The Most Misunderstood Concept in Physics

Published 2023-07-01
One of the most important, yet least understood, concepts in all of physics. Head to to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.

If you're looking for a molecular modeling kit, try Snatoms - a kit I invented where the atoms snap together magnetically:

A huge thank you to those who helped us understand different aspects of this complicated topic - Dr. Ashmeet Singh, Supriya Krishnamurthy, Dr. Jos Thijssen, Dr. Bijoy Bera, Dr. Timon Idema, Álvaro Bermejillo Seco and Dr. Misha Titov.

Carnot, S. (1824). Reflections on the motive power of heat: and on machines fitted to develop that power. -

Harnessing The True Power Of Atoms | Order And Disorder Documentaries, Spark via YouTube -

A better description of entropy, Steve Mould via YouTube -

Dugdale, J. S. (1996). Entropy and its physical meaning. CRC Press. -

Schroeder, D. V. (1999). An introduction to thermal physics. -

Fowler, M. Heat Engines: the Carnot Cycle, University of Virginia. -

Chandler, D.L. (2010). Explained: The Carnot Limit, MIT News -

Entropy, Wikipedia -

Clausius, R. (1867). The mechanical theory of heat. Van Voorst. -

What is entropy? TED-Ed via YouTube -

Thijssen, J. (2018) Lecture Notes Statistical Physics, TU Delft.

Schneider, E. D., & Kay, J. J. (1994). Life as a manifestation of the second law of thermodynamics. Mathematical and computer modelling, 19(6-8), 25-48. -

Lineweaver, C. H., & Egan, C. A. (2008). Life, gravity and the second law of thermodynamics. Physics of Life Reviews, 5(4), 225-242. -

Michaelian, K. (2012). HESS Opinions" Biological catalysis of the hydrological cycle: life's thermodynamic function". Hydrology and Earth System Sciences, 16(8), 2629-2645. -

England, J. L. (2013). Statistical physics of self-replication. The Journal of chemical physics, 139(12), 09B623_1. -

England, J. L. (2015). Dissipative adaptation in driven self-assembly. Nature nanotechnology, 10(11), 919-923. -

Wolchover, N. (2014). A New Physics Theory of Life, Quantamagazine -

Lineweaver, C. H. (2013). The entropy of the universe and the maximum entropy production principle. In Beyond the Second Law: Entropy Production and Non-equilibrium Systems (pp. 415-427). Berlin, Heidelberg: Springer Berlin Heidelberg. -

Bekenstein, J.D. (1972). Black holes and the second law. Lett. Nuovo Cimento 4, 737–740. -

Carroll, S.M. (2022). The Biggest Ideas in the Universe: Space, Time, and Motion. Penguin Publishing Group. -

Black hole thermodynamics, Wikipedia -

Cosmology and the arrow of time: Sean Carroll at TEDxCaltech, TEDx Talks via YouTube -

Carroll, S. M. (2008). The cosmic origins of time’s arrow. Scientific American, 298(6), 48-57. -

The Passage of Time and the Meaning of Life | Sean Carroll (Talk + Q&A), Long Now Foundation via YouTube -

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Written by Casper Mebius, Derek Muller & Petr Lebedev
Edited by Trenton Oliver & Jamie MacLeod
Animated by Mike Radjabov, Ivy Tello, Fabio Albertelli and Jakub Misiek
Filmed by Derek Muller, Albert Leung & Raquel Nuno
Molecular collisions video by CSIRO's Data61 via YouTube: Simulation of air
Additional video/photos supplied by Getty Images, Pond5 and by courtesy of NASA, NASA's Goddard Space Flight Center, NASA Goddard Flight Lab/ CI Lab, NASA/SDO and the AIA, EVE, HMI, and WMAP science teams. As well as the Advanced Visualization Laboratory at the National Center for Supercomputing Applications, B. Robertson, L. Hernquist
Music from Epidemic Sound & Jonny Hyman
Produced by Derek Muller, Petr Lebedev, Emily Zhang, & Casper Mebius

All Comments (21)
  • @ketchup2707
    For those of you that haven’t taken a thermodynamics course yet, I don’t think you realize how incredibly helpful this video is lol
  • @0biwan7
    the three laws of thermodynamics: 1. you can't win 2. you can't break even 3. you can't stop playing the game
  • @serenarose54
    15:47 to 16:27 . That has to be one of the best cinematography I've ever seen. The narration, the visuals and the background music especially. Best build up to reveal the Star of the talk (quite literally)
  • @TimeBucks
    This has to be one of the best Veritasium episodes.
  • @SteveMould
    The thing about one photon from the sun turning into several spreading out in all directions answered a long standing question for me - how to explain the way the sun “powers” life on earth in terms of entropy. Thanks!
  • @kaptainkobb1920
    I am not being hyperbolic here... I am 10 minutes into this video and it is already more useful than my entire undergraduate thermodynamics class. Thank you for making this all make sense 5 years later.
  • The feeling of realizing the idea before its actually clarified, only to be validated a few moments later is irreplaceable. It amazes me that this kind of information doesn't give everyone the goosebumps.
  • @twofishes8846
    About 5 years ago discoved this show. At 69 years old your show now sends me daily down that wonderful rabbit hole... the world wide web gushing with information. I feel like I finally rediscovered the wonder and excitement of a being alive! And ready and armed to discover the unknown with childlike wonder... Thank you all for making life an incredible adventure... again!
  • @SupratimBhowmick
    I was a student of physics. Today at the age of 57 I understood what entropy actually means. Thank you.
  • The way that this video builds out concepts and then extrapolates them into more complex contexts is so excellent.
  • As an HVAC professional for over a decade, I truly appreciate the inclusion of heat transfer in real world applications. Thanks for the shout out! I also want to thank you for using a Trane TWR heat pump for the explanation portion, and not for the "this is why HVAC is bad" shot 😅 Im gonna go tell a customer that their cold air is actually making it hotter sometimes 😂❤
  • @jacobcannon1493
    The effort to put this presentation together and for millions to view has used energy very effectively. Please spread out more heat like this over time.
  • @tomaskujinek
    It is incredible how you can explain complex topic in 20 minutes that everyone grab a basic concept of it. Love it. Keep it going.
  • @N0Xa880iUL
    This video is eye opening, life changing, pp touching, etc.
  • @chinoleemil8392
    The parallel you drew there with the arrow of time was quite surprising and truly fascinating! Great videos, as always!
  • @emilydelano555
    This has to be one of the best Veritasium episodes. I got goose bumps because of the beauty of the explanation. Science is so awe inspiring.
  • @nakulsprakash1640
    I'm a chemical engineer, and I always hated the way they defined Entropy to us in textbooks or how teachers would explain it to us. They say Entropy is disorder or randomness which never really tells you what it is. I never completely understood the concept but watching this now after all those years it looks like yes it was so obvious, it is disorder now I get it why it is defined asdisorder.
  • @wpkzz
    I have a phD also in Physics and I loved this video. It didn't say anything that I did not know: but it stated it in a very palatable and enjoyable way, good voice, perfect explanations, easy to grasp. An excellent lesson should I say.
  • @JeeAspirantAIR1
    This is quite possibly THE most BEAUTIFUL video I've ever seen. I always felt like I hadn't understood entropy, and this video explained it in such a way that I could understand and visualize. Thank you so much.