{"id":217638,"date":"2025-01-17T14:34:09","date_gmt":"2025-01-17T14:34:09","guid":{"rendered":"https:\/\/news.talkwithrattan.com\/index.php\/2025\/01\/17\/hula-hooping-robots-reveal-the-physics-behind-keeping-rings-aloft\/"},"modified":"2025-01-17T14:34:09","modified_gmt":"2025-01-17T14:34:09","slug":"hula-hooping-robots-reveal-the-physics-behind-keeping-rings-aloft","status":"publish","type":"post","link":"https:\/\/news.talkwithrattan.com\/index.php\/2025\/01\/17\/hula-hooping-robots-reveal-the-physics-behind-keeping-rings-aloft\/","title":{"rendered":"Hula-hooping robots reveal the physics behind keeping rings aloft"},"content":{"rendered":"<div style=\"text-align:center\"><img decoding=\"async\" src=\"https:\/\/i2.wp.com\/www.sciencenews.org\/e_conover?ssl=1\" class=\"attachment-post-thumbnail size-post-thumbnail wp-post-image\" alt=\"Hula-hooping robots reveal the physics behind keeping rings aloft\" title=\"Hula-hooping robots reveal the physics behind keeping rings aloft\" \/><\/div> \r\n<br><div>\n\t\t\t<div class=\"rich-text rich-text--with-sidebar single__rich-text___RmCDp\" data-component=\"video-embed\">\n\t\t\t\t\n\n\n\n\n<p>To keep a Hula-Hoop aloft, it helps to be in shape \u2014 literally.<\/p>\n\n\n\n<p>Experiments with gyrating, hoop-slinging robots have revealed how these spinning rings stay up despite the pull of gravity. The\u00a0<a href=\"https:\/\/www.pnas.org\/doi\/suppl\/10.1073\/pnas.2411588121\" target=\"_blank\" rel=\"noopener\">shape of the robot\u2019s body is a crucial factor<\/a>, researchers report in the Jan. 7\u00a0<em>Proceedings of the National Academy of Sciences<\/em>.<\/p>\n\n\n\n<p>The shape needs to have \u201chips\u201d \u2014 a slope that provides upward force to counteract gravity. And a \u201cwaist\u201d \u2014 curvature like an hourglass \u2014 keeps the hoop from drifting up or down and sliding off.<\/p>\n\n\n<aside class=\"sn-conversion rich-text rich-text--with-sidebar\">\n<style><![CDATA[\n.email-conversion {\n  border: 1px solid #ffcccb;\n  color: white;\n  margin-top: 50px;\n  background-image: url(\"\/wp-content\/themes\/sciencenews\/client\/src\/images\/cta-module@2x.jpg\");\n  padding: 20px;\n  clear: both;\n}\n\n]]><\/style>\n\n\n\n                        <style class=\"is-layout-flow 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!important;\n}]]><\/style>\n                        \n                        \n<\/aside>\n\n\n<p>Inspired by performers near his home in Greenwich Village, applied mathematician Leif Ristroph of New York University began considering the physics of Hula-Hoops. Previous studies, he and colleagues realized, hadn\u2019t explained how the hoop stays aloft. (Ristroph has a track record of tackling\u00a0quirky physics questions. His group recently investigated what would happen if a <a href=\"https:\/\/www.sciencenews.org\/article\/lawn-sprinklers-suck-water-physics\">lawn sprinkler sucked water in instead of shooting it out<\/a>.)<\/p>\n\n\n\n<p>So Ristroph and colleagues gave it a whirl. In experiments, a gyrating cylindrical robot couldn\u2019t keep a hoop from sliding down. It was missing the essential upward force, generated when a hoop swings over a sloped shape. But a cone-shaped robot, with a slope but no waistlike curve, also failed. If the hoop began toward the top of the cone, the upward force overpowered gravity, and the hoop would migrate up. If the hoop began toward the bottom, the upward force wasn\u2019t enough to keep it aloft, and it migrated down. But an hourglass-shaped robot kept a hoop steadily aloft.\u00a0<\/p>\n\n\n\n<p>People should be able to hula-hoop regardless of body shape, by adapting their gyrations based on position changes of the hoop. Indeed, the researchers were able to get a cone-shaped robot to hula-hoop by adjusting the rate of gyration depending on how high the hoop slid.<\/p>\n\n\n\n<p>A correct launch was also essential in the experiments. If the hoop started off too slow, the attempt would fail. In successful sessions, the hoop lined up with the gyrating body, such that the hoop and body always shifted in the same direction. That\u2019s also the best way to launch a hoop, Ristroph says.<\/p>\n\n\n\n<p>A final tip gleaned from the research: Bigger hoops are good for beginners \u2014 they can be supported with slower gyrations.<\/p>\n\n\n\n\t\t\t<\/div> <!-- \/.rich-text -->\n\t\t\t\n<footer class=\"article-footer__wrapper___eChRS article-footer__with-sidebar___9oDuK\">\n\t\t\t<p class=\"article-footer__feedback___sNXjz\">Questions or comments on this article? E-mail us at\u00a0<a href=\"https:\/\/www.sciencenews.org\/article\/mailto:feedback@sciencenews.org\">feedback@sciencenews.org<\/a> | <a href=\"https:\/\/www.sciencenews.org\/permission-republish\">Reprints FAQ<\/a><\/p>\n\t\n\t\n\t\n\t\n\n\n\t\n<div class=\"author-bio__wrapper___ODe-4\">\n\t\t\t<figure class=\"author-bio__figure___e3jd0\">\n\t\t\t<a class=\"author-bio__thumbnail___TixlC\" href=\"https:\/\/www.sciencenews.org\/author\/emily-conover\" aria-hidden=\"true\" tabindex=\"-1\">\n\t\t\t\t\t\t\t<\/a>\n\t\t<\/figure>\n\t\n\t<div class=\"author-bio__content___F9GU3\">\n\t\t\n\n\t\t<div class=\"author-bio__bio___jkxvt\">\n\t\t\t<p>Physics writer Emily Conover has a Ph.D. in physics from the University of Chicago. She is a two-time winner of the D.C. Science Writers\u2019 Association Newsbrief award.<\/p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n\n\t<aside class=\"sn-conversion rich-text rich-text--with-sidebar\">\n<style><![CDATA[\n.donate-box {\n  border-top: 7px solid red !important;\n  border: 1px solid #ffcccb;\n  margin-top: 50px;\n  background-color: #fdfbf2;\n  padding: 20px;\n}\n.from-nature-index__heading___AhgOe {\n  display: none;\n}\n]]><\/style>\n\n\n\n<style><![CDATA[.from-nature-index__heading___AhgOe {\n    display: none;\n}]]><\/style><div id=\"donateConversion\" class=\"wp-block-group donate-box\">\n<p class=\"has-text-align-left\" style=\"font-size:1.1em\">\nWe are at a critical time and <strong><mark>supporting science journalism \nis more important than ever<\/mark><\/strong>. <em>Science News<\/em> and our \nparent organization, the Society for Science, need your help to strengthen \nscientific literacy and ensure that important societal decisions are made \nwith science in mind.<\/p>\n\n<p class=\"has-text-align-left\" style=\"font-size:1.1em\">\nPlease \n<a href=\"https:\/\/www.sciencenews.org\/subscribe1-print-digital?key=9MENDCON&amp;utm_source=end-of-article&amp;utm_medium=site&amp;utm_campaign=non-sub-control\">\nsubscribe to <em>Science News<\/em> and <strong>add $16<\/strong><\/a> to expand \nscience literacy and understanding.\n<\/p>\n\n\n\n\n<\/div>\n<\/aside><\/footer>\n\t\t<\/div>\r\n<br>\r\n<br><a href=\"https:\/\/www.sciencenews.org\/article\/hula-hooping-robots-physics\">Source link <\/a>","protected":false},"excerpt":{"rendered":"<p>To keep a Hula-Hoop aloft, it helps to be in shape \u2014 literally. Experiments with gyrating, hoop-slinging robots have revealed how these spinning rings stay up despite the pull of gravity. The\u00a0shape of the robot\u2019s body is a crucial factor, researchers report in the Jan. 7\u00a0Proceedings of the National Academy of Sciences. 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