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

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.

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

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.

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. 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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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, 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

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:
Tj Steyn, Meg Noah, Bernard McGee, James Sanger, Elliot Miller, Jerome Barakos M.D., Amadeo Bee, TTST, Balkrishna Heroor, Chris LaClair, John H. Austin Jr., Eric Sexton, John Kiehl, Anton Ragin, Diffbot, Gnare, Dave Kircher, Burt Humburg, Blake Byers, Evgeny Skvortsov, Meekay, Bill Linder, Paul Peijzel, Josh Hibschman, Mac Malkawi, 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
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

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

IQ is supposed to measure intelligence, but does it? 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.

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 Emeritus Professor Cecil R. Reynolds and Dr. Stuart J. Ritchie for their expertise and time.

Also a massive thank you to Prof. Steven Piantadosi and Prof. Alan S. Kaufman for helping us understand this complicated topic. As well as to Jay Zagrosky from Boston University's Questrom School of Business for providing data from his study.

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References:
Kaufman, A. S. (2009). IQ testing 101. Springer Publishing Company.

Reynolds, C. R., & Livingston, R. A. (2021). Mastering modern psychological testing. Springer International Publishing.

Ritchie, S. (2015). Intelligence: All that matters. John Murray.

Spearman, C. (1961). " General Intelligence" Objectively Determined and Measured. - https://ve42.co/Spearman1904

Binet, A., & Simon, T. (1907). Le développement de l'intelligence chez les enfants. L'Année psychologique, 14(1), 1-94.. - https://ve42.co/Binet1907

Intelligence Quotient, Wikipedia - https://ve42.co/IQWiki

Radiolab Presents: G. - https://ve42.co/RadioLabG

McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33(4), 337-346. - https://ve42.co/McDaniel2005

Deary, I. J., Strand, S., Smith, P., & Fernandes, C. (2007). Intelligence and educational achievement. Intelligence, 35(1), 13-21. - https://ve42.co/Deary2007

Lozano-Blasco, R., Quílez-Robres, A., Usán, P., Salavera, C., & Casanovas-López, R. (2022). Types of Intelligence and Academic Performance: A Systematic Review and Meta-Analysis. Journal of Intelligence, 10(4), 123. - https://ve42.co/Blasco2022

Kuncel, N. R., & Hezlett, S. A. (2010). Fact and fiction in cognitive ability testing for admissions and hiring decisions. Current Directions in Psychological Science, 19(6), 339-345. - https://ve42.co/Kuncel2010

Laurence, J. H., & Ramsberger, P. F. (1991). Low-aptitude men in the military: Who profits, who pays?. Praeger Publishers. - https://ve42.co/Laurence1991

Gregory, H. (2015). McNamara's Folly: The Use of Low-IQ Troops in the Vietnam War; Plus the Induction of Unfit Men, Criminals, and Misfits. Infinity Publishing.

Gottfredson, L. S., & Deary, I. J. (2004). Intelligence predicts health and longevity, but why?. Current Directions in Psychological Science, 13(1), 1-4. - https://ve42.co/Gottfredson2004

Sanchez-Izquierdo, M., Fernandez-Ballesteros, R., Valeriano-Lorenzo, E. L., & Botella, J. (2023). Intelligence and life expectancy in late adulthood: A meta-analysis. Intelligence, 98, 101738. - https://ve42.co/Izquierdo2023

Zagorsky, J. L. (2007). Do you have to be smart to be rich? The impact of IQ on wealth, income and financial distress. Intelligence, 35(5), 489-501. - https://ve42.co/Zagorsky2007

Strenze, T. (2007). Intelligence and socioeconomic success: A meta-analytic review of longitudinal research. Intelligence, 35(5), 401-426. - https://ve42.co/Strenze2007

Deary, I. J., Pattie, A., & Starr, J. M. (2013). The stability of intelligence from age 11 to age 90 years: the Lothian birth cohort of 1921. Psychological science, 24(12), 2361-2368. - https://ve42.co/Deary2013

Flynn, J. R. (1987). Massive IQ gains in 14 nations: What IQ tests really measure. Psychological bulletin, 101(2), 171. - https://ve42.co/Flynn1987

Why our IQ levels are higher than our grandparents' | James Flynn, TED via YouTube - https://www.youtube.com/watch?v=9vpqilhW9uI

Duckworth, A. L., Quinn, P. D., Lynam, D. R., Loeber, R., & Stouthamer-Loeber, M. (2011). Role of test motivation in intelligence testing. Proceedings of the National Academy of Sciences, 108(19), 7716-7720. - https://ve42.co/Duckworth2011

Kulik, J. A., Bangert-Drowns, R. L., & Kulik, C. L. C. (1984). Effectiveness of coaching for aptitude tests. Psychological Bulletin, 95(2), 179. - https://ve42.co/Kulik1984

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Special thanks to our Patreon supporters:
Adam Foreman, Amadeo Bee, Anton Ragin, Balkrishna Heroor, Benedikt Heinen, Bernard McGee, Bill Linder, Burt Humburg, Dave Kircher, Diffbot, Evgeny Skvortsov, Gnare, John H. Austin, Jr., john kiehl, Josh Hibschman, Juan Benet, KeyWestr, Lee Redden, Marinus Kuivenhoven, 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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Written by Derek Muller, Casper Mebius, & Petr Lebedev
Edited by Trenton Oliver
Filmed by Derek Muller, Han Evans, & Raquel Nuno
Animation by Fabio Albertelli & Ivy Tello
Additional video/photos supplied by Getty Images & Pond5
Music from Epidemic Sound
Produced by Derek Muller, Casper Mebius, & Han Evans

How the brain works, how we learn, and why we sometimes make stupid mistakes.
Submit ideas: http://ve42.co/GotIdeas
Apply to work with me: http://ve42.co/JoinUs

Thanks to Patreon supporters:
Nathan Hansen, Donal Botkin, Tony Fadell, Zach Mueller, Ron Neal

Support Veritasium on Patreon: http://bit.ly/VePatreon

This video was inspired by the book Thinking Fast and Slow by Daniel Kahneman

Harpist: Lara Somogyi http://ve42.co/Lara
Animator: Jesse Agar http://ve42.co/ThisPlace
Filmed by Raquel Nuno

Music by Kevin MacLeod, http://incompetech.com "Sneaky Adventure" "Harlequin"

Key aspects of pyramid construction from quarry to completion.
Check out Audible: http://bit.ly/AudibleVe
Live show in Alabama: http://bit.ly/VeRAOI

The most common misconception about the pyramids is that they were built by slaves. Recent archeological evidence suggests they were instead constructed by paid workers. Some may have performed this work as a form of tax payment for several months of the year. Skilled engineers would have planned and orchestrated the building. An estimated 10,000-20,000 people would have been working on a pyramid at any one point in time. They were well fed and provided with shelter near the pyramids. Plus their burial sites close by indicate they were respected and were not slaves.

Much of the limestone was quarried from the Giza plateau itself, meaning the stones did not need to be transported far. The granite casing of Menkaure's pyramid, on the other hand, was transported from Aswan, around 600 miles, or 1000 km up the Nile.

Editing assistance by Dustin Chow

Music by Kevin MacLeod, Incompetech.com "Desert City" and "Ibn Al-Noor"

Droplets levitate on a bath of liquid nitrogen and are spontaneously self-propelled. Thanks Audible! Start a 30-day trial and your first audiobook is free. Go to https://audible.com/VERITASIUM or text VERITASIUM to 500500.

Special thanks to Dr. Anaïs Gauthier
Physics of Fluids: https://pof.tnw.utwente.nl/

Self-propulsion of inverse Leidenfrost drops on a cryogenic bath
Anaïs Gauthier, Christian Diddens, Rémi Proville, Detlef Lohse, and Devaraj van der Meer
PNAS January 22, 2019 116 (4) 1174-1179; published ahead of print January 22, 2019
https://www.pnas.org/content/116/4/1174

For a detailed description of the setup:
http://www.lps.ens.fr/~adda/pa....piers/Langmuir2016.p

And self-propulsion is also seen: http://www.lps.ens.fr/~adda/pa....piers/InvLeidenfrost

Other recent (hot) Leidenfrost experiments that might be interesting:
* Leidenfrost wheels: https://www.youtube.com/watch?v=glRGl-eYuXo
* Leidenfrost maze: https://www.youtube.com/watch?time_continue=174&v=vPZ7sx3EwUY
* Leidenfrost explosions: https://www.youtube.com/watch?v=z0sp3AjgUy4

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

Thanks to Prof. Kevin McKeegan at UCLA for the liquid nitrogen

Filming by Raquel Nuno

Additional animations by Alan Chamberlain

A rare look inside the Svalbard Global Seed Vault which is closed ~350 days a year
Check out Audible: http://bit.ly/AudibleVe
More info on the seed vault: http://wke.lt/w/s/EKFlK
My trip to Norway was funded by Screen Australia, Film Victoria and Genepool Productions as part of a new project. More information soon.

Special thanks to Bente Naeverdal and the Crop Trust: https://www.croptrust.org

A basketball and a 5kg medicine ball are dropped simultaneously. Which one hits the ground first? It seems obvious that the heavy one should accelerate at a greater rate and therefore land first because the force pulling it down is greater. But this is forgetting inertia - the tendency of mass to resist changes in motion. Therefore, although the force on the medicine ball is greater, it takes this larger force to accelerate the ball at the same rate as the basketball.

A recent survey of scientific literacy in Australia found 30% believe it takes one day for the Earth to go around the sun. This video provides qualitative evidence for the finding from Sydney's Eastern beaches.

I always wanted to know why film looked better than video. Moving electronic images have as long a history but were invented for a different purpose. This video was sponsored by B&H Photo: https://www.bhphotovideo.com

Huge thanks to:

Richard Diehl, Video Labguy https://www.youtube.com/user/videolabguy
https://www.labguysworld.com

Branch Education for awesome animations
https://ve42.co/BranchEd

Minutephysics for mechanical TV animations
https://www.youtube.com/minutephysics

Mark Schubin
Engineer and explainer, SMPTE Life Fellow
https://www.smpte.org

This is a video I've long wanted to make, about what makes video look like video and, up until 10 years ago or so, not as appealing as film. I grew up with the two technologies (film and video) in parallel and to me they always seemed like two ways of achieving the same ends: recording and replaying moving images. But their histories are quite distinct. Film was always a way to capture moving images for later replaying. Video started out as a way to transfer images from one place to another instantaneously. This dates back to the first fax machine, mechanical TV, live broadcast tv and ultimately videotapes. This history focuses on the early decades of video and not the more recent switches to chip cameras and solid state storage. Maybe that's a story for another day.

Additional resources and references:

The Dawn of Tape: Transmission Device as Preservation Medium
https://ve42.co/dawnoftape

What Sparked Video Research in 1877? The Overlooked Role of the Siemens Artificial Eye
https://ve42.co/sparkvideo

Video Preservation Website:
http://videopreservation.conservation-us.org

Image Orthicon Tube:
http://interiorcommunicationse....lectrician.tpub.com/

Film vs Digital
https://stephenfollows.com/film-vs-digital/

Eyes of a Generation:
http://eyesofageneration.com

Television in the US:
http://www3.northern.edu/wild/th100/tv.htm

http://www.classictvinfo.com

Music from https://www.epidemicsound.com "Seaweed" "Capture a Picture 1" "Colorful Animation 4"

Even some physics professors say this craft breaks the laws of physics. This video is sponsored by Kiwico, For 50% off your first month of any subscription crate from KiwiCo (available in 40 countries!) head to https://www.kiwico.com/Veritasium50

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A HUGE thanks to Rick and Neil for letting me drive Blackbird. Check out Rick's YouTube Channel for more in depth videos and explanations on going faster than the wind downwind -- https://ve42.co/Rick

Gene Nagata made the shoot possible. If you’re a video nerd like me, check out his channel, Potato Jet: https://www.youtube.com/c/PotatoJet/featured.

Xyla Foxlin for made the model cart used in this video. Xyla builds amazing things like rockets and canoes, check it out! https://www.youtube.com/c/xylafoxlin/

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References
Jack Goodman's YouTube video -- https://ve42.co/Goodman
Rick's treadmill footage -- https://ve42.co/Treadmill
Rick's multiple explanations of how Blackbird works -- https://ve42.co/DDWFTTW
Forum discussions -- https://ve42.co/forum Blog -- https://ve42.co/blog1 and retraction https://ve42.co/BlogRetraction

Gaunaa, M., Øye, S., & Mikkelsen, R. F. (2009). Theory and design of flow driven vehicles using rotors for energy conversion. In EWEC 2009 Proceedings online EWEC

Md. Sadak Ali Khan, Syed Ali Sufiyan, Jibu Thomas George, Md. Nizamuddin Ahmed. Analysis of Down-Wind Propeller Vehicle. International Journal of Scientific and Research Publications, 3, 4. (April 2013) ISSN 2250-3153. (www.ijsrp.org)

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Special thanks to Patreon supporters: Bill Linder, 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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Thanks to James Lincoln for building the initial prototypes for a model blackbird.

Written by Derek Muller, James Lincoln, and Petr Lebedev
Animation by Mike Radjabov and Ivy Tello
Filmed by Gene Nagata, Derek Muller, Trenton Oliver, AJ Fillo and Emily Zhang
Edited by Trenton Oliver
Music from Epidemic Sound https://epidemicsound.com
Additional video supplied by Getty Images
Produced by AJ Fillo

How an SAT question became a mathematical paradox. 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 this list to help us keep our videos free, forever:
https://ve42.co/PatreonDEB

I invented Snatoms, a molecule modeling kit where the atoms snap together magnetically. Try it at https://ve42.co/SnatomsV

Huge thanks to Dr. Doug Jungreis for taking the time to speak with us about this SAT question.
Thanks to Stellarium, a wonderful free astronomy simulator – https://ve42.co/Stellarium
Thanks to Newspapers.com, a database of historical newspapers – https://ve42.co/Newspapers

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References:
Summary of this problem by MindYourDecisions – https://www.youtube.com/watch?v=kN3AOMrnEUs
More cool math about this problem by Kyle Hill – https://www.youtube.com/watch?v=_zCDbB9wvrc
Discussion of a solar day by MinutePhysics – https://www.youtube.com/watch?v=nZMMuv0Ltyo
Murtagh, J. (2023). The SAT Problem That Everybody Got Wrong. Scientific American – https://ve42.co/SATSciAm
United Press International (1982). Error Found in S.A.T. Question. New York Times – https://ve42.co/SAT-NYT
Yang (2020). What's the hardest SAT math problem that you've seen? Quora – https://ve42.co/SATQuora
Coin rotation paradox via Wikipedia – https://ve42.co/CoinParadox
Simmons, B. (2015). Circle revolutions rolling around another circle. MathStackExchange. – https://ve42.co/CircleRoll
Sidereal time via Wikipedia – https://ve42.co/SiderealWiki
Solar Time vs. Sidereal Time via Las Cumbres Observatory – https://ve42.co/SiderealLCO

Images & Video:
Zotti, G., et al. (2021). The Simulated Sky: Stellarium for Cultural Astronomy Research - https://ve42.co/Stellarium
Newspapers from 1980s - 1990s via Newspapers.com – https://ve42.co/Newspapers
SAT Practice Test via the College Board – https://ve42.co/PracticeSAT
Revolution Definition via NASA – https://ve42.co/RevolutionNASA
Revolution Definition via Merriam-Webster – https://ve42.co/RevolutionWebster
Earth motion animation via NASA – https://ve42.co/OrbitNASA
Satellite animation via NASA – https://ve42.co/SatNASA

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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 Emily Zhang
Written by Emily Zhang and Gregor Čavlović
Edited by Peter Nelson
Animated by Ivy Tello and Fabio Albertelli
Filmed by Derek Muller
Produced by Emily Zhang, Han Evans, Gregor Čavlović, and Derek Muller

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

Scientists like Prof Sinclair have evidence of speeding up, slowing, and even reversing aging.
Thanks to LastPass for sponsoring this video. Click here to start using LastPass: https://ve42.co/VeLP

What causes aging? According to Professor David Sinclair, it is a loss of information in our epigenome, the system of proteins like histones and chemical markers like methylation that turn on and off genes. Epigenetics allow different cell types to perform their specific functions - they are what differentiate a brain cell from a skin cell. Our DNA is constantly getting broken, by cosmic rays, UV radiation, free radicals, x-rays and regular cell division etc. When our cells repair that damage, the epigenome is not perfectly reset. And hence over time, noise accumulates in our epigenome. Our cells no longer perform their functions well.

To counter this decline, we can activate the body's own defenses against aging by stressing the body. Eat less, eat less protein, engage in intense exercise, experience uncomfortable cold. When the body senses existential threats it triggers longevity genes, which attempt to maintain the body to ensure its survival until good times return. This may be the evolutionary legacy of early bacteria, which established these two modes of living (repair and protect vs grow and reproduce). Scientists are uncovering ways to mimic stresses on the body without the discomfort of fasting. Molecules like NMN also trigger sirtuins to monitor and repair the epigenome. This may slow aging.

Reversing aging requires an epigenetic reset, which may be possible using Yamanaka factors. These four factors can revert an adult cell into a pluripotent stem cell. Prof. Sinclair used three of the four factors to reverse aging in the retinal cells of old mice. He found they could see again after the treatment.

Special thanks to:
Professor David Sinclair, check out his book "Lifespan: Why We Age & Why We Don't Have To"
Assistant Professor David Gold
Noemie Sierra (for polyp images)
Genepool Productions for telomere animations from Immortal: https://ve42.co/immortal
Epigenetics animations (DNA, histones, methylation etc) courtesy of: http://wehi.tv
Animation: Etsuko Uno
Art and Technical Direction: Drew Berry
Sound Design: Francois Tetaz & Emma Bortignon
Scientific Consultation: Marnie Blewitt
Courtesy of Walter and Eliza Hall Institute of Medical Research

Filming, editing and animation by Jonny Hyman and Derek Muller

Music from https://epidemicsound.com "Clearer Views" "Innovations" "A Sound Foundation" "Seaweed"
Additional music by Kevin MacLeod from https://incompetech.com "Marty Gots a Plan"

I got the chance to interview Bill Gates so I asked him: Will Covid-19 be the last pandemic? How does he deal with misinformation and conspiracy theories? And what is the next disaster? The Foundation Letter is here: https://ve42.co/BG21

Special thanks to Patreon supporters:
Ludovic Robillard, jim buckmaster, Robert, fanime96, Marc Forand, Juan Benet, Robert Blum, Grace O'Maille KRON x Arc iOS, 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

Thanks to Petr Lebedev for the thumbnail, early edits and Jonny Hyman for feedback

Space junk is a real problem. NASA now tracks around 20,000 pieces of debris orbiting Earth, most of them larger than 10cm across. Since the average speed of a collision between orbiting objects is 10 km/s these pieces of trash can cause a lot of damage despite their small size.

Scientists in Switzerland have a plan to clean up space junk - it involves creating a 'Janitor Satellite' that will seek out pieces of space junk to drag back into the atmosphere causing them to burn up.

This video was created for the Aussie science show Catalyst on the ABC: http://www.abc.net.au/catalyst

The total solar eclipse from Madras, Oregon on August 21, 2017. As the moon passed in front of the sun turning day to night and revealing the sun's corona, apparently all I could think to say was 'Oh my goodness!'

This awe-inspiring phenomenon returned to the US on April 8, 2024, when total solar eclipse crossed North America, passing over Mexico, the United States, and Canada.

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

Everyone says not to photograph your first solar eclipse and I think they might be right. I was focused on getting the exposure right for Bailey's beads and the diamond ring, plus making sure to get the corona and solar flares. This was a bit stressful but I'm delighted with the results.

This video originally included more info but since I'm uploading from Madras where the internet is sluggish, I cut out three minutes so the upload would happen before I had to leave for my flight.

Special thanks also to Dr. Teagan Wall for sharing this experience with me and Raquel Nuno for inspiring me to come to Oregon.

Music from http://epidemicsound.com "Spinning Earth 2" and
Kevin MacLeod http://incompetech.com "Big Mojo"