2024-10-29

[public] 2.19M views, 138K likes, dislikes audio only

Veritasium

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.

A massive thank you to Prof. Steven Strogatz for his expertise and enthusiasm.

A 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.

A special thanks to Dr. Aurèle Adam, Ron Haaksman, Marc Serra Peralta, and everyone at the Delft Makerspace for their help with preparing and performing experiments.

00:00 One rule that replaces all of physics

00:51 The problem of fastest descent

05:09 Fermat's principle

07:17 Bernoulli's solution

10:38 Maupertuis' principle

12:28 Maupertuis attacked and ridiculed

14:01 Euler & Lagrange to the rescue

17:22 The general approach to solving these problems

19:32 Writing the principle into its modern form

23:17 Why the principle works

27:08 Another way to do mechanics

30:19 A “spooky” breakthrough

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Join us on Patreon for early access videos and exclusive bonus content https://ve42.co/PatreonDE

Patrons: 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

If you’re looking for a molecular modeling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https://ve42.co/SnatomsV

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Key references:

A fantastic book on the history of the Principle of Least Action: Rojo, A. and Bloch, A. The

Principle of Least Action: History and Physics. - https://ve42.co/Bloch2018

Coopersmith, J. (2017). The lazy universe: an introduction to the principle of least action. Oxford University Press. - https://ve42.co/LazyU

3Blue1Brown. The Brachistochrone, with Steven Strogatz via Youtube - https://ve42.co/Brach3B1B

Vsauce. The Brachistochrone via Youtube - https://ve42.co/BrachV

PBS Space Time. Is ACTION The Most Fundamental Property in Physics? via Youtube - https://ve42.co/PBSAction

Full list of references: https://ve42.co/T

Images & Video:

Voltaire. (1753). Diatribe du Docteur Akakia. - https://ve42.co/DiatribeAkakia

Philosophical Transactions cover. via Wikimedia Commons - https://ve42.co/PhilTransImage

Kids Fun Science. (Jun 28, 2017). Refraction of Light with a arrow experiment via Youtube - https://ve42.co/RefractionFunSci

Physics with Simon Poliakoff. Refraction demonstration with water and laser via Youtube - https://ve42.co/SimonPoliakoff

Mercury Transit Across Sun. via Nasa.gov - https://ve42.co/MercTransit

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Directed by Casper Mebius

Written by Casper Mebius and Derek Muller

Edited by Trenton Oliver

Animated by Fabio Albertelli, Ivy Tello, Mike Radjabov, Gregor Čavlović, Emma Wright, James Finnemore and David Szakaly

Illustrated by Jakub Misiek, Emma Wright, and Maria Gusakovich

Filmed by Derek Muller and Casper Mebius

Additional research by Gabe Bean, Gregor Čavlović, and Geeta Thakur

Produced by Casper Mebius, Derek Muller, Rob Beasley Spence, Gabe Bean, Gregor Čavlović, and Tori Brittain

Thumbnail contributions by Jakub Misiek, Ren Hurley and Peter Sheppard

Additional video/photos supplied by Getty Images, Storyblocks, and NASA SVS

Music from Epidemic Sound