[{"@context":"https:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/blog.terabox.com\/insights\/principle-of-least-action-physics-guide#BlogPosting","mainEntityOfPage":"https:\/\/blog.terabox.com\/insights\/principle-of-least-action-physics-guide","headline":"The Principle of Least Action: The Law That Governs Physics","name":"The Principle of Least Action: The Law That Governs Physics","description":"\ud83d\udcfa Today’s recommended deep-dive video: https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs The Secret Rule that Governs the Entire UniverseThe Battle of the BrachistochroneFrom Light to ActionThe Birth of the LagrangianWhy Use Action Over Force?Key TakeawaysQ&A The Secret Rule that Governs the Entire Universe From the... ","datePublished":"2026-08-18","dateModified":"2026-08-18","author":{"@type":"Person","@id":"https:\/\/blog.terabox.com\/author\/flextech-admin\/#Person","name":"flextech-admin","url":"https:\/\/blog.terabox.com\/author\/flextech-admin\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/ad516503a11cd5ca435acc9bb6523536?s=150&d=mm&r=gforcedefault=1","url":"https:\/\/secure.gravatar.com\/avatar\/ad516503a11cd5ca435acc9bb6523536?s=150&d=mm&r=gforcedefault=1","height":96,"width":96}},"publisher":{"@type":"Organization","name":"terabox","logo":{"@type":"ImageObject","@id":"http:\/\/blog.terabox.com\/wp-content\/uploads\/2021\/11\/logo\u4ea7\u54c1\u540d-\u7ad6\u7248.png","url":"http:\/\/blog.terabox.com\/wp-content\/uploads\/2021\/11\/logo\u4ea7\u54c1\u540d-\u7ad6\u7248.png","width":900,"height":900}},"image":{"@type":"ImageObject","@id":"https:\/\/img.youtube.com\/vi\/Q10_srZ-pbs\/maxresdefault.jpg","url":"https:\/\/img.youtube.com\/vi\/Q10_srZ-pbs\/maxresdefault.jpg","height":"","width":""},"url":"https:\/\/blog.terabox.com\/insights\/principle-of-least-action-physics-guide","video":{"@context":"http:\/\/schema.org\/","@type":"VideoObject","@id":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs#VideoObject","contentUrl":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs","name":"The Closest We\u2019ve Come to a Theory of Everything","description":"The single principle that underpins all of physics. Head to https:\/\/brilliant.org\/veritasium to start your free 30-day trial and get 20% off an annual premium subscription.\n\nA massive thank you to Prof. Steven Strogatz for his expertise and enthusiasm. As an exclusive bonus for our Patreon members, we've posted a longer interview with Prof. Strogatz over there: https:\/\/www.patreon.com\/posts\/principle-of-116042877\n\nA huge thank you to Prof. Haithem Taha, Prof. Anthony Bloch, Dr. Carl-Fredrik Nyberg Brodda, Dr. Sarah Millholland, and Dr. Andrew Mitchell for all their help with finding the story and getting it right.\n\nA special thanks to Dr. Aur\u00e8le Adam, Ron Haaksman, Marc Serra Peralta, and everyone at the Delft Makerspace for their help with preparing and performing experiments.\n\n00:00 One rule that replaces all of physics\n00:51 The problem of fastest descent\n05:09 Fermat's principle\n07:17 Bernoulli's solution\n10:38 Maupertuis' principle\n12:28 Maupertuis attacked and ridiculed\n14:01 Euler & Lagrange to the rescue\n17:22 The general approach to solving these problems\n19:32 Writing the principle into its modern form\n23:17 Why the principle works\n27:08 Another way to do mechanics\n30:19 A \u201cspooky\u201d breakthrough\n\n\u2580\u2580\u2580\nJoin us on Patreon for early access videos and exclusive bonus content https:\/\/ve42.co\/PatreonDE   \n\nPatrons: Adam Foreman, Anton Ragin, Balkrishna Heroor, Bertrand Serlet, Bill Linder, Blake Byers, Burt Humburg, Chris Harper, Dave Kircher, David Johnston, Evgeny Skvortsov, Garrett Mueller, Gnare, gpoly, I. H., John H. Austin, Jr., john kiehl, Josh Hibschman, Juan Benet, KeyWestr, Kyi, Lee Redden, Marinus Kuivenhoven, Martin, Matthias Wrobel, Max Paladino, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, Richard Sundvall, Sam Lutfi, Stephen Wilcox, Tj Steyn, Toni , TTST, Ubiquity Ventures, wolfee\n\nIf you\u2019re looking for a molecular modeling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https:\/\/ve42.co\/SnatomsV  \n\n\u2580\u2580\u2580\nKey references:\n\nA fantastic book on the history of the Principle of Least Action: Rojo, A. and Bloch, A. The \nPrinciple of Least Action: History and Physics. - https:\/\/ve42.co\/Bloch2018 \nCoopersmith, J.  (2017). The lazy universe: an introduction to the principle of least action. Oxford University Press. - https:\/\/ve42.co\/LazyU \n3Blue1Brown. The Brachistochrone, with Steven Strogatz via Youtube - https:\/\/ve42.co\/Brach3B1B \nVsauce. The Brachistochrone via Youtube - https:\/\/ve42.co\/BrachV \nPBS Space Time. Is ACTION The Most Fundamental Property in Physics? via Youtube - https:\/\/ve42.co\/PBSAction \n\nFull list of references: https:\/\/ve42.co\/LeastActionRefs\n\nImages & Video:\nVoltaire. (1753). Diatribe du Docteur Akakia. - https:\/\/ve42.co\/DiatribeAkakia \nPhilosophical Transactions cover. via Wikimedia Commons - https:\/\/ve42.co\/PhilTransImage \nKids Fun Science. (Jun 28, 2017). Refraction of Light with a arrow experiment via Youtube - https:\/\/ve42.co\/RefractionFunSci \nPhysics with Simon Poliakoff. Refraction demonstration with water and laser via Youtube - https:\/\/ve42.co\/SimonPoliakoff \nMercury Transit Across Sun. via Nasa.gov - https:\/\/ve42.co\/MercTransit \n\n\n\u2580\u2580\u2580\nDirected by Casper Mebius\nWritten by Casper Mebius and Derek Muller\nEdited by Trenton Oliver\nAnimated by Fabio Albertelli, Ivy Tello, Mike Radjabov, Gregor \u010cavlovi\u0107, Emma Wright, James Finnemore and David Szakaly\nIllustrated by Jakub Misiek, Emma Wright, and Maria Gusakovich\nFilmed by Derek Muller and Casper Mebius\nAdditional research by Gabe Strong, Gregor \u010cavlovi\u0107, and Geeta Thakur\nProduced by Casper Mebius, Derek Muller, Rob Beasley Spence, Gabe Strong, Gregor \u010cavlovi\u0107, and Tori Brittain\nThumbnail contributions by Jakub Misiek, Ren Hurley and Peter Sheppard\nAdditional video\/photos supplied by Getty Images, Storyblocks, and NASA SVS\nMusic from Epidemic Sound","thumbnailUrl":["https:\/\/i.ytimg.com\/vi\/Q10_srZ-pbs\/default.jpg","https:\/\/i.ytimg.com\/vi\/Q10_srZ-pbs\/mqdefault.jpg","https:\/\/i.ytimg.com\/vi\/Q10_srZ-pbs\/hqdefault.jpg","https:\/\/i.ytimg.com\/vi\/Q10_srZ-pbs\/sddefault.jpg","https:\/\/i.ytimg.com\/vi\/Q10_srZ-pbs\/maxresdefault.jpg"],"uploadDate":"2024-10-29T12:09:04+00:00","duration":"PT32M44S","embedUrl":"https:\/\/www.youtube.com\/embed\/Q10_srZ-pbs","publisher":{"@type":"Organization","@id":"https:\/\/www.youtube.com\/channel\/UCHnyfMqiRRG1u-2MsSQLbXA#Organization","url":"https:\/\/www.youtube.com\/channel\/UCHnyfMqiRRG1u-2MsSQLbXA","name":"Veritasium","description":"An element of truth - videos about science, education, and anything else we find interesting.","logo":{"url":"https:\/\/yt3.ggpht.com\/7vCbvtCqtjQ3YLgsJt7Y952MQV1sBvhllSCSxHP8_sVZdcPCBrITfhkN2RdyCuwPnsByq-1GoA=s800-c-k-c0x00ffffff-no-rj","width":800,"height":800,"@type":"ImageObject","@id":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs#VideoObject_publisher_logo_ImageObject"}},"potentialAction":{"@type":"SeekToAction","@id":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs#VideoObject_potentialAction","target":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs&t={seek_to_second_number}","startOffset-input":"required name=seek_to_second_number"},"interactionStatistic":[[{"@type":"InteractionCounter","@id":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs#VideoObject_interactionStatistic_WatchAction","interactionType":{"@type":"WatchAction"},"userInteractionCount":17382606}],{"@type":"InteractionCounter","@id":"https:\/\/www.youtube.com\/watch?v=Q10_srZ-pbs#VideoObject_interactionStatistic_LikeAction","interactionType":{"@type":"LikeAction"},"userInteractionCount":379042}]},"about":["Insights","\u300eEnglish\u300f"],"wordCount":1349},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Insights","item":"https:\/\/blog.terabox.com\/insights\/#breadcrumbitem"},{"@type":"ListItem","position":2,"name":"The Principle of Least Action: The Law That Governs Physics","item":"https:\/\/blog.terabox.com\/insights\/principle-of-least-action-physics-guide#breadcrumbitem"}]}]