When evolution favours a stable ratio of traits rather than one dominant trait.
Check out Audible: http://bit.ly/AudibleVe
Animation by The Lyosacks: https://www.youtube.com/TheLyosacks

Hosting Neil Degrasse Tyson, info and tickets: http://bit.ly/NDTandVe
Aug. 22 in Sydney
Aug. 23 in Canberra

Special thanks to Richard Dawkins

Filmed at Academia Film Olomouc with help from Martyn Marek

Music by Kevin MacLeod www.incompetech.com 'Marty Gots a Plan' 'Sing Along with Jim'

The truth, with photons.
I hope I've articulated everything clearly in this video. If not, I'll clarify in comments. Thanks to everyone who appears in this video and thanks to everyone who watches this video!

Veritasium is of course a combination of the latin 'veritas' meaning truth, and the common element ending 'ium'. I guess this is my version of the 'draw my life' craze that rolled through YouTube many years ago. Except I wanted to tell my story with the actual moments, the photons, the stored magnetic states. There's something about that which is so important to me (because I think the alternative involves fooling yourself) which is why I'm so fascinated by film and video.

One of my inspirations for the name Veritasium came from the end of the poem Ode on a Grecian Urn by John Keats, in which he writes:
"Beauty is truth, truth beauty,—that is all
Ye know on earth, and all ye need to know."

Special thanks to Patreon supporters:
Tony Fadell, Donal Botkin, Michael Krugman, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen, Yildiz Kabaran,
Terrance Snow, Stan Presolski

Music from http://epidemicsound.com
Magnified X1 - Gunnar Johnsen
Fluorescent Lights - Martin Gauffin
Dissolving Patterns - Ebb & Flod
Luna - Ebb & Flod

Additional music by Kevin MacLeod: http://incompetech.com
Sneaky Snitch

Common pitfalls of New Year's resolutions and how I plan to avoid them. Thanks Audible! Start listening with a 30-day trial and your first audiobook plus two Audible Originals free when you go to https://audible.com/veritasium or text veritasium to 500500.

Thanks to Simone Giertz for sending me and Every Day Calendar!
Get notified when they're available to order here: http://www.simonegiertz.com/every-day-calendar

Special thanks to Patreon Supporters:
Alfred Wallace, Arjun Chakroborty, Chuck Lauer Vose, Dale Horne, Jasper Xin, Joar Wandborg, Kevin Beavers, Leah Howard, Lyvann Ferrusca, Michael Krugman, Noel Braganza, Ron Neal, Tige Thorman

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"

How do you measure big forces accurately? By calibrating your force transducer on the world's biggest weight - 1,000,000 pounds of force. This machine ensures planes don't break apart, jets provide required thrust, and rockets make it to their destination.

Thanks to the people at NIST for showing me around: Rick Seifarth and Ben Stein. Animations here are by Sean Kelley and additional footage by Jennifer Lauren Lee.

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

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

Before visiting NIST in Washington DC I had no idea machines like this existed. Surely there's an accurate way to measure forces without creating such a huge known force?! Nope. This appears to be the best way, with a stack of 20 x 50,000 lb masses creating a maximum force of 4.45 MN or 1,000,000 pounds of force. I also wouldn't have thought about all the corrections that need applying - for example buoyancy subtracts about 125 pounds from the weight of the stack. Plus the local gravitational field strength must be taken into account. And, the gravitational field varies below grade. All of this must be taken into account in order to limit uncertainty to just five parts per million (.0005%)

Music from The Epidemic Sound http://epidemicsound.com "Serene Story 2"

Learn how you can help reduce global warming → https://globalwarmingeffect.org
Common misconceptions about climate change.
Check out Audible: http://bit.ly/AudibleVe
References below:

For CO2, sea levels, Arctic sea ice, Antarctic and Greenland land ice:
http://climate.nasa.gov

Satellite data shows that ground-based stations underestimate recent warming: Cowtan and Way, 2014
http://onlinelibrary.wiley.com..../doi/10.1002/qj.2297

For papers published on climate change during the 1970's, see Peterson, 2008
http://ams.confex.com/ams/pdfpapers/131047.pdf

For solar and temperature data see NASA GISS,
PMOD: http://www.acrim.com/tsi%20monitoring.htm
Krivova et al. 2007:
http://www2.mps.mpg.de/project....s/sun-climate/data.h

CO2 ratio of Carbon-13:Carbon-12 decreasing. IPCC AR4:
http://www.ipcc.ch/publication....s_and_data/ar4/wg1/e

CO2 emitted by volcanoes vs by humans: Gerlach, 2011
www.agu.org/pubs/pdf/2011eo240001.pdf Gerlach

Mauna Loa CO2 data: http://www.esrl.noaa.gov/gmd/ccgg/trends/

Rising atmospheric water vapour: Santer, 2007
http://www.pnas.org/cgi/reprint/0702872104v1.pdf

A doubling of CO2 will likely lead to a 3C increase in global temperatures according to many independent pieces of evidence:
Knutti & Hegerl, 2008
http://www.iac.ethz.ch/people/....knuttir/papers/knutt

Great resource on Milankovitch cycles:
http://www.sciencecourseware.o....rg/eec/GlobalWarming

CO2 lags temperature rise in the southern hemisphere but leads the global average temperature rise, Shakun et al. 2012
http://www.nature.com/nature/j....ournal/v484/n7392/ab

Music by Kevin McLeod, http://incompetech.com Songs: Hidden Agenda, Sneaky Snitch, Harlequin

The Mars Helicopter aims to make the first powered flight on another planet when it takes off on Mars as part of the Mars 2020 mission. I learned a lot getting to visit the drone right before it was mounted on the rover.

How do you fly in 1% of Earth's atmosphere:
Have large rotors (they are 1.2m in diameter) and spin them very fast, around 2500 RPM (5x the speed of a helicopter on Earth).

Plus the aircraft has to be light:
The Mars helicopter weighs in at 1.8kg or around the same as a laptop. Every piece had to be stripped down for weight. Instead of using aerogel for insulation, the craft makes use of CO2 gaps between components. Even aerogel was too heavy!

One of the major challenges is surviving the Martian night:
Temperatures plunge to -80C to -100C so two thirds of the craft's power is actually used to keep its electronics warm. Only one third is used for flying. The estimated flight time is 90 seconds.

The craft can't be driven remotely, it will have to fly autonomously, using its own sensor suite to determine how to fly. The round trip 20 minute delay with Earth means steering the craft from mission control would be impossible.

Huge Thanks to Patreon Supporters:
Philipp Volgger, Chris Vargas, Ron Neal, Alfred Wallace, Colin Bellmore, Michael Krugman, James Knight, Donal Botkin, Sam Lutfi, Mohammed Al Sahaf, Kevin Beavers, Chuck Lauer Vose, Bryan Baker, James Wong, kkm, Manuel Zürcher, Tige Thorman, Jasper Xin, Leah Howard, Daniel Milum, Mathias Göransson, Stan Presolski, Lyvann Ferrusca, Arjun Chakroborty, June Kang, Listen Money Matters, Pindex, Joar Wandborg, DALE HORNE, Parker Linn, Roberto Rezende

Jonny Hyman was a legend in editing, animation, filming, and sound design for this video.

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!'

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

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"

If you drop a heavy object and a light object simultaneously, which one will reach the ground first? A lot of people will say the heavy object, but what about those who know both will land at the same time? What do they think? Some believe both objects have the same gravitational pull on them and/or both fall to the ground with the same constant speed. Neither of these things is true, however. The force is greater on the heavy object and both objects accelerate at the same rate as they approach the earth, i.e. they both speed up but at the same rate.

On the surface of Earth all objects accelerate downwards at the same rate - at least, they're supposed to. But we all know dust, pieces of paper, and feathers fall slower. This is of course due to the influence of air resistance. In this experiment we use an evacuated cylinder to test whether a coin and feather really do accelerate at the same rate.

In 2020, NASA will send a new rover to the Martian surface with one of its objectives to search for evidence of ancient life on the planet. 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"

Standing waves of fire!
Check out Audible: http://bit.ly/AudibleVe
Fysikshow: http://bit.ly/Fysikshow - I'm hosting Michio Kaku in Melbourne ONLY: http://bit.ly/VeKakuTickets

Rubens' Tube is an awesome demo and here we take it to the next level with a two-dimensional 'Pyro Board'. This shows unique standing wave patters of sound in the box.

The pressure variations due to the sound waves affect the flow rate of flammable gas from the holes in the Pyro Board and therefore affect the height and colour of flames. This is interesting for visualizing standing wave patterns and simply awesome to watch when put to music. Thank you to Sune Nielsen and everyone at Aarhus for sharing this demonstration with me! And thanks for having me at your conference.

Music by Kevin MacLeod, www.Incompetech.com "Ice Flow"

The story of three impressive high school science projects. Can you guess which student won $250,000 in the #RegeneronSTS? Applications open June 1: http://bit.ly/2HkLXT1 This video was sponsored by Regeneron. The Science Talent Search was founded and produced by the Society for Science and the Public.

Huge thanks to the students: Ronak Roy, Ana Humphrey, and Anjali Chadha. It was great getting to meet all of you and learn about your original scientific research.

Special thanks to Assistant Professor Konstantin Batygin for discussing Ana's research and Planet 9 with me. More is coming on the Planet 9 front.

Ronak came up with a new design for the phoropter, the device used to determine eye-glass prescriptions. It's basically been unchanged for 200 years. Using a liquid lens, he miniaturized the device and wrote an algorithm to determine your prescription.

Ana used math and physics to search for hidden exoplanets. There are a number of reasons why the transit method and Kepler telescope may have missed them: they're too small, too inclined, or take too long to orbit and so were not seen. By considering which planetary systems have additional space for more planets, Ana came up with 560 locations where we may look again for planets in future.

Anjali developed an internet enabled device for measuring arsenic concentrations in drinking water. The device performs several chemical reactions to release the arsenic into a measurable state. It then reacts the arsenic with a test strip to produce a color output. This color is sampled by a camera and processed to determine the concentration of arsenic in the water sample. This has significant potential applications around the world helping reduce exposure to arsenic and potentially other contaminants.

Filming by Raquel Nuno

To see what this looks like from under a glass table, see http://www.youtube.com/watch?v=E9WUaBGH7_I

I took a boat through 96 million black plastic balls on the Los Angeles reservoir to find out why they're there. The first time I heard about shade balls the claim was they reduce evaporation. But it turns out this isn't the reason they were introduced.

Huge thanks to LADWP for arranging this special tour for me. Next time let's put the GoPro on the submersible!

The balls are made of high density polyethylene (HDPE) which is less dense than water so they float on the surface of the reservoir even if they break apart. They are 10cm (4 inches) in diameter and contain about 210ml of water. So the main reason they are on the reservoir is to block sunlight from entering the water and triggering a chemical reaction that turns harmless bromide into carcinogenic bromate. This effect occurs with prolonged exposure to bromate so regulators insist that levels be kept below 10 microgram per liter on average over a 12 month period.

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.

Thanks to:
Las Virgenes Reservoir for footage of initial shade ball dump
Euro-Matic for bird into jet-engine footage

Researched and Produced by Casey Rentz

Animations by Maria Raykova

Music from http://epidemicsound.com "Colorful Animation 4" "Seaweed"

And from Kevin MacLeod "Marty Gots a Plan"

This is an educational video about the science of water quality.

I got to drive the world's first car (replica), patented by Benz in 1886
Check out the series on new safety features: http://ve42.co/MB
This video is sponsored by Mercedes-Benz, who invited me to come to Stuttgart to see their latest cars, crash test facilities and experience the innovations they are working on.

Physics is something that is directly applicable to car safety. Cars go fast, but they also sometimes collide with obstacles, which brings them to a sudden stop, subjecting the car and occupants to very high accelerations, which can cause injury or death. So the major idea to improve car safety is to reduce these accelerations and there are a number of ways to do this:

Passive safety:

Seat belts: keep passengers in the vehicle, preventing them from continuing with constant velocity, flying through the windshield and suffering a worse deceleration when they make contact with the road.

Crumple zones: increase the distance over which deceleration occurs, thereby reducing peak magnitude of deceleration.

Air bags: increase the distance over which the head decelerates, again reducing peak magnitude of deceleration of the head.

Active Safety:
Anti-lock braking system: rather than 'locking' the wheels as can happen if you slam on the brakes with a traditional braking system leading to the tires skidding across the road, ABS attempts to control the amount of braking so that the tires always roll with static friction in contact with the road. This increases the backward frictional force that can be applied to the tires, again increasing the distance over which deceleration occurs, and it gives the driver an opportunity to steer to avoid the collision (hence why it's referred to as an active safety system).

Special thanks to Mercedes for having me visit facilities in Stuttgart. I had a lot of fun making these videos so please do check out the series on Mercedes Benz's channel: http://ve42.co/MB

Filmed by Simon Schneider
Edited by Hoplite Creative and Trevor Carlee

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/

A quote by Einstein: A human being is a part of the whole, called by us "Universe", a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest — a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody is able to achieve this completely, but the striving for such achievement is in itself a part of the liberation and a foundation for inner security.

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Happy Geek Week! http://bit.ly/16wdDuk

Everyone has played with a mixture of corn starch and water (or at least I hope they have). This was one of my favorite experiments as a kid. Your hand slides into the slime easily when moving slowly but the mixture behaves as a solid if you hit it quickly. That is what is meant by 'non-Newtonian' - the fluid's properties change depending on its relative motion. These properties can be exploited to dramatic effect as has been shown on speaker cones before. Here I wanted to understand what is going on, what frequencies and amplitudes work best so I used a slow-mo camera.

Thanks to everyone at the YouTube Space LA for helping me film this. I couldn't have done it without you.

Music licensed from http://www.cuesongs.com
Love Lost (Instrumental) by Temper Trap
A Life in the Day by Ghost of Otis
Fortune's Fool Instrumental by Hiatus & Shura
The Man by Audio Android

Innovative research conducted in Lausanne, Switzerland has shown that a combination of neurotransmitters and electrical stimulation can restore movement to the lower limbs of previously paralysed rats. But in order for this motion to be made voluntarily the rats must be motivated to walk. This motivation comes in the form of cheering, visual cues, and of course, chocolate.

Why Trees Are Amazing: http://bit.ly/TFilQ8
Space Junk: http://bit.ly/XlLdjG
Why Astronauts Are Weightless: http://bit.ly/SuF2p1
Higgs Boson Update: http://bit.ly/Vw1Sgu