For decades, the Sleeping Beauty Problem has divided people between two answers. Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 of you will get 20% off an annual premium subscription.

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Many thanks to Dr. Mike Titelbaum and Dr. Adam Elga for their insights into the problem.

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References:

Elga, A. (2000). Self-locating belief and the Sleeping Beauty problem. Analysis, 60(2), 143-147. - https://ve42.co/Elga2000

Lewis, D. (2001). Sleeping beauty: reply to Elga. Analysis, 61(3), 171-176. - https://ve42.co/Lewis2001

Winkler, P. (2017). The sleeping beauty controversy. The American Mathematical Monthly, 124(7), 579-587. - https://ve42.co/Winkler2017

Titelbaum, M. G. (2013). Ten reasons to care about the Sleeping Beauty problem. Philosophy Compass, 8(11), 1003-1017. - https://ve42.co/Titelbaum2013

Mutalik, P. (2016). Solution: ‘Sleeping Beauty’s Dilemma’, Quanta Magazine - https://ve42.co/MutalikQ2016

Rec.Puzzles - Some “Sleeping Beauty” Postings - https://ve42.co/SBRecPuzzles

The Sleeping Beauty Paradox, Statistics SE - https://ve42.co/SBPSSE

The Sleeping Beauty Problem, Reddit - https://ve42.co/SBPReddit

Sleeping Beauty paradox explained, GameFAQs - https://ve42.co/SBPGameFAQ

The Sleeping Beauty Problem, Physics Forums - https://ve42.co/SBPPhysicsForums

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Special thanks to our Patreon supporters:
Tj Steyn, Meg Noah, Bernard McGee, KeyWestr, Elliot Miller, Brian Busbee, Jerome Barakos, M.D., Amadeo Bee, TTST, Balkrishna Heroor, Chris LaClair, John H. Austin, Jr., Eric Sexton, john kiehl, Anton Ragin, Benedikt Heinen, Diffbot, Gnare, Dave Kircher, Burt Humburg, Blake Byers, Evgeny Skvortsov, Meekay, Bill Linder, Paul Peijzel, Josh Hibschman, Mac Malkawi, Mike Schneider, jim buckmaster, Juan Benet, Ubiquity Ventures, Richard Sundvall, Lee Redden, Stephen Wilcox, Marinus Kuivenhoven, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi.

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Written by Emily Zhang, Derek Muller, Tamar Lichter Blanks
Edited by Fabio Albertelli
Animation by Ivy Tello, Fabio Albertelli, Jakub Misiek
Additional video/photos supplied by Getty Images & Pond5
Music from Epidemic Sound
Thumbnail by Ignat Berbeci
Produced by Derek Muller, Petr Lebedev, Emily Zhang

In this lab, they use different flow visualization techniques to help detect contraband, residues, and develop trace particle detection methods. Part of this video was sponsored by Caseta by Lutron. Find out more at https://casetawireless.com/veritasium

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Thanks to Rich Press and NIST for the great visit.
Thanks to Matt Staymates for taking us around his lab and showing us the fascinating research being done with flow visualization.
You can check out all the cool work going on at NIST here: https://www.nist.gov/

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References:

Staymates, M.E., (2020). My Stay-at-Home Lab Shows How Face Coverings Can Slow the Spread of Disease. NIST. – https://ve42.co/FaceMaskNIST

Staymates, M. E., et al. (2016). Biomimetic sniffing improves the detection performance of a 3D printed nose of a dog and a commercial trace vapor detector. Scientific reports, 6(1), 1-10. – https://ve42.co/Staymates2016

NIST. (2022). Surface and Trace Chemical Analysis Group. – https://ve42.co/NISTgroup

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Special thanks to our Patreon supporters:
Bernard McGee, James Sanger, Elliot Miller, Brian Busbee, Jerome Barakos M.D., Amadeo Bee, TTST, Balkrishna Heroor, Chris LaClair, John H. Austin Jr., OnlineBookClub.org, Eric Sexton, John Kiehl, Diffbot, Gnare, Dave Kircher, Burt Humburg, Blake Byers, Evgeny Skvortsov, Meekay, Bill Linder, Paul Peijzel, Josh Hibschman, Mac Malkawi, Mike Schneider, John Bauer, Jim Buckmaster, Juan Benet, Sunil Nagaraj, Richard Sundvall, Lee Redden, Stephen Wilcox, Marinus Kuivenhoven, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi

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Written by Derek Muller and Emily Zhang
Edited by Trenton Oliver
Animation by Ivy Tello
Filmed by Derek Muller, Raquel Nuno, Trenton Oliver, and Emily Zhang
Additional video/photos supplied by Pond5 & Getty Images
Music from Epidemic Sound
Thumbnail by Ignat Berbeci
Produced by Derek Muller, Petr Lebedev, and Emily Zhang

Why do droplets of food coloring attract, repel, and chase each other?
Snatoms molecular models: http://igg.me/at/snatoms
More about this topic: http://wke.lt/w/s/VRjRQ

Original paper on droplets: http://stanford.edu/~manup/doc....s/Cira_DancingDrople
Marangoni Flow: http://web.mit.edu/2.21/www/Le....c-notes/Surfacetensi
Surface Energy: https://itf.fys.kuleuven.be/~j....oi/papers/Wetting%20

Filming and master pipetting by Raquel Nuno
Research and writing by Aaron White

Increasing entropy is NOT the only process that's asymmetric in time.
Check out the book: http://WeHaveNoIdea.com
This video was co-written by Daniel Whiteson and Jorge Cham
You can also check out PhD Comics: http://phdcomics.com


Special thanks to Patreon supporters:
Tony Fadell, Donal Botkin, Michael Krugman, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen, Joshua Abenir

Support Veritasium on Patreon: http://ve42.co/patreon

Original paper on parity violation by the weak force by Lee and Yang:
http://www.physics.utah.edu/~b....elz/phys5110/PhysRev

More on B-meson oscillations and time reversal violation:
Physics World Article: http://ve42.co/TimeReversal
Original paper: https://arxiv.org/pdf/1410.1742.pdf
https://en.wikipedia.org/wiki/B_meson

Physics consultant: Prof. Stephen Bartlett

Studio filming by Raquel Nuno

The merging of two neutron stars was detected by gravitational waves and then by telescopes in all parts of the electromagnetic spectrum. This is a historic detection as it demonstrates:
- the first gravitational waves detected from inspiraling neutron stars
- the first joint observation by gravitational wave and electromagnetic wave astronomy
- identification of a gamma ray burst in conjunction with merging neutron stars
- how gravitational waves and gamma rays can be used together to locate their source

All evidence so far indicates that the data support General Relativity.

Special thanks to Patreon supporters:
Tony Fadell, Donal Botkin, Curational, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen, Corvi

Support Veritasium on Patreon: http://ve42.co/patreon

Graphics from:
Jets and Debris from a Neutron Star Collision
This animation captures phenomena observed over the course of nine days following the neutron star merger known as GW170817. They include gravitational waves (pale arcs); a near-light-speed jet that produced gamma rays (magenta); expanding debris from a "kilonova" that produced ultraviolet (violet), optical and infrared (blue-white to red) emission; and, once the jet directed toward us expanded into our view from Earth, X-rays (blue).
Credit: NASA's Goddard Space Flight Center/CI Lab

Virgo Helps Localize Gravitational-Wave Signals
Sky localizations of gravitational-wave signals detected by LIGO beginning in 2015 (GW150914, LVT151012, GW151226, GW170104), and, more recently, by the LIGO-Virgo network (GW170814, GW170817). After Virgo came online in August 2017, scientists were better able to localize the gravitational-wave signals. The background is an optical image of the Milky Way. The localizations of GW150914, LVT151012, and GW170104 wrap around the celestial sphere, so the sky map is shown with a translucent dome.
Credit: LIGO/Virgo/NASA/Leo Singer (Milky Way image: Axel Mellinger)

Variety of Gravitational Waves and a Chirp
The signal measured by LIGO and Virgo from the neutron star merger GW170817 is compared here to previously detected binary black hole mergers. All signals are shown starting at 30 Hertz, and the progression of GW170817 is shown in real time, accompanied by its conversion to audio heard at the end of the movie. GW170817 was observable for more than 30 times longer than any previous gravitational-wave signal.
Credit: LIGO/University of Oregon/Ben Farr

LIGO is funded by the NSF, and operated by Caltech and MIT, which conceived of LIGO and led the Initial and Advanced LIGO projects. Financial support for the Advanced LIGO project was led by the NSF with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council) and Australia (Australian Research Council) making significant commitments and contributions to the project.

More than 1,200 scientists and some 100 institutions from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration and the Australian collaboration OzGrav. Additional partners are listed at http://ligo.org/partners.php

The Virgo collaboration consists of more than 280 physicists and engineers belonging to 20 different European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; eight from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; two in the Netherlands with Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with the University of Valencia; and the European Gravitational Observatory, EGO, the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN, and Nikhef.

Europa Clipper is looking for signs of alien life in a very deadly place. Head to http://80000hours.org/veritasium to start planning a career that can help change the world for the better.

A massive thank you to Dr. Robert Pappalardo for his expertise and time.

A huge thank you to Gretchen McCartney and Cynthia B. Phillips at NASA JPL for their help.

For more on hydrothermal vents, check out NaturalWorldFacts on YouTube - @NaturalWorldFacts

00:00 ATTEMPT NO LANDING.
01:06 Jupiter’s deadly radiation belts
03:56 Europa’s secret
06:15 Why Europa isn’t completely frozen
08:03 Effects of tidal flexing
09:13 Why alien life could exist
10:39 How Europa Clipper detects signs of life
11:34 Why not Enceladus?
13:01 Europa Clipper’s instruments
15:13 Launch date and first results

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Special thanks to our Patreon supporters! Join the community to help us keep our videos free, forever: https://ve42.co/PatreonDE

Adam Foreman, Albert Wenger, Anton Ragin, Ayush Agrawal, Balkrishna Heroor, Bertrand Serlet, Bill Linder, Blake Byers, Bruce, Dave Kircher, David Johnston, Evgeny Skvortsov, Garrett Mueller, Gnare, gpoly, I. H., Jack Cuprill, John H. Austin, Jr., john kiehl, Juan Benet, KeyWestr, Kirill Shore, Kyi, Lee Redden, Marinus Kuivenhoven, Matthias Wrobel, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, Reed Spilmann, Richard Sundvall, Sam Lutfi, Shiroyasha, Tj Steyn, TTST, Ubiquity Ventures and 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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References:
Europa Clipper via Wikipedia - https://ve42.co/ECWiki
Magnetosphere of Jupiter via Wikipedia - https://ve42.co/JupiterMagWiki
Europa Clipper (2024) via Nasa.gov - https://ve42.co/ECNasa
Extraterrestrial Cycloids - Why Are They on Europa? via minutephysics on YouTube - https://ve42.co/MinPhysCycloid
Hand, K. P. & Carlson, R. W. (2015). Europa’s surface color suggests an ocean rich with sodium chloride. Geophysical research letters - https://ve42.co/Carlson2015
Dalton, J. B. et al. (2003). Near-Infrared Detection of Potential Evidence for Microscopic Organisms on Europa. Astrobiology - https://ve42.co/Dalton2003
Europa Clipper: Exploring Jupiter's Ocean World (2024, May 24) via Youtube - https://ve42.co/PappalardoLec
Carr, M., Belton, M., Chapman, C. et al. (1998). Evidence for a subsurface ocean on Europa. Nature 391, 363–365 - https://ve42.co/Carr1998
New Findings Support Prospect of Life on Jupiter’s Moon Europa (2024) via Nasa.gov - https://ve42.co/NasaEuropaLife
Meitzler, R., Jun, I., Blase, R. et al. (2023). Investigating Europa’s Radiation Environment with the Europa Clipper Radiation Monitor. Space Sci Rev 219, 61 - https://ve42.co/Meitzler2023

#europaclipper

Images & Video:
2010: The Year We Make Contact - https://ve42.co/2010Contact
CGI animations via NASA - https://ve42.co/NasaCGI
NASA Eyes on the Solar System - https://ve42.co/NasaEyes
Jupiter's magnetosphere via Chandra X-Ray Center - https://ve42.co/JupiterMagChandra
Io's Volcanoes via BBC Earth Science - https://ve42.co/IoBBCEarth
Clipper ships via Wikipedia - https://ve42.co/ClipperShipWiki
Various moon images via NASA - https://ve42.co/NasaMoons
Hydrothermal vent animation from NaturalWorldFacts - https://ve42.co/NWFVentAnims
Hydrothermal vent footage by Monterey Bay Aquarium Research Institute - https://ve42.co/ARIVent
Snotbot footage from VICE News - https://ve42.co/SnotBotVice
Plate tectonics on Europa by Noah Kroese - https://ve42.co/KroeseTectonics
JUICE CGI animations via ESA - https://ve42.co/JUICECGIESA
Arthur C. Clarke photo via ITU Pictures under the CC 2.0 license - https://ve42.co/ClarkePhoto

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Directed by Gregor Čavlović
Written by Gregor Čavlović and Derek Muller
Edited by Jack Saxon
Animated by Mike Radjabov, Fabio Albertelli, and Jack Saxon
Illustrated by Jakub Misiek
Filmed by Derek Muller, Petr Lebedev and Gregor Čavlović
Additional research by Gabriel Strong
Produced by Derek Muller, Gregor Čavlović, Rob Beasley Spence, Tori Brittain, Luke Lewis, Barbara Abraul, Gabriel Strong, Petr Lebedev, and Casper Mebius

Thumbnail contributions by Ren Hurley, Peter Sheppard, and Jakub Misiek

Additional video/photos supplied by Getty Images and Storyblocks
Music from Epidemic Sound

A planet has been predicted to orbit the sun with a period of 10,000 years, a mass 5x that of Earth on a highly elliptical and inclined orbit. What evidence supports the existence of such a strange object at the edge of our solar system?

Huge thanks to:
Prof. Konstantin Batygin, Caltech
Prof. David Jewitt, UCLA

I had heard about Planet 9 for a long time but I wondered what sort of evidence could support the bold claim: a planet at the very limits of our ability to detect one, so far out that its period is over 60 times that of Neptune. The planet 9 hypothesis helps explain clustering of orbits of distant Kuiper belt objects. It also explains how some of these objects have highly inclined orbits - up to 90 degrees relative to the plane of the solar system. Some are orbiting in reverse. Plus their orbits are removed from the orbit of Neptune, the logical option for a body that could have ejected them out so far. The fact that the perihelion is so far out suggests another source of gravity was essential for their peculiar orbits.

Special Thanks to Patreon Supporters:
Alfred Wallace, Arjun Chakroborty, Bryan Baker, Chris Vargas, Chuck Lauer Vose, DALE HORNE, Donal Botkin, Eric Velazquez, halyoav, James Knight, Jasper Xin, Joar Wandborg, Kevin Beavers, kkm, Leah Howard, Lyvann Ferrusca, Michael Krugman, Mohammed Al Sahaf, Noel Braganza, Pindex, Ron Neal, Sam Lutfi, Stan Presolski, Tige Thorman

Music from http://epidemicsound.com "Observations - From Now On" "Magnified XY"

How do sewing machines actually work? Get your first month of KiwiCo FREE at https://www.kiwico.com/veritasium

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

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A huge thanks to Prof. Andy Ruina for suggesting this video topic, guiding us in the research, and giving deeply insightful notes.

Massive thanks to Noah Johnson and Tina Vines for teaching Derek how to chain-stitch, and letting us shoot with your embroidery machine! Please check out https://www.instagram.com/stitchrite and https://www.instagram.com/tina_vines if you're interested in seeing more of their gorgeous chain stitch embroidery.

Thanks to Denny Stanley and the whole crew at Las Vegas Props for building the large replica model of the sewing machine. https://www.vegasprops.net

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References:
Parton, J. (1870). History of the Sewing-machine. Howe Machine Company, No. 38, N. Charles St.. -- https://ve42.co/Patron1870

Gregory, J. M. (2006). A History of the Sewing Machine to 1880. Transactions of the Newcomen Society, 76(1), 127-144. -- https://ve42.co/Gregory2006

How America Spends Money: 100 Years In the Life of the Family Budget, The Atlantic -- https://ve42.co/Budget1

Buckman, J. (2016). Unraveling the Threads: The Life, Death and Resurrection of the Singer Sewing Machine Company, America’s First Multi-National Corporation. Dog Ear Publishing.

Lewton, F. L. (1930). The servant in the house: a brief history of the sewing machine (Vol. 3056). US Government Printing Office. -- https://ve42.co/Lewton1930

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Special thanks to our Patreon supporters:
Adam Foreman, Anton Ragin, Balkrishna Heroor, Bernard McGee, Bill Linder, Burt Humburg, Chris Harper, Dave Kircher, Diffbot, Evgeny Skvortsov, Gnare, John H. Austin, Jr., john kiehl, Josh Hibschman, Juan Benet, KeyWestr, Lee Redden, Marinus Kuivenhoven, Max Paladino, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, Richard Sundvall, Sam Lutfi, Stephen Wilcox, Tj Steyn, TTST, Ubiquity Ventures

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Directed by Petr Lebedev
Written by Petr Lebedev, Derek Muller, Felicity Nelson
Edited by Trenton Oliver
Animated by Mike Radjabov, Fabio Albertelli and Jakub Misiek
Filmed by Derek Muller, Raquel Nuno, Gene Nagata and Taylor Cody
Additional Research by Gregor Čavlović
Produced by Petr Lebedev, Han Evans, and Derek Muller
Additional video/photos supplied by Getty Images and Storyblocks
Music from Epidemic Sound

There is an entire branch of math simply devoted to knots – and it has changed the world. We’ll rope you in. Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.

Special thanks to our Patreon supporters! Join the community to help us keep our videos free, forever:
https://ve42.co/PatreonDEB

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Huge thanks to Prof. Colin Adams for his excellent help guiding us through the world of knots.
Many thanks to Prof. Doug Smith, Dorian Raymer, Prof. David Leigh, and Prof. Dorothy Buck for helping us understand applications of knot theory.
Many thanks to Prof. Dan Silver & Prof. Jim Hoste for speaking with us about the history and tabulation of knots.

If you want to learn more about knots and play with them yourself, check out:
The amazing KnotPlot tool — https://knotplot.com/. Thanks to Rob Scharein for providing technical help as well!
A table of knots and all their invariants — https://knotinfo.math.indiana.edu/
The Knot Atlas for general info on knots — http://katlas.org/wiki/Main_Page

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Knot Theory Video References – https://ve42.co/KnotTheoryRefs

Images & Video:
Alexander Cutting the Gordian Knot by Donato Creti via Fine Art America - https://ve42.co/GordianCut
Indus Valley tablet via Quora - https://ve42.co/IndusValley
Pages from the Book of Kells via National Trust of Scotland - https://ve42.co/BookOfKells
Medieval Celtic designs from @thebookofkellsofficial via Instagram - https://ve42.co/KellsInsta
Chinese knotwork by YWang9174 via Wikimedia Commons - https://ve42.co/Panchang
Quipu cords by Pi3.124 via Wikimedia Commons - https://ve42.co/Quipu
Borromeo heraldry via Terre Borromeo - https://ve42.co/Borromeo
Birman/Jones letter via Celebratio Mathematica - https://ve42.co/JonesBirman
Molecular trefoil knot by M stone via Wikimedia Commons - https://ve42.co/TrefoilMolecule
X-ray structure of trefoil knot by Ll0103 via Wikimedia Commons - https://ve42.co/XrayTrefoil
Bacteria animation from Your Body's Molecular Machines by Drew Berry via the Walter and Eliza Hall Institute of Medical Research - http://wehi.tv
Topoisomerase and knots from Orlandini et al. Synergy of topoisomerase. PNAS, vol. 116, no. 17, 2019, pp. 8149–8154. – https://ve42.co/Orlandini2019
KnotProt 2.0: A database of proteins with knots and slipknots - https://ve42.co/Knotprot

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Special thanks to our Patreon supporters:
Anton Ragin, Balkrishna Heroor, Bernard McGee, Bill Linder, Burt Humburg, Dave Kircher, Diffbot, Evgeny Skvortsov, Gnare, Jesse Brandsoy, John H. Austin, Jr., john kiehl, Josh Hibschman, Juan Benet, KeyWestr, Lee Redden, Marinus Kuivenhoven, Mario Bottion, MaxPal, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, Richard Sundvall, Sam Lutfi, Stephen Wilcox, Tj Steyn, TTST, Ubiquity Ventures

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Directed by Emily Zhang
Written by Emily Zhang and Derek Muller
Edited by Trenton Oliver
Animated by Fabio Albertelli, Ivy Tello, Jakub Misiek, and Mike Radjabov
Filmed by Derek Muller, Raquel Nuno, and Emily Zhang
Produced by Emily Zhang, Han Evans, and Derek Muller

Thumbnail by Ignat Berbeci and Mike Radjabov
Additional video/photos supplied by Getty Images and Pond5
Music from Epidemic Sound

The misconception is that electrons carry potential energy around a complete conducting loop, transferring their energy to the load. This video was sponsored by Caséta by Lutron. Learn more at https://Lutron.com/veritasium

Further analysis of the large circuit is available here: https://ve42.co/bigcircuit

Special thanks to Dr Geraint Lewis for bringing up this question in the first place and discussing it with us. Check out his and Dr Chris Ferrie’s new book here: https://ve42.co/Universe2021

Special thanks to Dr Robert Olsen for his expertise. He quite literally wrote the book on transmission lines, which you can find here: https://ve42.co/Olsen2018

Special thanks to Dr Richard Abbott for running a real-life experiment to test the model.

Huge thanks to all of the experts we talked to for this video -- Dr Karl Berggren, Dr Bruce Hunt, Dr Paul Stanley, Dr Joe Steinmeyer, Ian Sefton, and Dr David G Vallancourt.

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References:
A great video about the Poynting vector by the Science Asylum: https://youtu.be/C7tQJ42nGno

Sefton, I. M. (2002). Understanding electricity and circuits: What the text books don’t tell you. In Science Teachers’ Workshop. -- https://ve42.co/Sefton

Feynman, R. P., Leighton, R. B., & Sands, M. (1965). The feynman lectures on physics; vol. Ii, chapter 27. American Journal of Physics, 33(9), 750-752. -- https://ve42.co/Feynman27

Hunt, B. J. (2005). The Maxwellians. Cornell University Press.

Müller, R. (2012). A semiquantitative treatment of surface charges in DC circuits. American Journal of Physics, 80(9), 782-788. -- https://ve42.co/Muller2012

Galili, I., & Goihbarg, E. (2005). Energy transfer in electrical circuits: A qualitative account. American journal of physics, 73(2), 141-144. -- https://ve42.co/Galili2004

Deno, D. W. (1976). Transmission line fields. IEEE Transactions on Power Apparatus and Systems, 95(5), 1600-1611. -- https://ve42.co/Deno76

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Special thanks to Patreon supporters: Luis Felipe, Anton Ragin, Paul Peijzel, S S, Benedikt Heinen, Diffbot, Micah Mangione, Juan Benet, Ruslan Khroma, Richard Sundvall, Lee Redden, Sam Lutfi, MJP, Gnare, Nick DiCandilo, Dave Kircher, Edward Larsen, Burt Humburg, Blake Byers, Dumky, Mike Tung, Evgeny Skvortsov, Meekay, Ismail Öncü Usta, Crated Comments, Anna, Mac Malkawi, Michael Schneider, Oleksii Leonov, Jim Osmun, Tyson McDowell, Ludovic Robillard, Jim buckmaster, fanime96, Ruslan Khroma, Robert Blum, Vincent, Marinus Kuivenhoven, Alfred Wallace, Arjun Chakroborty, Joar Wandborg, Clayton Greenwell, Michael Krugman, Cy 'kkm' K'Nelson,Ron Neal


Written by Derek Muller and Petr Lebedev
Animation by Mike Radjabov and Ivy Tello
Filmed by Derek Muller and Emily Zhang
Footage of the sun by Raquel Nuno
Edited by Derek Muller
Additional video supplied by Getty Images
Music from Epidemic Sound
Produced by Derek Muller, Petr Lebedev and Emily Zhang

A launch mishap led to the best experimental confirmation of gravitational redshift. Get a free audiobook with a 30-day trial of Audible: http://audible.com/VERITASIUM or text VERITASIUM to 500500

Huge thanks to
Dr. Pacome Delva: https://ve42.co/pacome
Dr. Sven Herrmann: https://ve42.co/sven
Gravitational Redshift Test Using Eccentric Galileo Satellites: https://ve42.co/GRtest

Disclaimer: It is arguable what is THE best test of general relativity because there are different ways to test the theory. This is the best confirmation of gravitational redshift, which is one of the three original tests proposed by Einstein.

Special thanks to Patreon supporters:
Donal Botkin, James M Nicholson, Michael Krugman, Nathan Hansen, Ron Neal, Stan Presolski, Terrance Shepherd

Animations and editing by Alan Chamberlain

Music from http://epidemicsound.com "Subtle Substitutes 2" "A sound Foundation 1" "Cell Research 1" "Particle Attraction 1"

Corn flour blown through a funnel produces an excellent fireball. This both looks cool and demonstrates some interesting science. In any chemical reaction, the reactants must mix with each other significantly in order to increase the rate of reaction. Here we demonstrate that corn flour on a spoon burns slowly, but blown from a funnel, the reaction is dramatic and violent. This is because the surface area where the reaction can occur is greatly increased.

HD Slinky Slow-mo http://bit.ly/TRa4sE
How to make solid nitrogen http://bit.ly/RqPw8l
Levitating BBQ http://bit.ly/SWgOWh
Electric Flame http://bit.ly/Q3enCb

As always, if you are planning to recreate this experiment, make sure you have appropriate supervision and take necessary precautions.

How do QR codes work? The checkerboard patterns taking over the world, demystified. Go to https://Saily.com/veritasium and use the code ‘veritasium’ to get an exclusive 15% off your first purchase.

Special thanks to Mashiro Hara and Yuki Watanabe.

00:00 I was wrong
00:49 How Morse Code revolutionized communication
03:57 How barcodes work
10:34 How QR codes store information
18:16 Why damaged QR codes still work
29:54 Why are QR codes so common?
31:21 How safe are QR codes?
32:25 The future of QR codes

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

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References: https://ve42.co/QRCodeRefs


Images & Video:
1940’s grocery store - H.I.C - https://ve42.co/1940sShop
Why Americans Are Obsessed With Peanut Butter via Youtube - https://ve42.co/PeanutButter1
Jif Peanut Butter 90s Commercial (1998) via Youtube - https://ve42.co/PeanutButter2
Vericode Symbol via Youtube - https://ve42.co/VericodeSymbol
Oreo introduces Sour Patch Kids cookies via YouTube - https://ve42.co/OreaSour
BSE - Changes in Behaviour via YouTube - https://ve42.co/BSE
QR Code with Drones | Firefly Drone Show via YouTube - https://ve42.co/DroneQRCode
Damaged barcode 1 by christiaangpr via Reddit - https://ve42.co/DamagedBarcode1
Damaged barcode 2, Midcom service group https://ve42.co/DamagedBarcode2
Oskana, G and Petkova, A. (2020 July 1). Testing a nano-barcodes marking technology for identification and protection of the mechanical products, Fig. 1 - https://ve42.co/MatrixCodes
NASA Celebrates 40 Years of the Voyager Mission via Nasa.gov - https://ve42.co/Voyager40Yr
Apollo footage via Nasa.gov - https://ve42.co/ApolloFootage
Snake in a QR code by MattKC via mattkc.com - https://ve42.co/SnakeQR
Scratched CD by Ice3yes via Reddit - https://ve42.co/ScratchedCD
Alfred Vail Portrait via si.edu - https://ve42.co/AlfredVail
Bernard Silver Portrait vai invent.org - https://ve42.co/BernardSilver
Norman Joseph Woodland Portrait via usatoday.com https://ve42.co/NormanWoodland
Masahiro Hara portrait via denso.com https://ve42.co/MasahiroPhoto
Cooke and Wheatstone telegraph patents via Wikipedia:
https://ve42.co/TelegraphPatent1
https://ve42.co/TelegraphPatent2
https://ve42.co/TelegraphPatent3
https://ve42.co/TelegraphPatent4
https://ve42.co/TelegraphPatent5
https://ve42.co/TelegraphPatent6
5 needle telegraph via cachesleuth.com- https://ve42.co/NeedleTelegraph

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Special thanks to our Patreon supporters:

Adam Foreman, Albert Wenger, Anton Ragin, Balkrishna Heroor, Bertrand Serlet, Bill Linder, Blake Byers, Bruce, Dave Kircher, David Johnston, Evgeny Skvortsov, Garrett Mueller, Gnare, I. H., Jack Cuprill, John H. Austin, Jr., Juan Benet, KeyWestr, Kirill Shore, Kyi, Lee Redden, Marinus Kuivenhoven, Matthias Wrobel, Meekay, Michael Krugman, Orlando Bassotto, Paul Peijzel, Reed Spilmann, Richard Sundvall, Sam Lutfi, TTST, Tj Steyn, Ubiquity Ventures, gpoly, john kiehl, meg noah, wolfee

▀▀▀
Directed by Sumeet Kulkarni
Written by Sumeet Kulkarni and Derek Muller
Edited by Peter Nelson and Luke Molloy
Animated by David Szakaly, Fabio Albertelli, James Finnemore, Ivy Tello
Illustrations by Jakub Misiek, Emma Wright
Filmed by Derek Muller and Raquel Nuno
Additional Research by Gabriel Strong
Produced by Sumeet Kulkarni, Derek Muller, Rob Beasley Spence, Emily Lazard, Tori Brittain, Emily Zhang

Thumbnail contributions by Peter Sheppard, Ren Hurley, David Szakaly, Gregor Čavlović, Raquel Nuno
Additional video/photos supplied by Getty Images and Story Blocks
Music from Epidemic Sound

Mars InSight will be the first to detect seismic activity on Mars’ surface, first to measure rate of heat transmitted from interior, first to dig nearly 5m down, first to measure magnetic fields on Mars’ surface, and first to use a robotic arm to place instruments on the surface of Mars (assuming it lands of course…)

If you want to watch the InSight landing “live” (with 4-minute speed of light time delay), go to: https://ve42.co/insight

Special thanks to Patreon supporters:
Donal Botkin, James M Nicholson, Michael Krugman, Nathan Hansen, Ron Neal, Stan Presolski, Terrance Shepherd

Animations courtesy of NASA

Script and Filming with Raquel Nuno

Editing and graphics by Ignat Berbeci

This is a video about the most famous problem in Game Theory, the Prisoner’s Dilemma. Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.

Special thanks to our Patreon supporters! Join the community to help us keep our videos free, forever:
https://ve42.co/PatreonDEB

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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A massive thank you to Prof. Robert Axelrod and Prof. Steven Strogatz for their expertise and time.

To read more about Prof. Axelrod’s Passion for Cooperation visit: https://ve42.co/Axelrod2023

A massive thanks to the wonderful Nicky Case. Nicky’s “The Evolution of Trust” game was a huge inspiration for this video. We highly recommend you play this excellent game yourself, over at: https://ncase.me/trust/

A huge thank you to those who helped us understand and fact check different parts of this topic - Dr. Christian Hilbe, Dr. Vincent Knight, Dr. Jelena Grujic, Prof. Andreas Diekmann, and Dr. Alexander Stewart.

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References:
Excellent game on the evolution of trust by Nicky Case - https://ve42.co/Case2023
Summary of Axelrod’s work by This Place - https://www.youtube.com/watch?v=BOvAbjfJ0x0
How to outsmart the Prisoner’s Dilemma by TED-Ed - https://www.youtube.com/watch?v=emyi4z-O0ls&pp=ygUScHJpc29uZXIncyBkaWxlbW1h
Tit for Tat by radiolab - https://ve42.co/T4T
The Golden Rule by radiolab - https://ve42.co/GoldenRule
Axelrod, R. (1984). The Evolution of Cooperation.
Dawkins, R. (2016). The selfish gene. Oxford university press.
Poundstone, W. (1992). Prisoner's Dilemma. William Poundstone.
Nowak, M. A., & Highfield, R. (2011). Supercooperators. Edinburgh: Canongate.
Binmore, K. (2007). Game theory: a very short introduction. OUP Oxford.
Northrup, L. & Rock, D. (1966). The Detection of Joe I. - https://ve42.co/JOE1
Prisoner’s dilemma, Wikipedia - https://ve42.co/WikiPD
Prisoner’s Dilemma, Stanford - https://ve42.co/StanfordPD
Flood, M. M. (1952). Some experimental games. - https://ve42.co/Flood1952
Historical nuclear weapons stockpiles, Wikipedia - https://ve42.co/WikiNWS
Goodwin, I. (1998). The Price of Victory in Cold War - https://ve42.co/Goodwin1998
Cold war: How it happened. - https://ve42.co/CW2014
Axelrod, R. (1980). Effective choice in the prisoner's dilemma. Journal of conflict resolution, 24(1), 3-25. - https://ve42.co/Axelrod1980a
Axelrod, R. (1980). More effective choice in the prisoner's dilemma. Journal of conflict resolution, 24(3), 379-403. - https://ve42.co/Axelrod1980b
Axelrod, R., & Hamilton, W. D. (1981). The evolution of cooperation. science, 211(4489), 1390-1396. https://ve42.co/Axelrod1981
Stanislav Petrov, Wikipedia - https://ve42.co/WikiSP
Wu, J., & Axelrod, R. (1995). How to cope with noise in the iterated prisoner's dilemma. Journal of Conflict resolution, 39(1), 183-189. - https://ve42.co/Wu1995
INF Treaty - https://ve42.co/INF
START Treaties - https://ve42.co/START
START I, Wikipedia - https://ve42.co/WikiSTART


Images & Video:
RAND Historical images via rand.org - https://ve42.co/RAND
Golden Balls - https://www.youtube.com/watch?v=S0qjK3TWZE8
Zotti, G., et al. (2021). The Simulated Sky: Stellarium for Cultural Astronomy Research - https://ve42.co/Stellarium
Newspapers from 1980s via Newspapers.com – https://ve42.co/Newspapers
Decommisioned nuke image via The Moscow Times - https://ve42.co/MT2012
Soviet inspection image via Bulletin of the Atomic Scientists - https://ve42.co/Krzyzaniak2019
Decommissioning nuclear weapon via ShareAmerica - https://ve42.co/Kaufman2014


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Special thanks to our Patreon supporters:
Adam Foreman, Amadeo Bee, Anton Ragin, Balkrishna Heroor, Bernard McGee, Bill Linder, Burt Humburg, Dave Kircher, Diffbot, Evgeny Skvortsov, Gnare, Jesse Brandsoy, John H. Austin, Jr., john kiehl, Josh Hibschman, Juan Benet, KeyWestr, Lee Redden, Marinus Kuivenhoven, Mario Bottion, Max Maladino, Meekay, meg noah, Michael Krugman, Paul Peijzel, Richard Sundvall, Sam Lutfi, Stephen Wilcox, Tj Steyn, TTST, Ubiquity Ventures


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Directed by Casper Mebius
Written by Casper Mebius, Derek Muller, Petr Lebedev, and Ashley Hamer
Additional research and fact checking by Gregor Čavlović and Will Wood
Edited by Peter Nelson
Animated by Fabio Albertelli, Ivy Tello and Alondra Vitae
Illustrations by Jakub Misiek
Filmed by Derek Muller
Produced by Casper Mebius, Derek Muller, Gregor Čavlović and Han Evans

Additional video/photos supplied by Getty Images
Music from Epidemic Sound
Thumbnail by Peter Sheppard

How a helicopter built of phone parts survived Mars for 3 years. Use code veritasium at https://incogni.com/veritasium to get an exclusive 60% off an annual Incogni plan.

Try Snatoms! A molecular modelling kit I invented where the atoms snap together.
https://ve42.co/SnatomsV

Correction:
0:12, we say that ingenuity is 680g which is its weight on Mars. On Earth however, it weighs around 1800g.

Clarifications:
- A Patreon supporter named Zeus pointed out that we were wrong about Perseverance's/Ingenuity's position on Mars. It is in the Northern Hemisphere and hence Mars would be getting closer to the Sun as it goes into winter.
- Ingenuity was on Mars for 1004 Earth days.

Sign up to the Veritasium newsletter for weekly science updates - https://ve42.co/Newsletter

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A massive thank you to the team at JPL and especially Teddy Tzanetos, Travis Brown, Håvard Grip and DC Agle

Check out Astrum's video on Mars - https://www.youtube.com/watch?v=b7mjp7MDx_w

▀▀▀
0:00 How Did Ingenuity Get To Mars?
3:23 Better Results, Bigger Expectations
6:15 Wobblecopter
7:48 Dust On Mars
9:41 What Is The Temperature On Mars?
11:54 Wake-Up Call
13:41 Android To The Rescue
16:22 Cosmic Rays
20:53 Dune and The Crash
25:26 The Next Generation

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References:

Ingenuity Mars Helicopter - NASA Science via science.nasa.gov - https://ve42.co/marsheli2
Ingenuity (helicopter) via Wikipedia - https://ve42.co/wikiheli
Mars Facts | NASA Mars Exploration via science.nasa.gov - https://ve42.co/marsfacts
Inside the Ingenuity Helicopter Teamwork on Mars via insideunmannedsystems.com - https://ve42.co/marscrew
Ingenuity Adapts for Mars Winter Operations via science.nasa.gov - https://ve42.co/marswinter
Ingenuity Is Doing Surprisingly Well via www.universetoday.com - https://ve42.co/marswell
Remember NASA's Little Mars Copter? It's Still Going Strong via www.sciencealert.com - https://ve42.co/marsstrong
How Far Away Is Mars? via www.space.com - https://ve42.co/marsdist
Mars Cameras via science.nasa.gov - https://ve42.co/marsorb
Mars Exploration Meeting Documentation via www.hou.usra.edu - https://ve42.co/marsmeet
Ingenuity Quick Facts via www.jpl.nasa.gov - https://ve42.co/marsquick
Flight 14 Delayed via science.nasa.gov - https://ve42.co/marsspin

Additional References - https://ve42.co/MarsAdRefs

Images & Video:

Images and video from Perseverance and Ingenuity missions supplied by the NASA Jet Propulsion Laboratory

Matthias (3 axis accelerometer, 3 axis gyroscope) https://youtu.be/yqFfmwVufMo?si=IoCj32PeVNZ4VJ-F
Veritasium. https://youtu.be/ty9QSiVC2g0?si=Gb48I-YjADPbPUsL
The Limiting Factor
https://youtu.be/4-1psMHSpKs?si=LF1jfLLNsBwRfwkB
NASA Jet Propulsion Laboratory. https://youtu.be/xsUtq8PwZpQ?si=xOC91fdoSHdJndgx
VideoFromSpace. https://youtu.be/Kb0Pc22N6w4?si=4uSUetsSUKFTStme
NASA Jet Propulsion Laboratory. https://youtu.be/qMbHE_VXI-8?si=TNePbTRpcN3oLEVJ
Veritasium. https://youtu.be/GhsZUZmJvaM?si=IIY0uuDrT-LzY5bI
Sighawke. https://youtu.be/OdKAW_0ENPU?si=18ZXXll3wSMj_Ex3
NASA Jet Propulsion Laboratory. https://youtu.be/thk4Rha-fTk?si=_elC6Iqm1uaSjEFX
NASA Jet Propulsion Laboratory. https://youtu.be/PFbzEM8PzHE?si=LmO71EVFqBAn6NEw
NASA Jet Propulsion Laboratory. https://youtu.be/ia6S1jZmwWc?si=aAFC-BEmGwHIIqH7
JPL Raw. https://youtu.be/uz4GaAE7OMQ?si=7084_GDkrGnSSVTy
NASA Jet Propulsion Laboratory. https://youtu.be/U7DFnNimSfw?si=JgwO2SNU9HXf3GIa
Apex Clips. https://youtu.be/NttUBB98zg4?si=j1OEQD1VBONTEEPI
Veritasium. https://youtu.be/AaZ_RSt0KP8?si=h7NKzMtJ87HRZ-bB
Cyber Chaos Crew. https://youtu.be/-KFH--_cdiI?si=S5rv8RjTtscu-S22
NBC News. https://youtu.be/lFiTjZDOekg?si=6a43qnPdveHaz6YA

Further image and video credits - https://docs.google.com/docume....nt/d/19fkGlnMj86GoIS

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Special thanks to our Patreon supporters:

Adam Foreman, Albert Wenger, Alex Porter, Alexander Tamas, Anton Ragin, Autodidactic Studios, Balkrishna Heroor, Bertrand Serlet, Blake Byers, Bruce, Dave Kircher, David Johnston, David Tseng, Evgeny Skvortsov, Garrett Mueller, Gnare, gpoly, Greg Scopel, HydrochloRick, Juan Benet, Keith England, KeyWestr, Kyi, Lee Redden, Marinus Kuivenhoven, Matthias Wrobel, Meekay, meg noah Michael Krugman, Orlando Bassotto, Paul Peijzel, Richard Sundvall, Sam Lutfi, TTST, Tj Steyn, Ubiquity Ventures, wolfee

▀▀▀
Directed by Henry van Dyck
Written by Henry van Dyck
Edited by Trenton Oliver
On-site Interviews by Jonny Hyman
Filming by Alex Gorosh
Produced by Rob Beasley Spence, Tori Brittain, Jonny Hyman, Henry van Dyck, Gabe Strong, Zoe Heron, and Derek Muller
Animated by Emma Wright and Mike Radjabov
Additional Research by Gabe Strong and Darius Garewal
Additional Editing by James Stuart
Thumbnail contributions by Ben Powell, Ren Hurley, Peter Sheppard, Gregor Čavlović and Henry van Dyck

Additional video/photos supplied by NASA JPL, Getty Images and Storyblocks
Music from Epidemic Sound

For thousands of years, mathematicians were calculating Pi the obvious but numerically inefficient way. Then Newton came along and changed the game. This video is sponsored by Brilliant. The first 314 people to sign up via https://brilliant.org/veritasium get 20% off a yearly subscription.

Happy Pi Day!

References:
Arndt, J., & Haenel, C. (2001). Pi-unleashed. Springer Science & Business Media — https://ve42.co/Arndt2001

Dunham, W. (1990). Journey through genius: The great theorems of mathematics. Wiley — https://ve42.co/Dunham1990

Borwein, J. M. (2014). The Life of π: From Archimedes to ENIAC and Beyond. In From Alexandria, Through Baghdad (pp. 531-561). Springer, Berlin, Heidelberg — https://ve42.co/Borwein2012

Special thanks to Alex Kontorovich, Professor of Mathematics at Rutgers University, and Distinguished Visiting Professor for the Public Dissemination of Mathematics National Museum of Mathematics MoMath for being part of this Pi Day video.

Special thanks to Patreon supporters: Jim Osmun, Tyson McDowell, Ludovic Robillard, jim buckmaster, fanime96, Juan Benet, Ruslan Khroma, Robert Blum, Richard Sundvall, Lee Redden, Vincent, Lyvann Ferrusca, Alfred Wallace, Arjun Chakroborty, Joar Wandborg, Clayton Greenwell, Pindex, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi, Ron Neal

Written by Derek Muller and Alex Kontorovich
Animation by Ivy Tello
Filmed by Derek Muller and Raquel Nuno
Edited by Derek Muller
Music by Jonny Hyman and Petr Lebedev

Additional Music from https://epidemicsound.com "Particle Emission", "Into the Forest", "Stavselet", "Face of the Earth", "Firefly in a Fairytale"

Thumbnail by Gianmarco Malandra and Karri Denise

Einstein was wrong about black holes, what else? Use code veritasium at the link below to get an exclusive 60% off an annual Incogni plan: https://incogni.com/veritasium

A massive thank you to Prof. Geraint F. Lewis and Prof. Juan Maldacena for their expertise and help with this video.

A huge thank you to those who helped us understand this complicated topic: Dr. Suddhasattwa Brahma, Prof. Carlo Rovelli, Dr. Hal Haggard, Prof. Martin Bojowald, Dr. Francesca Vidotto, Prof. Andrew Hamilton, and Dr. Carl-Fredrik Nyberg Brodda.

A special thanks to Alessandro Roussel from ScienceClic for his spectacular simulations and feedback on the video. Check out his channel here: https://ve42.co/ScienceClic

An excellent book on this topic and an inspiration for this video: Cox, B., & Forshaw, J. (2023). Black holes: the key to understanding the universe.

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Join us on Patreon to watch an exclusive bonus video that expands on the topic of white holes 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

▀▀▀
References:
Thorne, K. (1995). Black Holes & Time Warps: Einstein's Outrageous Legacy.
Relativity Playlist by ScienceClic - https://ve42.co/SCPlaylist
Hamilton, A. J. S. (2021). General Relativity, Black Holes, and Cosmology - https://ve42.co/Hamilton2021
Black Hole Events by PBS Space Time - https://youtu.be/vNaEBbFbvcY?l....ist=PLsPUh22kYmNBl4h
Newton’s Letters via The Newton Project - https://ve42.co/NewtonMail
Einstein, A. (1915). Die feldgleichungen der gravitation. - https://ve42.co/Einstein1915
Why Time and Space Swap by ScienceClic - https://youtu.be/GQZ3R81iyE0
Schwarzschild, K. (1916). Über das Gravitationsfeld eines Massenpunktes nach der Einsteinschen Theorie. - https://ve42.co/Schwarzschild1916
Wali, K. C. (1982). Chandrasekhar vs. Eddington—an unanticipated confrontation. - https://ve42.co/Wali1982
How to Build a Black Hole by PBS Space Time - https://www.youtube.com/watch?v=xx4562gesw0
Oppenheimer, J. R., & Volkoff, G. M. (1939). On massive neutron cores. - https://ve42.co/TOVLimit
Oppenheimer, J. R., & Snyder, H. (1939). On continued gravitational contraction. - https://ve42.co/Oppenheimer1939
Schwarzschild Geometry by Andrew Hamilton - https://ve42.co/SchwarzGeom
Why all world maps are wrong by Vox - https://www.youtube.com/watch?v=kIID5FDi2JQ
Hamilton, A. J., & Lisle, J. P. (2008). The river model of black holes. - https://ve42.co/HamiltonLisle2008
Mapping The Multiverse by PBS Space Time - https://www.youtube.com/watch?v=4v9A9hQUcBQ
Rotating black hole via Wikipedia - https://ve42.co/WikiRBH
Wormhole Travel by PBS Space Time - https://www.youtube.com/watch?v=ldVDM-v5uz0
Morris, M. S., & Thorne, K. S. (1988). Wormholes in spacetime and their use for interstellar travel. - https://ve42.co/MorrisThorne1988

Images & Video:
D3 Geo Projection Library by Mike Bostock https://ve42.co/d3geo
Interrupted Maps by Jason Davies https://ve42.co/DaviesMaps
Kazmierczak, J. et al. (2021). NASA’s NICER Tests Matter’s Limits. - https://ve42.co/NasaNICER
Bridgman, T. et al. (2024). M5.1 flare 'Double Whammy', at Active Regions 13559 and 13561. NASA SVS. - https://ve42.co/NasaFlare
Schnittman, J. et al. (2019). Black Hole Accretion Disk Visualization. - https://ve42.co/NasaAccrDisk
Wiessinger, S. et al. (2020). A Decade of Sun. NASA SVS. - https://ve42.co/NasaSunDecade
Skelly, C. et al. (2017). What is a Neutron Star? NASA SVS. - https://ve42.co/NasaNeutron
What would we see if we fell into a black hole by ScienceClic - https://youtu.be/4rTv9wvvat8
Earth texture - https://ve42.co/NASAEarth
First image of Sgr A* - https://ve42.co/EHT1
Image of M87 - https://ve42.co/EHT2
Polarized light image of Sgr A* - https://ve42.co/EHT3

▀▀▀
Directed by Casper Mebius
Written by Casper Mebius, Derek Muller and Will Wood
Edited by Trenton Oliver
Animated by Fabio Albertelli, Ivy Tello, Mike Radjabov, David Szakaly, Jonny Hyman, and Alessandro Roussel
Illustrated by Jakub Misiek
Filmed by Derek Muller
Additional research by Gregor Čavlović
Produced by Casper Mebius, Derek Muller, Will Wood, Giovanna Utichi, Rob Beasley Spence, Gregor Čavlović, and Emily Taylor

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

Apollo astronauts trained in nuclear bomb craters at the Nevada National Security Site. But why?Thanks Audible! Start listening with a 30-day trial and your first audiobook plus two Audible Originals free when you go to http://audible.com/veritasium or text veritasium to 500500

I found this story fascinating because in a way a nuclear bomb crater is more like a meteorite impact site than an impact site itself. Consider: Barringer Crater was claimed to be a meteorite impact site but geologists dismissed it as a volcanic formation. It was only after studying nuclear bomb craters and the minerals found there that geologists concluded the energy and pressures that created Barringer Crater were too high to be from volcanic activity and therefore must have formed from a meteorite impact.

Special Thanks to:
Nevada National Security Site
The National Atomic Testing Museum
Jonny Hyman and Verse: https://youtu.be/7bUUGzi-AAY
Active Galactic for footage of craters in Arizona: https://youtu.be/yhoooBpndog

Special thanks to Patreon supporters:
a human, Alfred Wallace, Arjun Chakroborty, Brent Stewart, Bryan Baker, Chris Vargas, Chuck Lauer Vose, Clip Tree, Coale Shifflett, Colin Bellmore, DALE HORNE, Daniel Milum, Donal Botkin, Eric Velazquez, Illya Nayshevsky, James Knight, James Wong, Jasper Xin, Joar Wandborg, Johnny, June Kang, Kevin Beavers, kkm, Leah Howard, Listen Money Matters, Lyvann Ferrusca, Manuel Zürcher, Mathias Göransson, Michael Bradley Wirz, Michael Krugman, Mohammed Al Sahaf, OddJosh, Philipp Volgger, Pindex, Roberto Rezende, Robin DeBank, Ron Neal, Sam Lutfi, Stan Presolski, Tige Thorman, Warrior8252

Filmed by Raquel Nuno
Story and Editing by Derek Muller and Jonny Hyman
Music and Animation by Jonny Hyman
Produced by Casey Rentz

Aerogels are the world's lightest (least dense) solids. They are also excellent thermal insulators and have been used in numerous Mars missions and the Stardust comet particle-return mission. The focus of this video is silica aerogels, though graphene aerogels are now technically the lightest.

At one point Dr. Steven Jones literally held the Guinness World Record for making the lightest aerogel and therefore lightest solid. If you're interested in learning more about aerogels, let me know in the comments as there is a potential trilogy in the works...

Huge thanks to Dr. Stephen Steiner and the crew at Aerogel Technologies. To find out more or buy your own aerogel sample, check out: http://www.aerogeltechnologies.com/

Thanks to Dr. Steven Jones and Dr. Mihail Petkov at NASA's Jet Propulsion Laboratory

And thanks to FLIR for loaning us the awesome high definition thermal camera. The footage is amazing! https://www.flir.com

Special thanks to Patreon supporters:
Donal Botkin, Michael Krugman, Ron Neal, Stan Presolski, Terrance Shepherd, Penward Rhyme and everyone who provided feedback on an early draft of this video.

Filming by Raquel Nuno
Animations by Maria Raykova
Drawings by Mariel Solsberg

Music From http://epidemicsound.com "Seaweed" "Swagger Stagger"

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. 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-1160428

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/LeastActionRefs

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 Strong, Gregor Čavlović, and Geeta Thakur
Produced by Casper Mebius, Derek Muller, Rob Beasley Spence, Gabe Strong, 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