-discussiontools-init-timestamplink">14:00, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-PiusImpavidus-20241117140000-Card_Zero-20241117105200"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-PiusImpavidus-20241117140000-Card_Zero-20241117105200"></span> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241117164600-PiusImpavidus-20241117140000"></span>That would indeed explain it. Without prior mixing with oxygen-containing air, hydrogen burns fiercely in a rapidly advancing front, as seen in the Hindenburg disaster, but not so rapid that there is an explosion. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241117164600-PiusImpavidus-20241117140000" class="ext-discussiontools-init-timestamplink">16:46, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241117164600-PiusImpavidus-20241117140000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241117164600-PiusImpavidus-20241117140000"></span></dd></dl></dd></dl></dd></dl></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-Lambiam-20241117103000-Lambiam-20241117084800"></span>I found <a rel="nofollow" class="external text" href="https://books.google.com/books?id=HHw6AQAAIAAJ&dq=%22the+Dixmude+had+exploded+with+great+violence%22&hl=en">a source</a>, but no explanation. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241117103000-Lambiam-20241117084800" class="ext-discussiontools-init-timestamplink">10:30, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241117103000-Lambiam-20241117084800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241117103000-Lambiam-20241117084800"></span> <dl><dd><span data-mw-comment-start="" id="c-Sean.hoyland-20241117103800-Lambiam-20241117103000"></span>According to the footnote in <a rel="nofollow" class="external text" href="https://www.theguardian.com/theguardian/2010/dec/29/archive-dixmude-airship-disaster-1923">this</a> republished 1923 article, there was an inquiry in January 1924, so maybe there is a report out there somewhere. <a href="/wiki/User:Sean.hoyland" title="User:Sean.hoyland">Sean.hoyland</a> (<a href="/wiki/User_talk:Sean.hoyland" title="User talk:Sean.hoyland">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Sean.hoyland-20241117103800-Lambiam-20241117103000" class="ext-discussiontools-init-timestamplink">10:38, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Sean.hoyland-20241117103800-Lambiam-20241117103000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Sean.hoyland-20241117103800-Lambiam-20241117103000"></span></dd></dl></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-PiusImpavidus-20241117165000-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"></span>This is hard to say...</dd> <dd>A helium-filled airship has less lift for the same volume, so it has to compensate somehow: fewer passengers and passenger-kilometres, giving more accidents per passenger-kilometre, or lighter skin, frame or engines or less fuel, all increasing accident rate.</dd> <dd>A helium-filled airship is less likely to burn. The hydrogen fire itself isn't very lethal (except for those sitting high up in the envelope), but it can accelerate the destruction of the airship, leading to a faster crash, and set the skin and fuel on fire, leaving burning wreckage, which can kill passengers.</dd> <dd>A third effect, which you didn't mention, is the <a href="/wiki/Heat_capacity_ratio" title="Heat capacity ratio">heat capacity ratio</a>. Helium has a heat capacity ratio of 1.66, hydrogen of 1.41, just like dry air, and moist air has an even lower heat capacity ratio. This means that on descent, helium heats up by <a href="/wiki/Adiabatic_compression" class="mw-redirect" title="Adiabatic compression">adiabatic compression</a> faster than hydrogen or the surrounding air, increasing the stability of the airship. When flying in slightly superadiabatic dry air, a hydrogen-filled airship is unstable in altitude. If it descends, the lifting gas heats up slower than the surrounding air, decreasing lift and accelerating the descent. This is no problem for helium-filled airships. Those have difficulty changing altitude faster than the time needed to equalise inside and outside temperature.</dd> <dd>When looking at fatalities per passenger-kilometre, it's best to look only at passenger flights. Including military flights, test flights and accidents on the ground will increase the number of accidents without adding passenger-kilometres, making the airship appear more dangerous. Worse, those were the most dangerous occasions for airships. Ground accidents happened when the airship was grounded for bad weather, test flights were obviously more dangerous than regular flights and even when excluding combat damage, military flights were more dangerous as the airship was flown in weather and through manoeuvres that no captain would attempt on a civilian flight. However, excluding all military flights will exclude all helium-filled rigid airships, so no useful statistics are left. The safety record of those four helium-filled rigid airships of the US Navy doesn't appear too good though: three fatal crashes in only a third of the flight hours of Graf Zeppelin. <a href="/wiki/User:PiusImpavidus" title="User:PiusImpavidus">PiusImpavidus</a> (<a href="/wiki/User_talk:PiusImpavidus" title="User talk:PiusImpavidus">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-PiusImpavidus-20241117165000-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100" class="ext-discussiontools-init-timestamplink">16:50, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-PiusImpavidus-20241117165000-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-PiusImpavidus-20241117165000-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"></span></dd></dl> <dl><dd><span data-mw-comment-start="" id="c-Baseball_Bugs-20241117205500-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"></span>As noted in <a href="/wiki/List_of_airship_accidents" title="List of airship accidents">List of airship accidents</a>, there is a variety of causes, a number of them being weather-related. The most successful airship was the <a href="/wiki/LZ_127_Graf_Zeppelin" title="LZ 127 Graf Zeppelin">Graf Zeppelin</a>, which was filled with hydrogen, but never burned up or crashed. ←<a href="/wiki/User:Baseball_Bugs" title="User:Baseball Bugs">Baseball Bugs</a> <sup><i><a href="/wiki/User_talk:Baseball_Bugs" title="User talk:Baseball Bugs">What's up, Doc?</a></i></sup> <a href="/wiki/Special:Contributions/Baseball_Bugs" title="Special:Contributions/Baseball Bugs">carrots</a>→ <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Baseball_Bugs-20241117205500-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100" class="ext-discussiontools-init-timestamplink">20:55, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Baseball_Bugs-20241117205500-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Baseball_Bugs-20241117205500-2601:646:8082:BA0:CD5E:73B7:6DF6:2CF6-20241117034100"></span></dd></dl> <dl><dd><dl><dd><span data-mw-comment-start="" id="c-Alansplodge-20241119155600-Baseball_Bugs-20241117205500"></span>There were no helium-filled passenger airships - they were all operated for naval reconnaisance. <a href="/wiki/User:Alansplodge" title="User:Alansplodge">Alansplodge</a> (<a href="/wiki/User_talk:Alansplodge" title="User talk:Alansplodge">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Alansplodge-20241119155600-Baseball_Bugs-20241117205500" class="ext-discussiontools-init-timestamplink">15:56, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Alansplodge-20241119155600-Baseball_Bugs-20241117205500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Alansplodge-20241119155600-Baseball_Bugs-20241117205500"></span> <dl><dd><span data-mw-comment-start="" id="c-PiusImpavidus-20241121095700-Alansplodge-20241119155600"></span>There are some modern helium-filled non-rigid or semi-rigid passenger airships, used for sightseeing, but there are no hydrogen-filled modern airships, so there's no useful comparison possible. There are both helium-filled and hydrogen-filled gas balloons, but that isn't really the same thing. <a href="/wiki/User:PiusImpavidus" title="User:PiusImpavidus">PiusImpavidus</a> (<a href="/wiki/User_talk:PiusImpavidus" title="User talk:PiusImpavidus">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-PiusImpavidus-20241121095700-Alansplodge-20241119155600" class="ext-discussiontools-init-timestamplink">09:57, 21 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-PiusImpavidus-20241121095700-Alansplodge-20241119155600"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-PiusImpavidus-20241121095700-Alansplodge-20241119155600"></span></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Land_surveying" data-mw-thread-id="h-Land_surveying-November_17-20241117160100"><span data-mw-comment-start="" id="h-Land_surveying-November_17-20241117160100"></span>Land surveying<span data-mw-comment-end="h-Land_surveying-November_17-20241117160100"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=18" title="Edit section: Land surveying"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-40bus-20241117160100-Land_surveying"></span>Does modern land surveying (such as placement of streets after another, width of roads and blocks etc.) in take place using metric units in countries such as Canada, Australia and New Zealand, which have used metric distances for many decades now? Is there any English-speaking country that had already metricated when first surveys for 19th-century cities were done? Are there any downtown grids in English-speaking areas where streets are placed exactly 100 metres apart, and there are ten streets per one kilometre? In grids that place 16 streets per mile, the number of metres passed eventually deviates from number of 100 metres (hectometres) passed, since one mile is not exactly 1,600 metres. Placing ten streets per mile indicates number of miles passed by fourth-to last digit of house numbers, but does not indicate number of feet (or any other imperial unit) passed by whole number. By contrast, placing ten streets per kilometre indicates both number of kilometres passed by fourt-to last digit of house numbers and number of metres passed by whole house numbers. This placing is common in Argentina, but does it occur in any English-speaking country? --<a href="/wiki/User:40bus" title="User:40bus">40bus</a> (<a href="/wiki/User_talk:40bus" title="User talk:40bus">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-40bus-20241117160100-Land_surveying" class="ext-discussiontools-init-timestamplink">16:01, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-40bus-20241117160100-Land_surveying"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-40bus-20241117160100-Land_surveying"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Sagittarian_Milky_Way-20241118054800-40bus-20241117160100"></span>There are 100 meter blocks in Melbourne, Australia if I remember correctly. Mile/km/block-based addresses is not the original England way which was to count plots or buildings and call an unexpected new building in between the address of its neighbor suffixed with a letter or fraction. Manhattan's a hybrid: 1 address pair per 20ft plot of ownable (non-street) distance except 1 axis is 100 per block causing gaps like 153, 155, 201 except 3LPM5's 100 per 2 blocks cause Lex+Mad are new. <a href="/wiki/User:Sagittarian_Milky_Way" title="User:Sagittarian Milky Way">Sagittarian Milky Way</a> (<a href="/wiki/User_talk:Sagittarian_Milky_Way" title="User talk:Sagittarian Milky Way">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Sagittarian_Milky_Way-20241118054800-40bus-20241117160100" class="ext-discussiontools-init-timestamplink">05:48, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Sagittarian_Milky_Way-20241118054800-40bus-20241117160100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Sagittarian_Milky_Way-20241118054800-40bus-20241117160100"></span> <dl><dd><span data-mw-comment-start="" id="c-Alansplodge-20241119153800-Sagittarian_Milky_Way-20241118054800"></span>The Melbourne blocks are 200 metres and then only by a coincidence; they are actually 10 <a href="/wiki/Chain_(unit)" title="Chain (unit)">chains</a> or 660 feet, which happily converts to 201.17 metres. See <a href="/wiki/Hoddle_Grid" title="Hoddle Grid">Hoddle Grid</a> for the details. <a href="/wiki/User:Alansplodge" title="User:Alansplodge">Alansplodge</a> (<a href="/wiki/User_talk:Alansplodge" title="User talk:Alansplodge">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Alansplodge-20241119153800-Sagittarian_Milky_Way-20241118054800" class="ext-discussiontools-init-timestamplink">15:38, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Alansplodge-20241119153800-Sagittarian_Milky_Way-20241118054800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Alansplodge-20241119153800-Sagittarian_Milky_Way-20241118054800"></span> <dl><dd><span data-mw-comment-start="" id="c-TrogWoolley-20241118094100-Alansplodge-20241119153800"></span>This is a new South Australian development near to where I live and the blocks are measured in metres, but not in nice whole metres. Zoom in and move the map to see details of the blocks. <a rel="nofollow" class="external free" href="https://villawoodproperties.com.au/community/oakden-rise/find-buy/interactive-masterplan/">https://villawoodproperties.com.au/community/oakden-rise/find-buy/interactive-masterplan/</a> <a href="/wiki/User:TrogWoolley" title="User:TrogWoolley">TrogWoolley</a> (<a href="/wiki/User_talk:TrogWoolley" title="User talk:TrogWoolley">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-TrogWoolley-20241118094100-Alansplodge-20241119153800" class="ext-discussiontools-init-timestamplink">09:41, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-TrogWoolley-20241118094100-Alansplodge-20241119153800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-TrogWoolley-20241118094100-Alansplodge-20241119153800"></span></dd> <dd><span data-mw-comment-start="" id="c-Sagittarian_Milky_Way-20241120012900-Alansplodge-20241119153800"></span>The same inaccuracy as 16 per mile then. <a href="/wiki/User:Sagittarian_Milky_Way" title="User:Sagittarian Milky Way">Sagittarian Milky Way</a> (<a href="/wiki/User_talk:Sagittarian_Milky_Way" title="User talk:Sagittarian Milky Way">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Sagittarian_Milky_Way-20241120012900-Alansplodge-20241119153800" class="ext-discussiontools-init-timestamplink">01:29, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Sagittarian_Milky_Way-20241120012900-Alansplodge-20241119153800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Sagittarian_Milky_Way-20241120012900-Alansplodge-20241119153800"></span></dd></dl></dd></dl></dd></dl> <dl><dd><span data-mw-comment-start="" id="c-Alansplodge-20241119155400-40bus-20241117160100"></span>Just to note that Australia, South Africa, New Zealand and Canada all began <a href="/wiki/Metrication" title="Metrication">metrication</a> in the 1960s or very early 1970s, so using metric measurements for any official purposes in the 19th-century would be highly improbable. <a href="/wiki/User:Alansplodge" title="User:Alansplodge">Alansplodge</a> (<a href="/wiki/User_talk:Alansplodge" title="User talk:Alansplodge">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Alansplodge-20241119155400-40bus-20241117160100" class="ext-discussiontools-init-timestamplink">15:54, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Alansplodge-20241119155400-40bus-20241117160100"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Alansplodge-20241119155400-40bus-20241117160100"></span> <dl><dd><span data-mw-comment-start="" id="c-40bus-20241119212000-Alansplodge-20241119155400"></span>Is the any English-speaking country that already used metric measurement for official purposes in the 19th century? Was there anything that was measured in metric during <a href="/wiki/Victorian_times" class="mw-redirect" title="Victorian times">Victorian times</a> in the UK? --<a href="/wiki/User:40bus" title="User:40bus">40bus</a> (<a href="/wiki/User_talk:40bus" title="User talk:40bus">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-40bus-20241119212000-Alansplodge-20241119155400" class="ext-discussiontools-init-timestamplink">21:20, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-40bus-20241119212000-Alansplodge-20241119155400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-40bus-20241119212000-Alansplodge-20241119155400"></span> <dl><dd><span data-mw-comment-start="" id="c-Card_Zero-20241120062600-40bus-20241119212000"></span>There was apparently a 6 mm government cartridge specification, the <a href="/wiki/6mm_Lee_Navy" title="6mm Lee Navy">6mm Lee Navy</a>. I haven't dug up a contemporary source using mm, but it looks like it was so named even in 1895. (Note though the alternate .236 name.) <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241120062600-40bus-20241119212000" class="ext-discussiontools-init-timestamplink">06:26, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241120062600-40bus-20241119212000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241120062600-40bus-20241119212000"></span> <dl><dd><dl><dd><a rel="nofollow" class="external text" href="https://books.google.co.uk/books?id=oR9BAQAAMAAJ&pg=PA480"><i><span data-mw-comment-start="" id="c-Alansplodge-20241120124400-Card_Zero-20241120062600"></span>The Abridgment: Containing Messages of the President of the United States to the Two Houses of Congress</i> (1898) p. 480</a>:</dd> <dd><span class="example" style="font-family: Georgia, 'DejaVu Serif', serif; color: var(--color-content-added, #006400);">"Ten thousand 6 mm. Lee straight pull rifles have been supplied..."</span> <a href="/wiki/User:Alansplodge" title="User:Alansplodge">Alansplodge</a> (<a href="/wiki/User_talk:Alansplodge" title="User talk:Alansplodge">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Alansplodge-20241120124400-Card_Zero-20241120062600" class="ext-discussiontools-init-timestamplink">12:44, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Alansplodge-20241120124400-Card_Zero-20241120062600"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Alansplodge-20241120124400-Card_Zero-20241120062600"></span></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-Alansplodge-20241120123300-Card_Zero-20241120062600"></span>On the subject of weapons, the <a href="/wiki/QF_2-pounder_naval_gun" title="QF 2-pounder naval gun">QF 2-pounder naval gun</a> of 1915 was made by the very British firm of <a href="/wiki/Vickers" title="Vickers">Vickers</a> and had a calibre of exactly 40 mm, but was known in British service by the weight of its shell in Imperial measure. The use of metric units here may be connected with the acquisition by Vickers of the <a href="/wiki/Maxim_Nordenfelt_Guns_and_Ammunition_Company" title="Maxim Nordenfelt Guns and Ammunition Company">Maxim Nordenfelt Guns and Ammunition Company</a> in 1897, which although a British company, had its origin in the company owned by <a href="/wiki/Thorsten_Nordenfelt" title="Thorsten Nordenfelt">Thorsten Nordenfelt</a>, a Swedish inventor. <a href="/wiki/User:Alansplodge" title="User:Alansplodge">Alansplodge</a> (<a href="/wiki/User_talk:Alansplodge" title="User talk:Alansplodge">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Alansplodge-20241120123300-Card_Zero-20241120062600" class="ext-discussiontools-init-timestamplink">12:33, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Alansplodge-20241120123300-Card_Zero-20241120062600"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Alansplodge-20241120123300-Card_Zero-20241120062600"></span></dd></dl></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-PiusImpavidus-20241119193100-Alansplodge-20241119155400"></span>A near miss though. Québec was a French colony using French units until 1763, switched to Imperial units after that, which was only 32 years before France metricated.</dd> <dd>South Africa is an even nearer miss. It (or at least, the Cape Colony) was a Dutch colony until 1795, which is the year when the Netherlands metricated. The British then introduced Imperial units as they took over. Dutch rule was briefly restored in 1803–1806, but it appears this was too short to make the switch to metric. The Boers went their own way, continuing the use of traditional Dutch units (no longer used in the Netherlands) until Imperial units were made the standard in 1922: one of the last countries to switch to Imperial units. <a href="/wiki/User:PiusImpavidus" title="User:PiusImpavidus">PiusImpavidus</a> (<a href="/wiki/User_talk:PiusImpavidus" title="User talk:PiusImpavidus">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-PiusImpavidus-20241119193100-Alansplodge-20241119155400" class="ext-discussiontools-init-timestamplink">19:31, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-PiusImpavidus-20241119193100-Alansplodge-20241119155400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-PiusImpavidus-20241119193100-Alansplodge-20241119155400"></span></dd></dl></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="How_sampling_rate_in_ADC_adjusted_or_set_?" data-mw-thread-id="h-How_sampling_rate_in_ADC_adjusted_or_set_?-November_17-20241117183600"><span id="How_sampling_rate_in_ADC_adjusted_or_set_.3F"></span><span data-mw-comment-start="" id="h-How_sampling_rate_in_ADC_adjusted_or_set_?-November_17-20241117183600"></span>How sampling rate in ADC adjusted or set ?<span data-mw-comment-end="h-How_sampling_rate_in_ADC_adjusted_or_set_?-November_17-20241117183600"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=19" title="Edit section: How sampling rate in ADC adjusted or set ?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-HarryOrange-20241117183600-How_sampling_rate_in_ADC_adjusted_or_set_?"></span>I am interested to learn how sampling rate in <a href="/wiki/Analog-to-digital_converter" title="Analog-to-digital converter">Analog-to-digital converter</a> adjusted or set ? This page: <a href="/wiki/Sampling_(signal_processing)" title="Sampling (signal processing)">Sampling (signal processing)</a> didn't explain how it was adjusted. <a href="/w/index.php?title=User:HarryOrange&action=edit&redlink=1" class="new" title="User:HarryOrange (page does not exist)">HarryOrange</a> (<a href="/w/index.php?title=User_talk:HarryOrange&action=edit&redlink=1" class="new" title="User talk:HarryOrange (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-HarryOrange-20241117183600-How_sampling_rate_in_ADC_adjusted_or_set_?" class="ext-discussiontools-init-timestamplink">18:36, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-HarryOrange-20241117183600-How_sampling_rate_in_ADC_adjusted_or_set_?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-HarryOrange-20241117183600-How_sampling_rate_in_ADC_adjusted_or_set_?"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Greglocock-20241117220000-HarryOrange-20241117183600"></span>Do you mean on a black box ADC (the sort of thing you have in a lab), or do you mean on an adc chip? <a href="/wiki/User:Greglocock" title="User:Greglocock">Greglocock</a> (<a href="/wiki/User_talk:Greglocock" title="User talk:Greglocock">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Greglocock-20241117220000-HarryOrange-20241117183600" class="ext-discussiontools-init-timestamplink">22:00, 17 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Greglocock-20241117220000-HarryOrange-20241117183600"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Greglocock-20241117220000-HarryOrange-20241117183600"></span> <dl><dd><span data-mw-comment-start="" id="c-HarryOrange-20241118050300-Greglocock-20241117220000"></span>@<a href="/wiki/User:Greglocock" title="User:Greglocock">Greglocock</a> I mean any typical ADC chip. How Sampling rate is adjusted? <a href="/w/index.php?title=User:HarryOrange&action=edit&redlink=1" class="new" title="User:HarryOrange (page does not exist)">HarryOrange</a> (<a href="/w/index.php?title=User_talk:HarryOrange&action=edit&redlink=1" class="new" title="User talk:HarryOrange (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-HarryOrange-20241118050300-Greglocock-20241117220000" class="ext-discussiontools-init-timestamplink">05:03, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-HarryOrange-20241118050300-Greglocock-20241117220000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-HarryOrange-20241118050300-Greglocock-20241117220000"></span></dd> <dd><span data-mw-comment-start="" id="c-Greglocock-20241118060400-Greglocock-20241117220000"></span>I guess you read the data sheet for the chip. eg p41 and 42 here <a rel="nofollow" class="external free" href="https://www.analog.com/media/en/technical-documentation/data-sheets/ad7768-7768-4.pdf">https://www.analog.com/media/en/technical-documentation/data-sheets/ad7768-7768-4.pdf</a> <a href="/wiki/User:Greglocock" title="User:Greglocock">Greglocock</a> (<a href="/wiki/User_talk:Greglocock" title="User talk:Greglocock">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Greglocock-20241118060400-Greglocock-20241117220000" class="ext-discussiontools-init-timestamplink">06:04, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Greglocock-20241118060400-Greglocock-20241117220000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Greglocock-20241118060400-Greglocock-20241117220000"></span> <dl><dd><span data-mw-comment-start="" id="c-Philvoids-20241119201700-Greglocock-20241118060400"></span>An ADC sampling rate is determined by the data rate of the desired digital audio format. <a href="/wiki/Sampling_(signal_processing)" title="Sampling (signal processing)">This article</a> gives many examples of which 44.1 kHz, 48 kHz, 88.2 kHz and 96 kHz are typical. A designer simply ensures that an ADC chip receives a digital clock signal at appropriate frequency. <a href="/w/index.php?title=User:Philvoids&action=edit&redlink=1" class="new" title="User:Philvoids (page does not exist)">Philvoids</a> (<a href="/wiki/User_talk:Philvoids" title="User talk:Philvoids">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Philvoids-20241119201700-Greglocock-20241118060400" class="ext-discussiontools-init-timestamplink">20:17, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Philvoids-20241119201700-Greglocock-20241118060400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Philvoids-20241119201700-Greglocock-20241118060400"></span> <dl><dd><span data-mw-comment-start="" id="c-Greglocock-20241119215500-Philvoids-20241119201700"></span>Which is almost irrelevant to the question. An ADC chip or lab instrument can sample at many different rates. <a href="/wiki/User:Greglocock" title="User:Greglocock">Greglocock</a> (<a href="/wiki/User_talk:Greglocock" title="User talk:Greglocock">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Greglocock-20241119215500-Philvoids-20241119201700" class="ext-discussiontools-init-timestamplink">21:55, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Greglocock-20241119215500-Philvoids-20241119201700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Greglocock-20241119215500-Philvoids-20241119201700"></span></dd></dl></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_18" data-mw-thread-id="h-November_18-20241118000900"><span data-mw-comment-start="" id="h-November_18-20241118000900"></span>November 18<span data-mw-comment-end="h-November_18-20241118000900"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=20" title="Edit section: November 18"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Open-air_dust_explosions" data-mw-thread-id="h-Open-air_dust_explosions-November_18-20241118000900"><span data-mw-comment-start="" id="h-Open-air_dust_explosions-November_18-20241118000900"></span>Open-air dust explosions<span data-mw-comment-end="h-Open-air_dust_explosions-November_18-20241118000900"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=21" title="Edit section: Open-air dust explosions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><a href="/wiki/Dust_explosion#Conditions_required" title="Dust explosion"><span data-mw-comment-start="" id="c-Card_Zero-20241118000900-Open-air_dust_explosions"></span>Dust explosion#Conditions required</a> says <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1248585704"><q class="inline-quote-talk">There are five necessary conditions for a dust explosion</q>. It even has a pointless diagram that arranges the five conditions in a pentagon with "dust explosion" in the middle. Condition 5 is confinement. But further down the page, <a href="/wiki/Dust_explosion#Mechanism" title="Dust explosion">Dust_explosion#Mechanism</a> has a series of photographs demonstrating a dust explosion in open air. And <a href="/wiki/Thermobaric_weapons" class="mw-redirect" title="Thermobaric weapons">thermobaric weapons</a>, although more effective at killing people in confined spaces, seem to explode just fine in the open. So is condition 5, as a "necessary condition", plain wrong, perhaps an exaggeration of the fact that confinement makes a dust explosion more likely? </p><p>Supplementary question: I hear residents of Lahore and Delhi are wondering if their very sooty smog might one day explode. Is this at all plausible? <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241118000900-Open-air_dust_explosions" class="ext-discussiontools-init-timestamplink">00:09, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241118000900-Open-air_dust_explosions"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241118000900-Open-air_dust_explosions"></span> </p> <dl><dd><dl><dd><span style="font-size:85%;"><span data-mw-comment-start="" id="c-Lambiam-20241118065300-Card_Zero-20241118000900"></span>Pointless? It is a five-pointed diagram. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241118065300-Card_Zero-20241118000900" class="ext-discussiontools-init-timestamplink">06:53, 18 November 2024 (UTC)</a><span data-mw-comment-end="c-Lambiam-20241118065300-Card_Zero-20241118000900"></span></span><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241118065300-Card_Zero-20241118000900"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span></dd></dl></dd> <dd><span data-mw-comment-start="" id="c-Lambiam-20241118090500-Card_Zero-20241118000900"></span>In general, not only for dust, for <a href="/wiki/Detonation" title="Detonation">detonation</a> to occur, a mix of fuel and oxygen within the <a href="/wiki/Explosive_limits" class="mw-redirect" title="Explosive limits">explosive limits</a> has to be present in a compact largish volume. Upon detonation, the pressure in this volume will rapidly increase tremendously within (typically) microseconds. If the volume is not confined by an enclosure, the gases resulting from the combustion will expand supersonically with a shock wave that may or may not cause damage, depending on the power released and the environment. If the volume is confined by an enclosure, the enclosure may be able to withstand the pressure and contain the gases – possibly with controlled release through <a href="/wiki/Safety_valve" title="Safety valve">safety valves</a>. (See e.g. <a href="/wiki/Pyr%C3%A9olophore" title="Pyréolophore">Pyréolophore</a>.) Otherwise, if the enclosure is broached, the gases will also expand explosively.</dd> <dd>The OSHA fact sheet that is the source of our five-pointed list of conditions is actually about another scenario. It considers the case in which ignition merely leads to <a href="/wiki/Deflagration" title="Deflagration">deflagration</a>, which is much more likely to occur – the mix only has to be within <a href="/wiki/Inflammability_limits" class="mw-redirect" title="Inflammability limits">inflammability limits</a>. The combustion is much slower and does by itself not cause a shock wave. However, although the pressure rises less rapidly, the rise is still dramatic, especially if the volume is contained by an enclosure. If the enclosure cannot withstand the pressure, the gases will also expand explosively, as before.</dd> <dd>So I think a fuel–oxygen explosion can occur in open air, but for this to be an explosion in the strict sense of causing shock waves, the right conditions will only very rarely be fulfilled accidentally. (In thermobaric weapons, they are fulfilled by design.) --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241118090500-Card_Zero-20241118000900" class="ext-discussiontools-init-timestamplink">09:05, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241118090500-Card_Zero-20241118000900"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241118090500-Card_Zero-20241118000900"></span> <dl><dd><span data-mw-comment-start="" id="c-176.3.66.65-20241122151000-Lambiam-20241118090500"></span>But in the conditions there is no requirement of an accidental event?! <a href="/wiki/Special:Contributions/176.3.66.65" title="Special:Contributions/176.3.66.65">176.3.66.65</a> (<a href="/w/index.php?title=User_talk:176.3.66.65&action=edit&redlink=1" class="new" title="User talk:176.3.66.65 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-176.3.66.65-20241122151000-Lambiam-20241118090500" class="ext-discussiontools-init-timestamplink">15:10, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-176.3.66.65-20241122151000-Lambiam-20241118090500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-176.3.66.65-20241122151000-Lambiam-20241118090500"></span> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241123120000-176.3.66.65-20241122151000"></span>The OSHA fact sheet does not deal with ways to mitigate the risk of intentional explosions, such as may be caused by weapons. You are free to see this as an omission; I doubt though they will agree. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241123120000-176.3.66.65-20241122151000" class="ext-discussiontools-init-timestamplink">12:00, 23 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241123120000-176.3.66.65-20241122151000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241123120000-176.3.66.65-20241122151000"></span></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Delayed_onset_muscle_soreness" data-mw-thread-id="h-Delayed_onset_muscle_soreness-November_18-20241118165300"><span data-mw-comment-start="" id="h-Delayed_onset_muscle_soreness-November_18-20241118165300"></span><a href="/wiki/Delayed_onset_muscle_soreness" title="Delayed onset muscle soreness">Delayed onset muscle soreness</a><span data-mw-comment-end="h-Delayed_onset_muscle_soreness-November_18-20241118165300"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=22" title="Edit section: Delayed onset muscle soreness"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-CometVolcano-20241118165300-Delayed_onset_muscle_soreness"></span>How long does it last and how to recover from it? <a href="/w/index.php?title=User:CometVolcano&action=edit&redlink=1" class="new" title="User:CometVolcano (page does not exist)">CometVolcano</a> (<a href="/wiki/User_talk:CometVolcano" title="User talk:CometVolcano">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-CometVolcano-20241118165300-Delayed_onset_muscle_soreness" class="ext-discussiontools-init-timestamplink">16:53, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-CometVolcano-20241118165300-Delayed_onset_muscle_soreness"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-CometVolcano-20241118165300-Delayed_onset_muscle_soreness"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Amble-20241118171100-CometVolcano-20241118165300"></span>According to the article: "It peaks from 24 to 72 hours, then subsides and disappears up to seven days after exercise." --<a href="/wiki/User:Amble" title="User:Amble">Amble</a> (<a href="/wiki/User_talk:Amble" title="User talk:Amble">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Amble-20241118171100-CometVolcano-20241118165300" class="ext-discussiontools-init-timestamplink">17:11, 18 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Amble-20241118171100-CometVolcano-20241118165300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Amble-20241118171100-CometVolcano-20241118165300"></span></dd> <dd><span data-mw-comment-start="" id="c-AndrewWTaylor-20241119141500-CometVolcano-20241118165300"></span>From the top of this page: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1248585704"><q class="inline-quote-talk">We don't answer (and may remove) questions that require medical diagnosis..</q>. <a href="/wiki/User:AndrewWTaylor" title="User:AndrewWTaylor">AndrewWTaylor</a> (<a href="/wiki/User_talk:AndrewWTaylor" title="User talk:AndrewWTaylor">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-AndrewWTaylor-20241119141500-CometVolcano-20241118165300" class="ext-discussiontools-init-timestamplink">14:15, 19 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-AndrewWTaylor-20241119141500-CometVolcano-20241118165300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-AndrewWTaylor-20241119141500-CometVolcano-20241118165300"></span> <dl><dd><span data-mw-comment-start="" id="c-Abductive-20241120102700-AndrewWTaylor-20241119141500"></span>It is said that the soreness is helped by consuming protein. <span style="font-family: Cambria;"> <a href="/wiki/User:Abductive" title="User:Abductive"><span style="color: teal;"><b>Abductive</b></span></a> (<a href="/wiki/User_talk:Abductive" title="User talk:Abductive">reasoning</a>)</span> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Abductive-20241120102700-AndrewWTaylor-20241119141500" class="ext-discussiontools-init-timestamplink">10:27, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Abductive-20241120102700-AndrewWTaylor-20241119141500"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Abductive-20241120102700-AndrewWTaylor-20241119141500"></span></dd></dl></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_20" data-mw-thread-id="h-November_20-20241120194300"><span data-mw-comment-start="" id="h-November_20-20241120194300"></span>November 20<span data-mw-comment-end="h-November_20-20241120194300"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=23" title="Edit section: November 20"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="John_Balbus_and_Steven_Balbus" data-mw-thread-id="h-John_Balbus_and_Steven_Balbus-November_20-20241120194300"><span data-mw-comment-start="" id="h-John_Balbus_and_Steven_Balbus-November_20-20241120194300"></span>John Balbus and Steven Balbus<span data-mw-comment-end="h-John_Balbus_and_Steven_Balbus-November_20-20241120194300"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=24" title="Edit section: John Balbus and Steven Balbus"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-178.51.16.158-20241120194300-John_Balbus_and_Steven_Balbus"></span>Are <a href="/wiki/Steven_Balbus" title="Steven Balbus">Steven Balbus</a> (Oxford University astrophysicist) and John Balbus (Head of Office of Climate Change and Health Equity in Biden's <a href="/wiki/United_States_Department_of_Health_and_Human_Services" title="United States Department of Health and Human Services">HHS</a>) related? <a href="/wiki/Special:Contributions/178.51.16.158" title="Special:Contributions/178.51.16.158">178.51.16.158</a> (<a href="/wiki/User_talk:178.51.16.158" title="User talk:178.51.16.158">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-178.51.16.158-20241120194300-John_Balbus_and_Steven_Balbus" class="ext-discussiontools-init-timestamplink">19:43, 20 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-178.51.16.158-20241120194300-John_Balbus_and_Steven_Balbus"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-178.51.16.158-20241120194300-John_Balbus_and_Steven_Balbus"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-94.1.211.243-20241121021300-178.51.16.158-20241120194300"></span>Given their mutual association with Philadelphia and their strong physical resemblance, it seems very likely, but I haven't been able to find any source confirming it with a cursory web search, so this might take some deep digging (better suited to someone in the USA, not Europe). John Balbus, incidentally, seems to me to be a good candidate for a Wikipedia article. {The poster formerly known as 87.812.230.195} <a href="/wiki/Special:Contributions/94.1.211.243" title="Special:Contributions/94.1.211.243">94.1.211.243</a> (<a href="/wiki/User_talk:94.1.211.243" title="User talk:94.1.211.243">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-94.1.211.243-20241121021300-178.51.16.158-20241120194300" class="ext-discussiontools-init-timestamplink">02:13, 21 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-94.1.211.243-20241121021300-178.51.16.158-20241120194300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-94.1.211.243-20241121021300-178.51.16.158-20241120194300"></span></dd> <dd><span data-mw-comment-start="" id="c-Lambiam-20241121100900-178.51.16.158-20241120194300"></span>They are brothers, with a third brother named Peter.<sup><a rel="nofollow" class="external autonumber" href="https://www.penncharter.com/about-us/news-media/news-details-page/~board/alumni/post/pc-profile-john-balbus-opc78">[1]</a></sup> <a rel="nofollow" class="external text" href="https://issuu.com/penncharter/docs/pc_2023fallmagazine_final"><u>Here</u></a> on p. 33 is a photo of Steven en John side by side. Their father was Theodore G. Balbus,<sup><a rel="nofollow" class="external autonumber" href="https://www.legacy.com/us/obituaries/inquirer/name/theodore-balbus-obituary?id=10391295">[2]</a></sup> a radiologist, and their mother Rita S. Frucht.<sup><a rel="nofollow" class="external autonumber" href="https://www.nytimes.com/1952/01/28/archives/rita-s-frucht-married-bride-of-dr-theodore-g-balbus-at-ceremony-in.html">[3]</a></sup> A bio of the father is found <a rel="nofollow" class="external text" href="https://lm0610.wordpress.com/"><u>here</u></a>, where you can also find that Peter runs a consulting firm called Pragmaxis. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241121100900-178.51.16.158-20241120194300" class="ext-discussiontools-init-timestamplink">10:09, 21 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241121100900-178.51.16.158-20241120194300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241121100900-178.51.16.158-20241120194300"></span></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_21" data-mw-thread-id="h-November_21-20241121193700"><span data-mw-comment-start="" id="h-November_21-20241121193700"></span>November 21<span data-mw-comment-end="h-November_21-20241121193700"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=25" title="Edit section: November 21"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Griffiths_in_math_and_physics" data-mw-thread-id="h-Griffiths_in_math_and_physics-November_21-20241121193700"><span data-mw-comment-start="" id="h-Griffiths_in_math_and_physics-November_21-20241121193700"></span>Griffiths in math and physics<span data-mw-comment-end="h-Griffiths_in_math_and_physics-November_21-20241121193700"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=26" title="Edit section: Griffiths in math and physics"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-Gongula_Spring-20241121193700-Griffiths_in_math_and_physics"></span>There's something called the <a href="https://arxiv.org/abs/1009.0395" class="extiw" title="arxiv:1009.0395">Griffiths phase</a>. If you search for griffiths phase activity <a rel="nofollow" class="external text" href="https://arxiv.org/search/?query=griffiths+phase+activity&searchtype=all&source=header">so</a>, you'll find things with similar names. A Griffiths singularity, Griffiths effects, there's probably more than one thing people call Griffiths' formula since there's a physicist called <a href="/wiki/Phillip_Griffiths" title="Phillip Griffiths">Phillip</a> and two named <a href="/wiki/David_J._Griffiths" title="David J. Griffiths">David J. Griffiths</a>. How many things are we dealing with under this name? Is there a book where they're all listed right next to each other? <a href="/w/index.php?title=User:Gongula_Spring&action=edit&redlink=1" class="new" title="User:Gongula Spring (page does not exist)">Gongula Spring</a> (<a href="/wiki/User_talk:Gongula_Spring" title="User talk:Gongula Spring">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Gongula_Spring-20241121193700-Griffiths_in_math_and_physics" class="ext-discussiontools-init-timestamplink">19:37, 21 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Gongula_Spring-20241121193700-Griffiths_in_math_and_physics"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Gongula_Spring-20241121193700-Griffiths_in_math_and_physics"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241121234300-Gongula_Spring-20241121193700"></span>The concept of a Griffiths phase is named after theoretical physicist <a href="/wiki/Robert_B._Griffiths" class="mw-redirect" title="Robert B. Griffiths">Robert B. Griffiths</a>, who was the first to describe the appearance of such phases in an <a href="/wiki/Ising_model" title="Ising model">Ising model</a> of <a href="/wiki/Ferromagnetism" title="Ferromagnetism">ferromagnetism</a>.<sup><a rel="nofollow" class="external autonumber" href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.23.17">[4]</a></sup> He is also the eponym of the <a href="/wiki/Griffiths_inequality" title="Griffiths inequality">Griffiths inequality</a>. Most uses of <i>Griffiths singularity</i> and <i>Griffiths effect</i> appear to be related. "Griffiths' formula" is a very general name that may refer to various formulas found by mathematicians with the surname Griffiths, such as Griffiths' integral formula for the <a href="/wiki/Milnor_number" title="Milnor number">Milnor number</a> of an isolated hypersurface singularity, found by pure mathematician <a href="/wiki/Philip_A._Griffiths" class="mw-redirect" title="Philip A. Griffiths">Philip A. Griffiths</a>, also the eponym of the <a href="/wiki/Griffiths_group" title="Griffiths group">Griffiths group</a>. See also <a href="/wiki/Griffiths%27_theorem" title="Griffiths' theorem">Griffiths' theorem</a>, named after yet another Griffiths. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241121234300-Gongula_Spring-20241121193700" class="ext-discussiontools-init-timestamplink">23:43, 21 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241121234300-Gongula_Spring-20241121193700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241121234300-Gongula_Spring-20241121193700"></span> <dl><dd><a rel="nofollow" class="external text" href="https://link.springer.com/article/10.1007/s10704-024-00786-3"><span data-mw-comment-start="" id="c-Askedonty-20241122001300-Lambiam-20241121234300"></span>That formulation</a> seems at least superficially be leading to references to <a href="/wiki/Alan_Arnold_Griffith" title="Alan Arnold Griffith">Alan Arnold Griffith</a>. Formulas like <i>ohmic or non ohmic dissipation in metallic griffiths phases</i> used at <a rel="nofollow" class="external text" href="https://allthingsfsu.blogspot.com/2017/08/fsu-lab-sets-new-magnet-strength-record.html">the National High Magnetic Field Laboratory</a> then tend to appear ambiguous to that effect too. Most other examples are deeply plunging into statistical quanta states thus unambiguously associated with Robert B. Griffiths instead. --<a href="/wiki/User:Askedonty" title="User:Askedonty">Askedonty</a> (<a href="/wiki/User_talk:Askedonty" title="User talk:Askedonty">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Askedonty-20241122001300-Lambiam-20241121234300" class="ext-discussiontools-init-timestamplink">00:13, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Askedonty-20241122001300-Lambiam-20241121234300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Askedonty-20241122001300-Lambiam-20241121234300"></span> <dl><dd><span data-mw-comment-start="" id="c-Lambiam-20241122084700-Askedonty-20241122001300"></span>The bracketing is not as in ((Griffith phase) field theory) but like (Griffith ((phase field) theory)), a theory of fracture, based on a phase-field model, developed by Griffith. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241122084700-Askedonty-20241122001300" class="ext-discussiontools-init-timestamplink">08:47, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241122084700-Askedonty-20241122001300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241122084700-Askedonty-20241122001300"></span> <dl><dd><span data-mw-comment-start="" id="c-Askedonty-20241122105100-Lambiam-20241122084700"></span>The interesting thing is that those approaches are leading us very near of a (a least to me ) finally rather satisfying view of the problematics induced by the idea of <a href="/wiki/Action_at_a_distance" title="Action at a distance">Action at a distance</a>. --<a href="/wiki/User:Askedonty" title="User:Askedonty">Askedonty</a> (<a href="/wiki/User_talk:Askedonty" title="User talk:Askedonty">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Askedonty-20241122105100-Lambiam-20241122084700" class="ext-discussiontools-init-timestamplink">10:51, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Askedonty-20241122105100-Lambiam-20241122084700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Askedonty-20241122105100-Lambiam-20241122084700"></span></dd> <dd><span data-mw-comment-start="" id="c-Askedonty-20241122110000-Lambiam-20241122084700"></span>So much that you only have to think about it and what do you get? <a rel="nofollow" class="external text" href="https://arxiv.org/pdf/1111.5364#:~:text=Robert%20Griffiths%20begins%20his%20recent%20paper%20Quantum%20Locality,long%20distances%2C%20in%20apparent%20contradiction%20to%20special%20relativity%E2%80%9D.">Long distances in apparent contradiction to..</a> --<a href="/wiki/User:Askedonty" title="User:Askedonty">Askedonty</a> (<a href="/wiki/User_talk:Askedonty" title="User talk:Askedonty">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Askedonty-20241122110000-Lambiam-20241122084700" class="ext-discussiontools-init-timestamplink">11:00, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Askedonty-20241122110000-Lambiam-20241122084700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Askedonty-20241122110000-Lambiam-20241122084700"></span> <dl><dd><span data-mw-comment-start="" id="c-Gongula_Spring-20241122155400-Askedonty-20241122110000"></span>I'm not sure if these long distances anticipate my next question, which is what does "long-range" mean in the <a rel="nofollow" class="external text" href="https://arxiv.org/search/?query=griffiths+phase+activity&searchtype=all&source=header">search</a> results above?</dd> <dd><a href="/w/index.php?title=User:Gongula_Spring&action=edit&redlink=1" class="new" title="User:Gongula Spring (page does not exist)">Gongula Spring</a> (<a href="/wiki/User_talk:Gongula_Spring" title="User talk:Gongula Spring">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Gongula_Spring-20241122155400-Askedonty-20241122110000" class="ext-discussiontools-init-timestamplink">15:54, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Gongula_Spring-20241122155400-Askedonty-20241122110000"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Gongula_Spring-20241122155400-Askedonty-20241122110000"></span> <dl><dd><span data-mw-comment-start="" id="c-Askedonty-20241122163900-Gongula_Spring-20241122155400"></span>Perhaps, as in #16 from that request as I get it "Temporal disorder in discontinuous non-equilibrium phase transitions: general results". The "long distances" discussion above being from 2002 by contrast. --<a href="/wiki/User:Askedonty" title="User:Askedonty">Askedonty</a> (<a href="/wiki/User_talk:Askedonty" title="User talk:Askedonty">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Askedonty-20241122163900-Gongula_Spring-20241122155400" class="ext-discussiontools-init-timestamplink">16:39, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Askedonty-20241122163900-Gongula_Spring-20241122155400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Askedonty-20241122163900-Gongula_Spring-20241122155400"></span> <dl><dd><span data-mw-comment-start="" id="c-Gongula_Spring-20241122170500-Askedonty-20241122163900"></span>Number 16 uses "temporal" and "critical" terms, are we getting toward <a rel="nofollow" class="external text" href="http://criticaloscillations.org/publications.html">ideas</a> <a href="//doi.org/10.1101/2022.12.14.519751" class="extiw" title="doi:10.1101/2022.12.14.519751">about</a> long-range temporal correlations in critical brain dynamics? Are they spooky?</dd> <dd><a href="/w/index.php?title=User:Gongula_Spring&action=edit&redlink=1" class="new" title="User:Gongula Spring (page does not exist)">Gongula Spring</a> (<a href="/wiki/User_talk:Gongula_Spring" title="User talk:Gongula Spring">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Gongula_Spring-20241122170500-Askedonty-20241122163900" class="ext-discussiontools-init-timestamplink">17:05, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Gongula_Spring-20241122170500-Askedonty-20241122163900"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Gongula_Spring-20241122170500-Askedonty-20241122163900"></span></dd></dl></dd></dl></dd></dl></dd></dl></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_22" data-mw-thread-id="h-November_22-20241122012700"><span data-mw-comment-start="" id="h-November_22-20241122012700"></span>November 22<span data-mw-comment-end="h-November_22-20241122012700"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=27" title="Edit section: November 22"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Heat_of_chillies" data-mw-thread-id="h-Heat_of_chillies-November_22-20241122012700"><span data-mw-comment-start="" id="h-Heat_of_chillies-November_22-20241122012700"></span>Heat of chillies<span data-mw-comment-end="h-Heat_of_chillies-November_22-20241122012700"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=28" title="Edit section: Heat of chillies"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-146.90.140.99-20241122012700-Heat_of_chillies"></span>How hot, in terms of Scovilles, does a chilli need to be before a parrot can feel the burn? I just saw a video on Facebook of a macaw eating a ghost pepper without the slightest care. From what I read, parrots are extremely resistant to the capsicum from chillies. Or is it because we have thousands of taste buds and parrots have tens, which is also true. <a href="/wiki/Special:Contributions/146.90.140.99" title="Special:Contributions/146.90.140.99">146.90.140.99</a> (<a href="/w/index.php?title=User_talk:146.90.140.99&action=edit&redlink=1" class="new" title="User talk:146.90.140.99 (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-146.90.140.99-20241122012700-Heat_of_chillies" class="ext-discussiontools-init-timestamplink">01:27, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-146.90.140.99-20241122012700-Heat_of_chillies"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-146.90.140.99-20241122012700-Heat_of_chillies"></span> </p> <dl><dd><span data-mw-comment-start="" id="c-Card_Zero-20241122032200-146.90.140.99-20241122012700"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1248585704"><q class="inline-quote-talk">“The seeds of Capsicum plants are dispersed predominantly by birds. In birds, the TRPV1 channel does not respond to <a href="/wiki/Capsaicin" title="Capsaicin">capsaicin</a> or related chemicals but mammalian TRPV1 is very sensitive to it. This is advantageous to the plant, as chili pepper seeds consumed by birds pass through the digestive tract and can germinate later, whereas mammals have molar teeth which destroy such seeds and prevent them from germinating.”</q> <a href="/wiki/User:Card_Zero" title="User:Card Zero"><span style="background-color:#fffff0; border:1px #995; border-style:dotted solid solid dotted;"> Card Zero </span></a> <a href="/wiki/User_talk:Card_Zero" title="User talk:Card Zero">(talk)</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Card_Zero-20241122032200-146.90.140.99-20241122012700" class="ext-discussiontools-init-timestamplink">03:22, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Card_Zero-20241122032200-146.90.140.99-20241122012700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Card_Zero-20241122032200-146.90.140.99-20241122012700"></span></dd> <dd><span data-mw-comment-start="" id="c-Sean.hoyland-20241122033200-146.90.140.99-20241122012700"></span>Yes, as Card Zero says, birds have different <a href="/wiki/TRPV" title="TRPV">TRPV</a> receptors (for <a href="/wiki/Vanilloids" class="mw-redirect" title="Vanilloids">vanilloids</a> like capsaicin) than mammals. I guess chillis want their seeds distributed far and wide by birds. On the other hand, I've never seen anything eat the chillis that accidentally grow in my garden. Interestingly, my dog appears to have different TRPV receptors than me as they don't seem to notice very spicy chilli seeds on food and they won't be damaging the seeds. <a href="/wiki/User:Sean.hoyland" title="User:Sean.hoyland">Sean.hoyland</a> (<a href="/wiki/User_talk:Sean.hoyland" title="User talk:Sean.hoyland">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Sean.hoyland-20241122033200-146.90.140.99-20241122012700" class="ext-discussiontools-init-timestamplink">03:32, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Sean.hoyland-20241122033200-146.90.140.99-20241122012700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Sean.hoyland-20241122033200-146.90.140.99-20241122012700"></span></dd> <dd><span data-mw-comment-start="" id="c-Shantavira-20241122092300-146.90.140.99-20241122012700"></span>Indeed, one of the most effective ways to keep squirrels off my bird feeder is to sprinkle the birdseed with chilli powder. <a href="/wiki/User:Shantavira" title="User:Shantavira">Shantavira</a>|<a href="/wiki/User_talk:Shantavira" title="User talk:Shantavira"><sup>feed me</sup></a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Shantavira-20241122092300-146.90.140.99-20241122012700" class="ext-discussiontools-init-timestamplink">09:23, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Shantavira-20241122092300-146.90.140.99-20241122012700"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Shantavira-20241122092300-146.90.140.99-20241122012700"></span> <dl><dd><span data-mw-comment-start="" id="c-HiLo48-20241122100800-Shantavira-20241122092300"></span>My entire home crop of capsicums (bell peppers to Americans), and some chillis disappeared in one night last summer right after a colony of fruit bats arrived in my local park. Fruit bats, of course, are mammals. <a href="/wiki/User:HiLo48" title="User:HiLo48">HiLo48</a> (<a href="/wiki/User_talk:HiLo48" title="User talk:HiLo48">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-HiLo48-20241122100800-Shantavira-20241122092300" class="ext-discussiontools-init-timestamplink">10:08, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-HiLo48-20241122100800-Shantavira-20241122092300"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-HiLo48-20241122100800-Shantavira-20241122092300"></span> <dl><dd><span data-mw-comment-start="" id="c-Sean.hoyland-20241122155000-HiLo48-20241122100800"></span>That's interesting because there are many bats here. They often sleep individually or in small groups inside young banana leaves that haven't unfurled yet. They sometimes crash into me at night if I'm moving. I guess in bat-world tree-like things don't move. They seem to have a chilli-free diet but might eat some of the other fruit. Plenty of insects to eat. Bat teeth <a rel="nofollow" class="external text" href="https://www.nature.com/articles/s41467-023-40158-4">seem to be quite diverse</a> molar-wise. Chilli is the only thing that survives the wildlife. It's a multi-belligerent fruit-based forever war over resources with the birds, squirrels, rats, countless insects, fungi, bacteria and viruses. <a href="/wiki/User:Sean.hoyland" title="User:Sean.hoyland">Sean.hoyland</a> (<a href="/wiki/User_talk:Sean.hoyland" title="User talk:Sean.hoyland">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Sean.hoyland-20241122155000-HiLo48-20241122100800" class="ext-discussiontools-init-timestamplink">15:50, 22 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Sean.hoyland-20241122155000-HiLo48-20241122100800"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Sean.hoyland-20241122155000-HiLo48-20241122100800"></span></dd></dl></dd></dl></dd></dl> <div class="mw-heading mw-heading1"><h1 id="November_23" data-mw-thread-id="h-November_23-20241123072400"><span data-mw-comment-start="" id="h-November_23-20241123072400"></span>November 23<span data-mw-comment-end="h-November_23-20241123072400"></span></h1><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=29" title="Edit section: November 23"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading2 ext-discussiontools-init-section"><h2 id="Before_Puberty,_sex_organs_are_not_functional?" data-mw-thread-id="h-Before_Puberty,_sex_organs_are_not_functional?-November_23-20241123072400"><span id="Before_Puberty.2C_sex_organs_are_not_functional.3F"></span><span data-mw-comment-start="" id="h-Before_Puberty,_sex_organs_are_not_functional?-November_23-20241123072400"></span>Before <a href="/wiki/Puberty" title="Puberty">Puberty</a>, sex organs are not functional?<span data-mw-comment-end="h-Before_Puberty,_sex_organs_are_not_functional?-November_23-20241123072400"></span></h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&section=30" title="Edit section: Before Puberty, sex organs are not functional?"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span><div class="ext-discussiontools-init-section-bar"><div class="ext-discussiontools-init-section-metadata"></div><div class="ext-discussiontools-init-section-actions"></div></div></div> <p><span data-mw-comment-start="" id="c-HarryOrange-20241123072400-Before_Puberty,_sex_organs_are_not_functional?"></span>How do sex organs function in both genders before puberty in humans? Not after <a href="/wiki/Puberty" title="Puberty">Puberty</a>. <a href="/w/index.php?title=User:HarryOrange&action=edit&redlink=1" class="new" title="User:HarryOrange (page does not exist)">HarryOrange</a> (<a href="/w/index.php?title=User_talk:HarryOrange&action=edit&redlink=1" class="new" title="User talk:HarryOrange (page does not exist)">talk</a>) <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-HarryOrange-20241123072400-Before_Puberty,_sex_organs_are_not_functional?" class="ext-discussiontools-init-timestamplink">07:24, 23 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-HarryOrange-20241123072400-Before_Puberty,_sex_organs_are_not_functional?"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-HarryOrange-20241123072400-Before_Puberty,_sex_organs_are_not_functional?"></span> </p> <dl><dd><a href="/wiki/Sexual_maturity" title="Sexual maturity"><span data-mw-comment-start="" id="c-Lambiam-20241123115100-HarryOrange-20241123072400"></span>Sexual maturity</a> is only reached during <a href="/wiki/Puberty" title="Puberty">puberty</a>. Before it is reached, the sex organs are not (or not yet fully) functional. See also <a href="/wiki/Sex_organ#Development" title="Sex organ">Sex organ § Development</a> and <a href="/wiki/Precocious_puberty" title="Precocious puberty">Precocious puberty</a>. --<a href="/wiki/User_talk:Lambiam#top" title="User talk:Lambiam">Lambiam</a> <a href="https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#c-Lambiam-20241123115100-HarryOrange-20241123072400" class="ext-discussiontools-init-timestamplink">11:51, 23 November 2024 (UTC)</a><span class="ext-discussiontools-init-replylink-buttons" data-mw-thread-id="c-Lambiam-20241123115100-HarryOrange-20241123072400"><span class="ext-discussiontools-init-replylink-bracket">[</span><a class="ext-discussiontools-init-replylink-reply" role="button" tabindex="0" href="">reply</a><span class="ext-discussiontools-init-replylink-bracket">]</span></span><span data-mw-comment-end="c-Lambiam-20241123115100-HarryOrange-20241123072400"></span></dd></dl>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&oldid=1259108625">https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&oldid=1259108625</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Wikipedia_resources_for_researchers" title="Category:Wikipedia resources for researchers">Wikipedia resources for researchers</a></li><li><a href="/wiki/Category:Wikipedia_help_forums" title="Category:Wikipedia help forums">Wikipedia help forums</a></li><li><a href="/wiki/Category:Wikipedia_reference_desk" title="Category:Wikipedia reference desk">Wikipedia reference desk</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Non-talk_pages_that_are_automatically_signed" title="Category:Non-talk pages that are automatically signed">Non-talk pages that are automatically signed</a></li><li><a href="/wiki/Category:Pages_automatically_checked_for_incorrect_links" title="Category:Pages automatically checked for incorrect links">Pages automatically checked for incorrect links</a></li><li><a href="/wiki/Category:Wikipedia_help_pages_with_dated_sections" title="Category:Wikipedia help pages with dated sections">Wikipedia help pages with dated sections</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 23 November 2024, at 12:00<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. 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