Stephen Hawking thought an asteroid impact posed the greatest threat to life on Earth. Thanks to Kiwico for sponsoring this video. For 50% off your first month of any crate, go to https://kiwico.com/veritasium50
For other potential world ending catastrophes, check out Domain of Science: https://ve42.co/DoS

Special thanks to:
Prof. Dave Jewitt from UCLA Earth, Planetary, and Space Sciences
Prof. Mark Boslough from Sandia National Labs
Scott Manley: https://www.youtube.com/user/szyzyg
Ryan Wyatt at Morrison Planetarium
Prof. Amy Mainzer
Alexandr Ivanov for the opening shot of Chelyabinsk Meteor

Maps of Asteroid Impacts —https://ve42.co/Map

Time passing animation from Universe Sandbox - http://universesandbox.com/

Opposition Effect — https://ve42.co/Belskaya2000
Belskaya, I. N., & Shevchenko, V. G. (2000). Opposition effect of asteroids. Icarus, 147(1), 94-105.

Potentially Hazardous Asteroids — https://ve42.co/Perna2013
Perna, D., Barucci, M. A., & Fulchignoni, M. (2013). The near-Earth objects and their potential threat to our planet. The Astronomy and Astrophysics Review, 21(1), 65.

Survey of Potentially Hazardous Asteroids — https://ve42.co/NEOSurvey

Population Vulnerability — https://ve42.co/Rumpf2017
Rumpf, C. M., Lewis, H. G., & Atkinson, P. M. (2017). Population vulnerability models for asteroid impact risk assessment. Meteoritics & Planetary Science, 52(6), 1082-1102.

Size distribution of NEOs — https://ve42.co/Trilling17
Trilling, D. E., Valdes, F., Allen, L., James, D., Fuentes, C., Herrera, D., ... & Rajagopal, J. (2017). The size distribution of near-earth objects larger than 10 m. The Astronomical Journal, 154(4), 170.

2020 NEOWISE Data Release — https://ve42.co/NEOWISE

National Research Council Report— https://ve42.co/Defending
Board, S. S., & National Research Council. (2010). Defending planet earth: Near-Earth-Object surveys and hazard mitigation strategies. National Academies Press.

Tug Boat — https://ve42.co/Schweickart03
Schweickart, R. L., Lu, E. T., Hut, P., & Chapman, C. R. (2003). The asteroid tugboat. Scientific American, 289(5), 54-61.

Gravity Tractor 1 — https://ve42.co/Lu05
Lu, E. T., & Love, S. G. (2005). Gravitational tractor for towing asteroids. Nature, 438(7065), 177-178.

Laser Ablation — https://ve42.co/Thiry14
Thiry, N., & Vasile, M. (2014). Recent advances in laser ablation modelling for asteroid deflection methods. SPIE Optical Engineering+ Applications, 922608-922608.

Yarakovsky Effect — https://ve42.co/Yara

DART Mission — https://ve42.co/DART

Nuclear 1 — https://ve42.co/Ahrens92
Ahrens, T. J., & Harris, A. W. (1992). Deflection and fragmentation of near-Earth asteroids. Nature, 360(6403), 429-433.

Nuclear 2 — https://ve42.co/Bradley10
Bradley, P. A., Plesko, C. S., Clement, R. R., Conlon, L. M., Weaver, R. P., Guzik, J. A., ... & Huebner, W. F. (2010, January). Challenges of deflecting an asteroid or comet nucleus with a nuclear burst. In AIP Conference Proceedings (Vol. 1208, No. 1, pp. 430-437). American Institute of Physics.

Researched and Written by Petr Lebedev, Jonny Hyman and Derek Muller
3D animations, VFX, SFX, Audio Mixing by Jonny Hyman
2D animation by Ivy Tello
Intro animation by Nicolas Pratt
With Filming by Raquel Nuno

Music from https://epidemicsound.com "Stellar Dance" "Orbit" "That Notebook" "What We Discovered" "Out of Poppies" "Handwriting"
Images and video supplied by Getty Images

People claim that 70-80% of household dust is dead skin, but is it true?
Thanks to Google for sponsoring this video! Learn more about Search here: https://www.google.com/search/howsearchworks/

Special thanks to J.M.E.H van Bronswijk, author of 'House Dust Biology'. We exchanged emails to make sure I got my facts straight for this video. Below is an excerpt from her email to me, responding to my claims that start with a dash:

- Around half of airborne dust particles under 100um are skin scales
This is true for climates, regions and seasons where people live mostly indoors.
The 1 to 2 g of skin scales shed each 24 hours will end up in places where people are present (and rub their skin or have textile moving over the skin).
You can also look at it from a different angle: What else has the same size and could contribute? That will usually be pollen from outdoor sources, also depending on season, region and climate, as well as the ventilation regime of the building.
However, taken as the median value over a whole year, I consider your statement correct for regions with a temperate climate.

- 53% of dust particles vacuumed from a mattress were found to be skin scales
It depends a little on the type of mattress. For polyether mattresses the amount may even be larger.
For mattresses made of natural material it could be less since the mattress-material will also give off small particles.

- larger particles consist mostly of fibers, eg. cotton, paper, wool, synthetics
That's true .. including bread crumbs ..... 🙂

- skin scales seem to form a larger fraction of dust where we spend more time, e.g. in or near bed.
..... and on the couch used to view television or be active in gaming.
It has to do with the constant production of skin scales over the 24 hours.

- skin scales form a smaller fraction of dust if there are significant other sources, e.g. carpeting, dirt from outside etc.
Yes, everyting you walk on with your shoes or that recieves dirt from the outside with other means, will have a lessr percentage of human skin scales.
However, do not forget the skin scales of pets that will also be an active allergen for many people, and a food source for house dust mites.

Information on dust particle size ©ISO. This material is adapted from ISO 7708:1995, with permission of the American National Standards Institute (ANSI) on behalf of the International Organization for Standardization. All rights reserved.

Research and Writing by AJ Fillo and Derek Muller
Editing, Audio Mix & Master, and Computer animations by Jonny Hyman
Dust and character animation by Ivy Tello
Filming by Raquel Nuno
Thumbnail by Fictionalhead https://www.youtube.com/fictionalhead

Intro Music composed by Jonny Hyman
Additional Music from Epidemic Sound: Colored Spirals, Observations

This is the biggest, brightest, hottest video there is about the science of fireworks. This video is brought to you by Kiwico – go to https://kiwico.com/veritasium for your first month free!

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

Check out Gene’s channel here -- @PotatoJet

Massive thanks to Mike Tockstein from Pyrotechnic Innovations @PyroInnovations
and Will Scott from Las Vegas Display Fireworks Inc, for all your pyro knowledge and keeping us safe.

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Massive thanks to Gene Nagata from PotatoJet for filming this episode – check out his wonderful channel for more videos about cameras and FPV drones.

Thanks to Brandon Williams for helping with the chemistry and sourcing of materials.

Thanks to Matthew Tosh for the help with the chemistry conversation about fireworks.

Thanks to Simon Werrett for the help with the history of fireworks.

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Werrett, S. (2010). Fireworks: pyrotechnic arts and sciences in European history. University of Chicago Press

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Special thanks to our Patreon supporters:
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Written by Derek Muller
Edited by Trenton Oliver
Animated by Ivy Tello and Fabio Albertelli
Filmed by Derek Muller, Hunter Peterson, Gene Nagata, Raquel Nuno
Production by Hunter Peterson and Stephanie Castillo
Additional video/photos supplied by Mike Tockstein/Pyrotechnic Innovations
Music from Epidemic Sound & Jonny Hyman
Produced by Derek Muller, Petr Lebedev, Emily Zhang, & Casper Mebius

Aerogel has extraordinary properties but it can be tough to work with. This video looks at modifying aerogels to take advantage of their unique characteristics.
Subscribe to Veritasium: https://ve42.co/sub

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

Aerogel’s extraordinary properties are due in large part to its structure. Aerogel is a solid but on the nanoscale it has a mesh or sponge-like structure. The struts of this structure are nanoscale, as are the pores at around 20nm across. This makes silica aerogel incredibly light (it was once the lightest solid but has now been superseded by graphene aerogel), transparent and adsorbent.

An ice-cube sized piece of aerogel has an internal surface area roughly equal to half a football field. Aerogel is used in high end museum cases to regulate humidity. Plus it helps maintain the vacuum on the Mars Insight seismometers - it adsorbs moisture and other outgassed volatiles that come from the spacecraft itself. Proposed uses include as a physical insecticide by ‘drying out insects’ reducing the need for chemical and toxic pesticides.

Special thanks to all my Patreon supporters especially those who contributed feedback to an earlier draft of this video:
a human, Albert Jachowicz-Brzeziński, Alfred Wallace, Arjun Chakroborty, Brent Stewart, Chris Vargas, Chuck Lauer Vose, Clip Tree, Coale Shifflett, Colin Bellmore, DALE HORNE, Eric Velazquez, Fedor Indutny, Fran Rodriguez, James Wong, Jasper Xin, Joar Wandborg, Johnny, Jorge Angel Sandoval, June Kang, Kevin Beavers, Kishore Tipirneni, Levan Ferr, Listen Money Matters, Manuel Zürcher, Mark Bevilacqua, Mathias Göransson, Michael Bradley Wirz, Michael Krugman, Mohammed Al Sahaf, Nicholas Hastings, OddJosh, Patrick Čalija, Peter Tajti, Philipp Volgger, Roberto Rezende, Robin DeBank, Ron Neal, Stan Presolski, Swante Scholz, Tiago Bruno, Tige Thorman, Warrior8252

Filmed by Paul Gramaglia

Thumbnail by Ignat Berbeci

Animations by Catherine Chooljian

Music from https://epidemicsound.com “Tonic Zone” “Betelgeuse” “Insidious Mice” “Seaweed” “It’s not that serious” “Platin00m - Sum It”

This is an educational, scientific video.

The world's strongest magnet is a million times stronger than Earth's magnetic field. Learn more about sustainability and Google’s efforts at sustainability.google. Part of this video was sponsored by Google.

Trends insights for the past year are based on Google Trends data from 2/10/2022 - 2/10/2023, U.S.

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Thanks to the entire NHMFL team - especially Tim, Stephen, Caroline, Kristin, Sam, Lance, and everyone who helped with the demos - for the great visit.
The NHMFL is funded by the National Science Foundation and the State of Florida.

Special thanks to Henry from Minutephysics for lending his magnet animations from our magnet collaboration: https://youtu.be/hFAOXdXZ5TM

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References:
Liu, Y., Zhu, D. M., Strayer, D. M., & Israelsson, U. E. (2010). Magnetic levitation of large water droplets and mice. Advances in Space Research, 45(1), 208-213.

Simon, M. D., & Geim, A. K. (2000). Diamagnetic levitation: Flying frogs and floating magnets. Journal of applied physics, 87(9), 6200-6204.

Berry, M. V., & Geim, A. K. (1997). Of flying frogs and levitrons. European Journal of Physics, 18(4), 307.

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Special thanks to our Patreon supporters:
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Written by Derek Muller
Edited and Motion Graphics by Trenton Oliver
Coordinated by Emily Zhang and Derek Muller
Filmed by Derek Muller, Trenton Oliver, Raquel Nuno 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

Can we really touch things? Well if by touch we mean exchange a force-carrying particle with, then yes. The photon is the force-carrier of the electromagnetic interaction. But if the photon is also a particle of light then why aren't magnets glowing? Because the photons are virtual particles, which means they can't be directly detected (without changing the outcome we are trying to measure.
Supported by Audible: http://bit.ly/ZJ5Q6z
Who would win in a chin-up competition between me and MinutePhysics? What is going to be the most exciting area of scientific discovery in the next few decades? Where can you get a Veritasium t-shirt? http://dft.ba/-vetshirt
Huge thanks to Brady, CGP Grey, and Henry for their cameos.

Thank you to PhET for the Bohr model simulation: http://phet.colorado.edu/

Spinning objects have strange instabilities known as The Dzhanibekov Effect or Tennis Racket Theorem - this video offers an intuitive explanation.
Part of this video was sponsored by LastPass, click here to find out more: https://ve42.co/LP

References:
Prof. Terry Tao's Math Overflow Explanation: https://ve42.co/Tao

The Twisting Tennis Racket
Ashbaugh, M.S., Chicone, C.C. & Cushman, R.H. J Dyn Diff Equat (1991) 3: 67. https://doi.org/10.1007/BF01049489

Janibekov’s effect and the laws of mechanics
Petrov, A.G. & Volodin, S.E. Dokl. Phys. (2013) 58: 349. https://doi.org/10.1134/S1028335813080041

Tumbling Asteroids
Prave et al. https://doi.org/10.1016/j.icarus.2004.07.021

The Exact Computation of the Free Rigid Body Motion and Its Use in Splitting Methods
SIAM J. Sci. Comput., 30(4), 2084–2112
E. Celledoni, F. Fassò, N. Säfström, and A. Zanna
https://doi.org/10.1137/070704393

Animations by Ivy Tello and Isaac Frame

Special thanks to people who discussed this video with me:
Astronaut Don Pettit
Henry Reich of MinutePhysics
Grant Sanderson of 3blue1brown
Vert Dider (Russian YouTube channel)

Below is a further discussion by Henry Reich that I think helps summarize why axes 1 and 3 are generally stable while axis 2 is not:

In general, you might imagine that because the object can rotate in a bunch of different directions, the components of energy and momentum could be free to change while keeping the total momentum constant.

However, in the case of axis 1, the kinetic energy is the highest possible for a given angular momentum, and in the case of axis 3, the kinetic energy is the lowest possible for a given angular momentum (which can be easily shown from conservation of energy and momentum equations, and is also fairly intuitive from the fact that kinetic energy is proportional to velocity squared, while momentum is proportional to velocity - so in the case of axis 1, the smaller masses will have to be spinning faster for a given momentum, and will thus have more energy, and vice versa for axis 3 where all the masses are spinning: the energy will be lowest). In fact, this is a strict inequality - if the energy is highest possible, there are no other possible combinations of momenta other than L2=L3=0, and vice versa for if the energy is the lowest possible.

Because of this, in the case of axis 1 the energy is so high that there simply aren't any other possible combinations of angular momentum components L1, L2 and L3 - the object would have to lose energy in order to spin differently. And in the case of axis 3, the energy is so low that there likewise is no way for the object to be rotating other than purely around axis 3 - it would have to gain energy. However, there's no such constraint for axis 2, since the energy is somewhere in between the min and max possible. This, together with the centrifugal effects, means that the components of momentum DO change.

Many technologies have promised to revolutionize education, but so far none has. With that in mind, what could revolutionize education?
These ideas have been percolating since I wrote my PhD in physics education: https://ve42.co/phd
I have also discussed this topic with CGP Grey, whose view of the future of education differs significantly from mine: https://www.youtube.com/watch?v=7vsCAM17O-M

I think it is instructive that each new technology has appeared to be so transformative. You can imagine, for example, that motion pictures must have seemed like a revolutionary learning technology. After all they did revolutionize entertainment, yet failed to make significant inroads into the classroom. TV and video seem like a cheaper, scaled back film, but they too failed to live up to expectations. Now there is a glut of information and video on the internet so should we expect it to revolutionize education?

My view is that it won't, for two reasons: 1. Technology is not inherently superior, animations over static graphics, videoed presentations over live lectures etc. and 2. Learning is inherently a social activity, motivated and encouraged by interactions with others.

Filmed and edited by Pierce Cook

Supported by Screen Australia's Skip Ahead program.

Music By Kevin MacLeod, www.incompetech.com "The Builder" and by Amarante Music: http://www.amarantemusic.com

How Schlieren imaging works in color, black and white and slow-mo.
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Filming by Raquel Nuno
Sound Effects by A Shell in the Pit

Acrylic Ball: http://bit.ly/BBBacrylic
Ping-Pong Ball: http://bit.ly/BBBpingpong
Balanced: http://bit.ly/BBBbalanced

This problem has made the rounds on the internet but I felt it deserved a treatment like this.

Special thanks to Gary and the Department of Earth, Planetary and Space Sciences at UCLA, to the students for participating, to Ivy for helping me coordinate everything and to Raquel for filming.

Music by Kevin MacLeod, http://incompetech.com "Monkeys, Spinning Monkeys"

What is the specious present? And how do our brains perceive time?
Get a 30-day free trial on Audible: http://bit.ly/AudibleVe
More info about this topic: http://wke.lt/w/s/z8TeR

Discover strange new universes that turn up at the core of Einstein’s General Relativity. 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.

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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. Alex Kontorovich for all his help with this video.

A huge thank you to Prof. Geraint Lewis and Dr. Ashmeet Singh for helping us understand the applications of Non-Euclidean geometry in astronomy/cosmology.

Lastly, a big thank you to Dr. Henry Segerman and Dr. Rémi Coulon for helping us visualize what it’s like to be inside hyperbolic space and helping us understand hyperbolic geometry.

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Images:
Euclid via Science Museum Group - https://ve42.co/Euclid

Geodesy survey via ams - https://ve42.co/Geodesy

John Wheeler via NAS Online - https://ve42.co/Wheeler

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References:
Dunham, W. (1991). Journey through Genius: Great Theorems of Mathematics. John Wiley & Sons.

Bonola, R. (1955). Non-Euclidean geometry: A critical and historical study of its development. Courier Corporation.

Library of Congress. (n.d.). The Library of Congress. - https://ve42.co/LibofCongress

Euclid’s Elements, Wikipedia - https://ve42.co/Elements

The History of Non-Euclidean Geometry, Extra History via YouTube - https://ve42.co/ExtraHistory

We (could) live on a 4D Pringle - Physics for the Birds via YouTube - https://ve42.co/4DPringle

Parallel Postulate, Wikipedia - https://ve42.co/Parallel

Prékopa, A., & Molnár, E. (Eds.). (2006). Non-euclidean geometries: János Bolyai memorial volume (Vol. 581). Springer Science & Business Media.

St Andrews, University of. (n.d.). Bolyai. MacTutor History of Mathematics. - https://ve42.co/Bolyai

Bolyai, J. (1896). The Science Absolute of Space.. (Vol. 3). The Neomon.

Gauss, Wikipedia - https://ve42.co/Gauss

Singh, U. (2022). Gauss-Bolyai-Lobachevsky: The dawn of non-euclidean geometry. Medium. - https://ve42.co/CPNonEuclidean

Landvermessung, D. Z. (1929). Abhandlungen ueber Gauss' wissenschaftliche Taetigkeit auf den Gebieten der Geodaesie, Physik und Astronomie Bd. 11, Abt. - https://ve42.co/Landvermessung

Nikolai Lobachevsky, Wikipedia - https://ve42.co/Lobachevsky

Lobachevskiĭ, N. I. (1891). Geometrical researches on the theory of parallels. University of Texas.

A Problem with the Parallel Postulate, Numberphile via YouTube - https://ve42.co/NumberphileParallel

Riemann, B. (2016). On the hypotheses which lie at the bases of geometry. Birkhäuser. - https://ve42.co/Riemann

Einstein, A. (1905). On the electrodynamics of moving bodies. Annalen der physik, 17(10), 891-921. - https://ve42.co/Einstein1905

ESA/Hubble. (n.d.). Hubblecast 90: The final frontier of the Frontier Fields. ESA/Hubble. - https://ve42.co/Einstein1905

Agazie, G., et al. (2023). The NANOGrav 15 yr data set: Constraints on supermassive black hole binaries from the gravitational-wave background. - https://ve42.co/NANOGrav

Secrets of the Cosmic Microwave Background, PBS Spacetime via YouTube - https://ve42.co/PBSCMB

Wood, C. (2020). How Ancient Light Reveals the Universe's Contents. Quanta Magazine. - https://ve42.co/AncientLight

Collaboration (2014). Planck 2013 results. XVI. Cosmological parameters. A&A, 571, A16. - https://ve42.co/Planck2013

WMAP Science Team, NASA. (2014). Matter in the Universe. WMAP, NASA. - https://ve42.co/WMAP2014

What Is The Shape of Space, minutephysics via YouTube - https://ve42.co/SpaceShape

Shape of the universe, Wikipedia - https://ve42.co/UniverseShape

Crocheting Hyperbolic Planes: Daina Taimina by Ted, via YouTube - https://ve42.co/Hyperbolic

Hyperbolic Crochet model - https://ve42.co/Crochet

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Directed by Casper Mebius
Written by Casper Mebius, Petr Lebedev, Emily Zhang, Derek Muller, and Alex Kontorovich
Edited by Jack Saxon
Animated by Fabio Albertelli, Ivy Tello, and Mike Radjabov
Illustrations by Jakub Misiek and Celia Bode
Filmed by Derek Muller
Produced by Casper Mebius, Derek Muller, and Han Evans

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’s WMAP science teams, ESO, and ESA/Hubble.
Music from Epidemic Sound
Thumbnail by Ren Hurley

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A huge thank you to Dr Asaf Karagila, Prof. Alex Kontorovich, Prof. Joel David Hamkins, Prof. Andrew Marks, Prof. Gabriel Goldberg and Prof. Elliot Glazer for their invaluable expertise and contributions to this video.

Head over and sign up to our Patreon for some exclusive behind the scenes footage, showing how the animations and illustrations for this video were made - https://www.patreon.com/posts/patreon-behind-126443880?utm_medium=clipboard_copy&utm_source=copyLink&utm_campaign=postshare_creator&utm_content=join_link

▀▀▀
0:00 What comes after one?
2:42 Some infinities are bigger than others
6:17 The Well Ordering Principle
10:32 Zermelo And The Axiom Of Choice
17:22 Why is the axiom of choice controversial?
23:16 The Banach–Tarski Paradox
27:53 Obviously True, Obviously False
29:58 Your Proof Your Choice

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References:

Up and Atom - https://www.youtube.com/watch?v=X56zst79Xjg
Minutephysics - https://www.youtube.com/watch?v=A-QoutHCu4o
PBS Infinite Series - https://www.youtube.com/watch?v=hcRZadc5KpI&t=125s
Vsauce - https://www.youtube.com/watch?v=s86-Z-CbaHA&t=474s
Ernst Zermelo via Wikipedia - https://ve42.co/zermeloBio
Axiom of choice via Wikipedia - https://ve42.co/choiceAxiom
Georg Cantor via Wikipedia - https://ve42.co/cantorMath
Gregory H. Moore (2013). Consequences of the Axiom of Choice. Dover Publications - https://ve42.co/choiceBook
Georg Cantor (1874). On a property of the class of all real algebraic numbers. Journal für die Reine und Angewandte Mathematik - https://ve42.co/MeyerCantor1874
Heinz-Dieter Ebbinghaus (Dec 2012). Zermelo and the Heidelberg Congress 1904. Historia Mathematica - https://ve42.co/SciDirect1904
Herbert B. Enderton (1977). Elements of Set Theory. - https://ve42.co/SciDirectGCH

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

Images & Video:

Foundations of a general theory of sets by Georg Cantor via ViaLibri - https://ve42.co/grundlagen
Alfred Tarski by George Bergman via Wikimedia Commons - https://ve42.co/tarski
Alfred Tarski Offprint Group by Alfred Tarski via Bonhams - https://ve42.co/tarskipaper
La mission strasbourgeoise de Maurice Fréchet by Laurent Mazliak via Images des mathematiques - https://ve42.co/frechet
Kurt Gödel by Alfred Eisenstaedt via New Yorker - https://ve42.co/godel
Leopold Kronecker by Granger via Fine Art America - https://ve42.co/kronecker
Lashi Bandara (2006). Zermelo-Frankel Set Theory and Well Orderings. ResearchGate - https://ve42.co/zermelofrankel
Heidelberg, Germany 1936 by Wagner & Debes via Ward Maps - https://ve42.co/heidelberg
Pythagoras by J. Augustus Knapp via the marginalian - https://ve42.co/pythag
Paul Cohen by C. J. Mozzochi via C. J. Mozzochi - https://ve42.co/paulcohen
Instituto de Matemática Pura e Aplicada. Lecture 01: Introduction: a non-measurable set via Youtube - https://www.youtube.com/watch?v=llnNaRzuvd4&t=834s
Simons Foundation. Fields Medal: James Maynard. Youtube https://www.youtube.com/watch?v=un-z8kgOrV0&t=8s

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Directed by Kaela Albert
Written by Kaela Albert and Emily Zhang
Edited by Jack Saxon and Luke Molloy
Assistant Edited by James Stuart
Animated by Fabio Albertelli, Andrew Neet, Alex Zepharin, Mike Radjabov, Emma Wright and Ivy Tello
Illustrations by Jakub Misiek, Maria Gusakovich, Cainejan Esperanza, Tommy A. Steven and Emma Wright
Additional research by Emilia Gyles, Gabe Bean, Geeta Thakur and Vincent Cheng
Produced by Kaela Albert, Casper Mebius, Derek Muller, Emily Zhang, Zoe Heron, Rob Beasley Spence, and Tori Brittain
Additional Editing by Luke Molloy and James Stuart

Thumbnail contributions by Ben Powell, Peter Sheppard and Ren Hurley

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

Electric cars are now ready to take over thanks to advances in battery technology and their inherent benefits: torque, handling, maintenance. This video was sponsored by BMW: https://www.bmwusa.com/

Full disclosure: I drive an #electric #car. I think electric cars are the future, not mainly because they're better for the environment (which they are if you drive the car for any reasonable length of time) but because they are just better cars. The have better torque and acceleration, better handling, they're more efficient, quieter, they don't smell, they're cheaper to run and best of all you never have to visit a gas station - this appeals to me. I never have to worry about being low on gas because every morning my car is charged and ready to go - just like my phone and laptop. And if you're worried about range, don't. Almost all trips can already be done in an electric car with modest battery pack. And fast chargers along the way make it possible to do longer road trips if necessary. You have to make rest stops anyway, just time them with the charging. And consider that battery tech is getting dramatically cheaper, smaller, lighter. All these reasons are why I see the #future of cars as electric.

Writing & Research
Derek Muller
Jonny Hyman
Matthew Shribman https://ve42.co/sciencebath

Editing, Animation, Audio, & Music:
Jonny Hyman

Camerawork:
Raquel Nuno
Jonny Hyman

1890s Music "National fantasie" by William Paris Chambers, archived in Library of Congress
#BMWUSA #NEXTGen #BMWPartner #ad

A song about Gravity set to the tune of John Mayer's Gravity.

Gravity is working with me
And Gravity, keeps me on the ground

All mass attracts all other mass
a force proportional to mass one and two
and inversely to the distance between them squared

Oh, gravity is working with me
and gravity, makes apples fall to ground

Oh twice the mass has twice the pull
but the force on each is still equal
It keeps the moon and the satellites
going round

Oh twice the mass has twice the pull
but the force on each is still equal
It keeps the moon and the satellites
going round

Oh gravity, the force that makes weight on me
Woah, gravity, now general relativity (how can that be?)

The force between us all is
The force between us all is
The force between us all is
Gravity between us all is
Gravity between us all is
Gravity between gravity between us all is

Microwave grape plasma: http://www.youtube.com/watch?v=RwTjsRt0Fzo
Northern Lights: http://www.youtube.com/watch?v=knwiWm4DpvQ
Nanodiamonds in candle flames: http://www.youtube.com/watch?v=KzOkuGQC3Rw
Relight Candle Trick: http://www.youtube.com/watch?v=1tXPVTIisl0

Is a flame really a plasma? Well it depends on your definition of plasma, but there are certainly ions in a flame, formed as molecules collide with each other at high speed, sometimes knocking electrons off of their atoms.

Special thanks to the Palais de la Decouverte for helping me perform this experiment. Using tens of thousands of volts on two metal plates, we created a strong electric field around the plasma. This pulled positive ions in one direction and negative ions in the other direction elongating the flame horizontally and causing it to flicker like a "papillon" (butterfly). Then we showed that much longer sparks can be made through the flame than through air since the ions increase the conductivity.

How much information is there in Spanish vs English, you vs the world? Check out Audible: http://bit.ly/AudibleVe
Huge thanks to all the amazing people who made this possible:
Christina Ochoa - Spanish https://twitter.com/christina_ochoa
Vanessa Hill - Filming https://www.youtube.com/braincraftvideo
Henry Reich - Filming, cameo http://youtube.com/minutephysics
Cara Santa Maria - Set design http://carasantamaria.com
Michael Stevens - cameo http://youtube.com/vsauce
Crystal Dilworth - consultation https://twitter.com/PolycrystalhD

Thanks also to MinutePhysics for wardrobe and lending the use of the amazing "Things to do when it's really cold outside" video: https://www.youtube.com/watch?v=j3Gs6tyiNX4

More on this theme to come in the main collaboration with Vsauce.

My hypothesis is that the algorithm, rather than viewer preference, drives views on the site. As the algorithm shifts, various YouTubers experience burnout (as what used to work no longer works) and right now click-through rate is the key metric. So clickable titles and thumbnails are the only way to get a lot of impressions and hence views - they are the only way to go viral. This leads me to wonder which audiences will become most prevalent on the site and if there will even be a place for educational content. In the long-term, hopefully YouTube is able to measure satisfaction through surveys and other metrics to ensure an optimal experience for everyone on the site.

Flipchart artwork by Maria Raykova
Filmed by Raquel Nuno
Thumbnail by Ignat Berbeci

A story is worth a thousand data points.
My second channel: http://bit.ly/2veritasium
More info on this topic: http://wke.lt/w/s/TzNC0

Check out 2Veritasium! https://ve42.co/2Ve
MinutePhysics has a great video on Milkman, vomiting levitator: http://dft.ba/-vomphysics
Jetpacking was awesome fun! Despite the fat lip I had a great time. I think knowing a bit about physics actually helps fly the jetpack. It works on the same principle as a rocket (Newton's 3rd law) but unlike the shuttle, you don't carry your own propellant with you. Instead, water is pumped out of the lake by the jetski at up to 60 litres a second. It is then fired out of the nozzles at around 15 m/s creating 1800 N of force, the equivalent of about 150 fire extinguishers. On me this can produce acceleration of about 1.5g's.

Music by Kevin McLeod (http://incompetech.com) Silly Fun, Also Sprach Zarathustra
Supported by Science Alert: http://on.fb.me/14ehuxA
Slow motion filming by Questacon: http://bit.ly/ZoWFGR

The Perseverance Rover and helicopter Ingenuity have landed safely on Mars. A few years back I got to visit NASA JPL to interview the scientists to find out their goals for the mission. I made this clip as a correspondent for Bill Nye Saves the World on Netflix.

Touring the Jet Propulsion Lab (JPL) in Pasadena was an awesome experience. I didn't think we were going to get into the control room but we got lucky. Some of the greatest moments in the history of space exploration have taken place there. They have a giant vacuum chamber where they can take the rover down to the atmospheric pressure on Mars (roughly .01x Earth's atmosphere) and test all of the devices to make sure there are no electrical discharges due to the reduced pressure. I also enjoyed seeing how the rocks will be cored and stored in tubes and deposited on the Martian surface awaiting pickup by the following mission.

Images courtesy of NASA.

Filmed by Raquel Nuno from 3:30 onwards.

Music: http://epidemicsound.com "Serene Story 2"

Why we can't seem to agree on what's true when it's easier than ever to check.
Videos like this are usually on 2Veritasium: http://bit.ly/2Veritasium
Support Veritasium on Patreon: http://bit.ly/VePatreon

This video was filmed at a meetup in Stockholm, Sweden on Dec. 9, 2016. Huge thanks to everyone who attended - I had a great time. Sorry to those of you I missed, especially Lund and Gothenburg.

Thanks to Patreon supporters (but this is a non-paid post):
Meshal Alshammari, Nathan Hansen, Bryan Baker, Donal Botkin, Tony Fadell, Saeed Alghamdi, Ron Neal

How the Black-Scholes/Merton equation made trillions of dollars. Go to https://www.eightsleep.com/veritasium and use the code Veritasium for $200 off your Pod Cover.

Special thanks to our Patreon supporters! Join this list 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 huge thank you to Prof. Andrew Lo (MIT) for speaking with us and helping with the script.

We would also like to thank the following:
Prof. Amanda Turner (University of Leeds)
Owen Maher (Electrify Video Partners)

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References:

The Man Who Solved the Market: How Jim Simons launched the quant revolution, Gregory Zuckerman. Penguin Publishing Group. - https://ve42.co/GZuckerman

The Physics of Finance: Predicting the Unpredictable: Can Science Beat the Market? James Owen Weatherall. Short Books. - https://ve42.co/FinancePhysics

The Statistical Mechanics of Financial Markets, J.Voigt. Springer. - https://ve42.co/Springer

Black, F., & Scholes, M. (1973). The pricing of options and corporate liabilities. Journal of political economy, 81(3), 637-654. - https://ve42.co/BlackScholes

Cornell, B. (2020). Medallion fund: The ultimate counterexample?. The Journal of Portfolio Management, 46(4), 156-159. - https://ve42.co/Medallion

Images & Video:
Ed Thorp on The Tim Ferris Show - https://www.youtube.com/watch?v=CNvz91Jyzbg
Jim Simons on TED - https://www.youtube.com/watch?v=U5kIdtMJGc8
Jim Simons on Numberphile - https://www.youtube.com/watch?v=QNznD9hMEh0

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Special thanks to our Patreon supporters:
Adam Foreman, Anton Ragin, Balkrishna Heroor, Bill Linder, Blake Byers, Burt Humburg, Chris Harper, Dave Kircher, David Johnston, Diffbot, Evgeny Skvortsov, Garrett Mueller, Gnare, I.H., 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 Will Wood and Derek Muller
Written by Will Wood, Emily Zhang, Petr Lebedev and Derek Muller
Camera operation by Raquel Nuno
Additional research by Gregor Čavlović
Edited by Jack Saxon and Trenton Oliver
Animated by Fabio Albertelli, Jakub Misiek, Ivy Tello, David Szakaly and Will Wood
Produced by Will Wood, Han Evans and Derek Muller

Thumbnail by Ren Hurley
Additional video/photos supplied by Getty Images and Pond5
Music from Epidemic Sound

If you ran evolution all over again, would you get humans? How repeatable is #evolution? This video is sponsored by @BountyBrand. #biology #science #QPU #HygieneBeginswithBounty #BountyPartner

Special thanks to Prof. Richard Lenski and team for showing me around the lab — it is an honor to be able to witness and document such a historic science experiment.
Thanks to Dr Zachary Blount for the help with research and setting up the competition time-lapse, Dr Nkrumah Grant for microscope images of the long-term line cells @NkrumahGrant
Devin Lake, Kate Bellgowan, and Dr. Minako Izutsu for being part of this video. Long Live the LTEE!

LTEE website — http://myxo.css.msu.edu/ecoli/index.html
Intro footage courtesy of the Kishony Lab — https://kishony.technion.ac.il
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References:
Lenski, R. E., & Travisano, M. (1994). Dynamics of adaptation and diversification: a 10,000-generation experiment with bacterial populations. Proceedings of the National Academy of Sciences, 91(15), 6808-6814. — https://ve42.co/Lenski1994

Lenski, R. E., Rose, M. R., Simpson, S. C., & Tadler, S. C. (1991). Long-term experimental evolution in Escherichia coli. I. Adaptation and divergence during 2,000 generations. The American Naturalist, 138(6), 1315-1341. — https://ve42.co/Lenski1991

Good, B. H., McDonald, M. J., Barrick, J. E., Lenski, R. E., & Desai, M. M. (2017). The dynamics of molecular evolution over 60,000 generations. Nature, 551(7678), 45-50. — https://ve42.co/Good2017

Blount, Z. D., Borland, C. Z., & Lenski, R. E. (2008). Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli. Proceedings of the National Academy of Sciences, 105(23), 7899-7906. — https://ve42.co/Blount2008

Blount, Z. D., Lenski, R. E., & Losos, J. B. (2018). Contingency and determinism in evolution: Replaying life’s tape. Science, 362(6415). — https://ve42.co/Blount2018

Wiser, M. J., Ribeck, N., & Lenski, R. E. (2013). Long-term dynamics of adaptation in asexual populations. Science, 342(6164), 1364-1367. — https://ve42.co/Wiser2013

N, Scharping. (2019). How a 30-Year Experiment Has Fundamentally Changed Our View of How Evolution Works. Discover — https://ve42.co/Scharping

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Special thanks to Patreon supporters: Mike Tung, Evgeny Skvortsov, Meekay, Ismail Öncü Usta, Paul Peijzel, Crated Comments, Anna, Mac Malkawi, Michael Schneider, Oleksii Leonov, Jim Osmun, Tyson McDowell, Ludovic Robillard, Jim buckmaster, fanime96, Juan Benet, Ruslan Khroma, Robert Blum, Richard Sundvall, Lee Redden, Vincent, Marinus Kuivenhoven, Alfred Wallace, Arjun Chakroborty, Joar Wandborg, Clayton Greenwell, Pindex, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi, Ron Neal

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Research and Writing by by Derek Muller, Petr Lebedev and Casey Rentz
Animation by Ivy Tello
Filmed by Derek Muller, Emily Zhang and Raquel Nuno
Edited by Derek Muller
Music by Jonny Hyman and from Epidemic Sound https://epidemicsound.com
Additional video supplied by Getty Images
Thumbnail image courtesy of the Kishony Lab
Produced by Casey Rentz
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Does light take all possible paths at the same time? 🌏 Get exclusive NordVPN deal here ➵ https://NordVPN.com/veritasium It’s risk free with Nord’s 30 day money-back guarantee!✌

A massive thank you to Dr. Andrew Mitchell for all his help and expertise. If you want to delve further into this topic then we highly recommend his lecture on Classical physics derived from quantum mechanics: https://www.youtube.com/watch?v=2iuLwWDYC4U&t=1s

We’re incredibly grateful to Prof. David Kaiser, Prof. Steven Strogatz, Prof. Geraint F. Lewis, Elba Alonso-Monsalve, Prof. Christopher S. Baird, Prof. Anthony Bloch, and Prof. Stephen Bartlett for their invaluable contributions to this video.

A special thanks to Mahesh Shenoy from FloatHeadPhysics for his help with this video. Check out his excellent intuitive video on the UV Catastrophe here (Sep 2024): https://www.youtube.com/watch?v=ALEDjjAVZSY

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

▀▀▀
0:00 What path does light travel?
2:40 Black Body Radiation
6:47 How did Planck solve the ultraviolet catastrophe?
9:42 The Quantum of Action
13:25 De Broglie’s Hypothesis
15:16 The Double Slit Experiment
20:00 How Feynman Did Quantum Mechanics
25:01 Proof That Light Takes Every Path
31:16 The Theory of Everything

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Sign up to our Patreon to watch the Q&A for free: https://www.patreon.com/c/veritasium

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

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References:
Armin Hermann (Nov 1974). The Genesis of Quantum Theory (1899-1913). - https://ve42.co/genquanttheor
Richard P. Feynman (1985). QED The Strange Theory of Light and Matter. - https://ve42.co/qed
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
PBS Space Time. (Nov 2021) - https://www.youtube.com/watch?v=Q_CQDSlmboA
Sabine Hossenfelder. (May 2022) - https://www.youtube.com/watch?v=A0da8TEeaeE
Max Planck (1901). On the Law of Distribution of Energy in the Normal Spectrum. Annalen der Physik - https://ve42.co/lawdistenergy
Paul Ehrenfest (1911). Welche Züge der Lichtquantenhypothese spielen in der Theorie der Wärmestrahlung eine wesentliche Rolle?. Wiley Online Library - https://ve42.co/quantthermrad
Nils-Erik Bomark and Reidun Renstrøm (Aug 2023). The Ultraviolet myth. Proceedings of Science - https://ve42.co/uvmyth
Planck's law. In Wikipedia - https://ve42.co/planckslaw
PBS Space Time. (Jul 2017). - https://www.youtube.com/watch?v=vSFRN-ymfgE&t=10s
Einstein and The Photoelectric Effect. (Jan 2005) via APS News - https://ve42.co/einsteinphotoelec
Louis de Broglie (1924). On the Theory of Quanta. - https://ve42.co/theoryquanta
Larry Sorensen (2012). Path Integrals 1. University of Washington - https://ve42.co/pathintegrals
Feynman’s Method of “A Particle Exploring All Possible Paths”. (Mar 2018) via Pure Dhamma - https://ve42.co/allposspaths

Additional References - https://ve42.co/AdditionalReferences-PoLA2

Images & Video:
Nobistor Altona 1880 via NDR - https://ve42.co/streetlight
Edison incandescent lights by William J. Hammer via Wikimedia Commons - https://ve42.co/edinclights
The full expanded form of the Standard Model Lagrangian by Chen Ning Yang et al. via Wikipedia - https://ve42.co/stmodellang
Muon Ray. (2011). https://www.youtube.com/watch?v=-QUj2ZRUa7c
Muon Ray. (2011). https://www.youtube.com/watch?v=1C7abO7LtV0
Bohrs Atomic Model via EEEGUIDE.COM - https://ve42.co/bohrmodel

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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, Juan Benet, Keith England, KeyWestr, Kyi, Lee Redden, Marinus Kuivenhoven, Matthias Wrobel, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, qiaohui wei, Richard Sundvall, Sam Lutfi, Tj Steyn, TTST, Ubiquity Ventures, wolfee

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Directed by Casper Mebius
Written by Casper Mebius and Derek Muller
Edited by Trenton Oliver and Peter Nelson
Animated by Fabio Albertelli, Mike Radjabov, Ivy Tello, Andrew Neet and Emma Wright
Illustrations by Jakub Misiek, Tommy A. Steven and Cainejan Esperanza
Filmed by Derek Muller and Casper Mebius
Produced by Casper Mebius, Derek Muller, Rob Beasley Spence, Gabe Strong, Geeta Thakur, Emilia Gyles, Zoe Heron, Emily Zhang and Tori Brittain

Thumbnail contributions by Ignat Berbeci, Ben Powell, Jakub Misiek, Ren Hurley, and Peter Sheppard

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