{"id":120958,"date":"2024-11-01T20:57:45","date_gmt":"2024-11-01T13:57:45","guid":{"rendered":"https:\/\/hotvideos24.online\/?p=120958"},"modified":"2024-11-01T20:57:45","modified_gmt":"2024-11-01T13:57:45","slug":"scientists-caught-sperm-defying-one-of-the-laws-of-physics-sciencealert","status":"publish","type":"post","link":"https:\/\/hotvideos24.online\/?p=120958","title":{"rendered":"Scientists Caught Sperm Defying One of The Laws of Physics : ScienceAlert"},"content":{"rendered":"<p> <script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<\/p>\n<div>\n<p>With their whip-like tails, human sperm propel themselves through viscous fluids, seemingly in defiance of Newton&#8217;s third law of motion, according to a recent study that characterizes the motion of these sex cells and single-celled algae.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>Kenta Ishimoto, a mathematical scientist at Kyoto University, and colleagues investigated these non-reciprocal interactions in sperm and other microscopic biological swimmers, to figure out how they slither through substances that should, in theory, resist their movement.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>When Newton conceived his now-famed <a href=\"https:\/\/www1.grc.nasa.gov\/beginners-guide-to-aeronautics\/newtons-laws-of-motion\/\">laws of motion<\/a> in 1686, he sought to explain the relationship between a physical object and the forces acting upon it with a few neat principles that, it turns out, don&#8217;t necessarily apply to microscopic cells wriggling through sticky fluids.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>Newton&#8217;s third law can be summed up as &#8220;for every action, there is an equal and opposite reaction&#8221;. It signifies a particular symmetry in nature where opposing forces act against each other. In the simplest example, two equal-sized marbles colliding as they roll along the ground will transfer their force and rebound based on this law.<\/p>\n<figure id=\"attachment_142414\" aria-describedby=\"caption-attachment-142414\" style=\"width: 642px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" src=\"https:\/\/www.sciencealert.com\/images\/2024\/11\/ScanningElectronMicrographOfASpermCellR_U_642.jpg\" alt=\"Scanning electron micrograph of a sperm cell\" width=\"642\" height=\"642\" class=\"size-full wp-image-142414\" srcset=\"https:\/\/www.sciencealert.com\/images\/2024\/11\/ScanningElectronMicrographOfASpermCellR_U_642.jpg 642w, https:\/\/www.sciencealert.com\/images\/2024\/11\/ScanningElectronMicrographOfASpermCellR_U_642-415x415.jpg 415w, https:\/\/www.sciencealert.com\/images\/2024\/11\/ScanningElectronMicrographOfASpermCellR_U_642-600x600.jpg 600w\" sizes=\"auto, (max-width: 642px) 100vw, 642px\" loading=\"lazy\"\/><figcaption id=\"caption-attachment-142414\" class=\"wp-caption-text\">Scanning electron micrograph of a sperm cell in a fallopian tube. (<a href=\"https:\/\/www.canva.com\/photos\/MADmTORiqcE\/\">Science Photo Library\/Canva<\/a>)<\/figcaption><\/figure>\n<p>However, nature is chaotic, and <a href=\"https:\/\/doi.org\/10.1146\/annurev-conmatphys-040821-125506\">not all physical systems<\/a> are bound by these symmetries. So-called non-reciprocal interactions show up in unruly systems made up of flocking birds, <a href=\"https:\/\/www.nature.com\/articles\/s41598-020-70441-z\">particles in fluid<\/a> \u2013 and swimming sperm.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>These motile agents move in ways that display asymmetric interactions with the animals behind them or the fluids that surround them, forming a loophole for equal and opposite forces to skirt Newton&#8217;s third law.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>Because birds and cells <a href=\"https:\/\/www.quantamagazine.org\/a-new-theory-for-systems-that-defy-newtons-third-law-20211111\/\">generate their own energy<\/a>, which gets added to the system with each flap of their wings or whip of their tails, the system is thrust far from equilibrium, and the same rules don&#8217;t apply.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>In their study published in October 2023, Ishimoto and colleagues analyzed experimental data on human sperm and also modeled the motion of <a href=\"https:\/\/en.wikipedia.org\/wiki\/Chlamydomonas\">green algae<\/a>, <em>Chlamydomonas<\/em>. Both swim using thin, bendy <a href=\"https:\/\/en.wikipedia.org\/wiki\/Flagellum\">flagella<\/a> that protrude from the cell body and <a href=\"https:\/\/www.sciencealert.com\/mathematicians-find-strange-link-between-zebra-stripes-and-sperm-tails\">change shape<\/a>, or deform, to drive the cells forward.<\/p>\n<figure id=\"attachment_142410\" aria-describedby=\"caption-attachment-142410\" style=\"width: 642px\" class=\"wp-caption alignnone\"><img decoding=\"async\" src=\"https:\/\/www.sciencealert.com\/images\/2024\/09\/Untitled-design-1.jpg\" alt=\"A small green circle with bumps and two tiny string-like threads at the bottom\" width=\"642\" height=\"642\" class=\"size-full wp-image-142410\" srcset=\"https:\/\/www.sciencealert.com\/images\/2024\/09\/Untitled-design-1.jpg 642w, https:\/\/www.sciencealert.com\/images\/2024\/09\/Untitled-design-1-415x415.jpg 415w, https:\/\/www.sciencealert.com\/images\/2024\/09\/Untitled-design-1-600x600.jpg 600w\" sizes=\"auto, (max-width: 642px) 100vw, 642px\" loading=\"lazy\"\/><figcaption id=\"caption-attachment-142410\" class=\"wp-caption-text\">Green algae<em> (Chlamydomonas globosa) <\/em>with two flagella just visible at bottom left. (<a href=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/4\/4e\/Chlamydomonas_globosa_-_400x_%2813263097835%29.jpg\">Picturepest\/CC BY 2.0\/Wikimedia Commons<\/a>)<\/figcaption><\/figure>\n<p><a href=\"https:\/\/en.wikipedia.org\/wiki\/Scallop_theorem\">Highly viscous fluids<\/a> would typically dissipate a flagellum&#8217;s energy, preventing a sperm or single-celled algae from moving much at all. And yet somehow, the elastic flagella can propel these cells along without provoking a response from their surroundings.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>The researchers found that sperm tails and algal flagella have an &#8216;<a href=\"https:\/\/www.nature.com\/articles\/s41567-020-0795-y\">odd elasticity&#8217;<\/a>, which allows these flexible appendages to whip about without losing much energy to the surrounding fluid.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>But this property of odd elasticity didn&#8217;t fully explain the propulsion from the flagella&#8217;s wave-like motion. So from their modeling studies, the researchers also derived a new term, an odd elastic modulus, to describe the internal mechanics of flagella.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>&#8220;From solvable simple models to biological flagellar waveforms for <em>Chlamydomonas<\/em> and sperm cells, we studied the odd-bending modulus to decipher the nonlocal, nonreciprocal inner interactions within the material,&#8221; the researchers <a href=\"https:\/\/journals.aps.org\/prxlife\/abstract\/10.1103\/PRXLife.1.023002\">concluded<\/a>.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>The findings could help in the design of small, <a href=\"https:\/\/www.nature.com\/articles\/s41565-022-01268-0\">self-assembling robots<\/a> that mimic living materials, while the modeling methods could be used to better understand the underlying principles of collective behavior, the team <a href=\"https:\/\/journals.aps.org\/prxlife\/abstract\/10.1103\/PRXLife.1.023002\">said<\/a>.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>The study was published in<em> <a href=\"https:\/\/journals.aps.org\/prxlife\/abstract\/10.1103\/PRXLife.1.023002\">PRX Life<\/a>.<\/em><\/p>\n<p><em>An earlier version of this article was published in October 2023.<\/em><\/p>\n<\/p><\/div>\n<p><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<br \/><div data-type=\"_mgwidget\" data-widget-id=\"1660802\">\r\n<\/div>\r\n<script>(function(w,q){w[q]=w[q]||[];w[q].push([\"_mgc.load\"])})(window,\"_mgq\");\r\n<\/script>\r\n<br \/>\n<br \/><a href=\"https:\/\/www.sciencealert.com\/scientists-caught-sperm-defying-one-of-the-laws-of-physics\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>With their whip-like tails, human sperm propel themselves through viscous fluids, seemingly in defiance of Newton&#8217;s third law of motion, according to a recent study that characterizes the motion of &hellip; <a href=\"https:\/\/hotvideos24.online\/?p=120958\" class=\"more-link\">Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8628],"tags":[],"class_list":["post-120958","post","type-post","status-publish","format-standard","hentry","category-science","entry"],"_links":{"self":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/120958","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=120958"}],"version-history":[{"count":0,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/120958\/revisions"}],"wp:attachment":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=120958"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=120958"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=120958"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}