Higher: http://bit.ly/blockhigher
Same height: http://bit.ly/SameHeight
Lower: http://bit.ly/BlockLower

Special Thanks to:
Henry (MinutePhysics): http://www.youtube.com/minutephysics
Destin (Smarter Every Day): http://www.youtube.com/smartereveryday
Greg and Mitch (ASAP Science): http://youtube.com/asapscience
Elise Andrew (I F***ing Love Science): http://youtube.com/iflscience

Thanks to everyone at RIT and Dickinson College who helped with the making of this video:
Rochester Institute of Technology
Robert Teese, Katelyn Wilkerson, Andrew Gillie, Andrew Stidwill

Dickinson College
This experiment was the brainchild of David Jackson based on a demo at Princeton.
Priscilla Laws, Catrina Hamilton-Drager, Maxine Willis

High-speed camera support:
Charles Zwemer and Bria Antoine

When a tube spins with an X and an O labelled at either end, why do we see only one letter during the rotation?

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"

Why does shaken soda explode? Does ice melt first in fresh or salt water?
Thank you Squarespace for sponsoring this video. Go to https://squarespace.com to save 10% off your first purchase of a website or domain using code: VERITASIUM

This video features experiments that have been shown to me by science teachers over the years. Does ice melt fast in salt water or fresh water was an experiment introduced to me at the Utah Science Teachers' conference. The ring of metal over a chain demo came from a teachers event in Florida. The idea shaking a carbonated drink increases pressure came from an email.

Special thanks to Petr Lebedev for building the pressure gauge.

Links to literature are below:
Victims of the pop bottle, by Ted Willhoft. New Scientist, 21 August 1986 p.28

Carbonation speculation
The Physics Teacher 30, 173 (1992); https://doi.org/10.1119/1.2343501

Agitation solution
The Physics Teacher 30, 325 (1992); https://doi.org/10.1119/1.2343556

Filmed by Cristian Carretero, Jordan Schnabel, Jonny Hyman, and Raquel Nuno

Music from https://epidemicsound.com "Seaweed" "Quietly Tense" "Mind Shift" "Observations"

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

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

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

Boredom makes you more creative, altruistic, introspective, and helps with autobiographical planning.
This video was sponsored by LastPass: http://bit.ly/2wAsdUu

I feel like this video might come across as condescending but the person I'm really talking to is myself. Despite the fact that I know how useful it can be to be bored, I still find myself trying to fill every last moment with stimulus. Boredom is unpleasant - the open, unstructured thinking that can take place can also feel pointless. But now I'm made this video to remind myself how important boredom is so hopefully I'll make more time to be bored.

More resources:

The boredom leads people to shock themselves study:
Just Think: The challenges of the disengaged mind
https://wjh-www.harvard.edu/~d....tg/WILSON%20ET%20AL%

Boredom leads people to consider their future and set goals study:
Back to the future: Autobiographical planning and the functionality of mind-wandering
https://www.sciencedirect.com/....science/article/pii/

On boredom and altruism:
https://pdfs.semanticscholar.o....rg/ca72/0f959d3c9c31

Does boredom make us more creative?
https://www.tandfonline.com/do....i/abs/10.1080/104004

Amazing filming by Raquel Nuno

Music from http://epidemicsound.com "I Think I Was There" "Critical Thinking 2" "Wide Open" "Seaweed" "A Sound Foundation 1"

Music also by Kevin MacLeod http://incompetech.com "Fig Leaf Rag"

Explanation of gyro precession: http://bit.ly/U4e8HQ
More: http://bit.ly/GyroMORE
Less Than: http://bit.ly/GyroLESS
Equal To: http://bit.ly/GyroEQUAL

Huge thanks to A/Prof Emeritus Rod Cross, Helen Georgiou for filming, Alex Yeung, and Chris Stewart, the University of Sydney Mechanical Engineering shop, Duncan and co. Ralph and the School of Physics.

In this video I attempt to lift a 19kg (42 lbs) wheel over my head one-handed while it's spinning at a few thousand RPM. This replicates an earlier experiment by Professor Eric Laithwaite. He claimed the wheel was 'light as a feather' and could not be explained by Newton's Laws. I wanted to find out for myself what I really felt like.

Music By Kevin MacLeod www.Incompetech.com "Tempting Secrets"

In 2018 the kg will be defined by Planck's constant, not a hunk of metal.
Try a free book from Audible for 30 days http://ve42.co/audible
Special thanks to the staff at NIST who made this possible: Darine Haddad, Jon Pratt, Stephan Schlamminger, and Ben Stein.

Additional footage and animations by Sean Kelley, Jennifer Lauren Lee, and Frank Seifert.

I have been obsessed with measurement for a long time and I'm not sure quite how it happened. The world's roundest object played a role in this. I guess I'm just fascinated by how difficult it is to pin down a quantity like a kilogram. A physical object seemed like a good idea until the mass of the international prototype kilogram wasn't as constant as expected. These methods of the Kibble balance and silicon sphere have shown better precision than 20 parts per billion, making them superior to the old method. The agreement between Avogadro approaches

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

Interferometer video by TSG Physics: https://www.youtube.com/watch?v=j-u3IEgcTiQ

Music from http://epidemicsound.com "ExperiMental1" by Gunnar Johnsén

Studio filming by Raquel Nuno

This is what the world would look like if you could see invisible air currents, temperature gradients, and differences in pressure or composition of the air.
Support Veritasium on Patreon: http://ve42.co/patreon

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

I first saw a Schlieren imaging setup around ten years ago in Melbourne. I was immediately fascinated by the way I could see the warm air coming off my hand. I hadn't expected the currents to be moving that fast or to be so visible. This was a tricky setup to get right because alignment is very important and here I'm just working with what I had lying around the house mostly (plus the mirror). For the best Schlieren photography, making sure the mirror is stable is essential. I want to improve my setup so the mirror doesn't wobble back and forth too much creating the pulsing light and dark sections of this video.

The relationship between index of refraction of air and temperature, pressure, humidity and wavelength is complicated. This website will calculate it for you: http://emtoolbox.nist.gov/Wavelength/Ciddor.asp

Slow motion by Hollywood Special Ops: http://www.hollywoodspecialops.com

Sound Effects by A Shell in the Pit: http://www.ashellinthepit.com

Filmed by Raquel Nuno
Special thanks to Blake Nichols for assistance

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

I've created an educational product to help people learn chemistry!
You can buy it here: http://www.snatoms.com

The sun has been producing light for about five billion years but where does all its energy come from? The most common idea is that the sun is burning gas - like a giant fireball in the sky. If this were true, the sun would have gone out long ago. So how is the sun actually fuelling itself? It is converting its own mass into energy. By combining protons (the nucleus of hydrogen) into helium, it squeezes some mass into energy - 4.3 billion kg per second. It is Einstein's famous E=mc^2 which gives us the quantitative relationship between mass and energy, where c is the speed of light.

Physics of contraptions meant to go faster than light.
Audible: http://bit.ly/AudibleVe
My video about the problem with Facebook: http://bit.ly/PwFB

Special thanks to MinutePhysics for visual effects and Prof. Geraint Lewis for revisions to earlier drafts of this video.

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

When air is compressed very quickly, it can reach high temperatures. In this demonstration we show how cotton wool can reach the point of auto-ignition by quick compression of air in the fire syringe.

In the mid 1800's scientists successfully passed an electric current through a vacuum in a glass tube. They saw a glow from the tube that seemed to emanate from the negatively charged plate called the cathode. Since scientists didn't know what the glow was they called it a cathode ray. There was debate over whether the cathode ray was a wave phenomenon like light or a stream of negatively charged particles. JJ Thomson effectively resolved the debate in 1897 by performing a clever experiment that determined the charge to mass ratio of the particles making up the cathode ray. He also showed that this same particle was in all different cathode materials so it must be a constituent common to all atoms. This changed our understanding of the atom from the previous billiard ball model to Thomson's plum pudding model of the atom.

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

Scientists have recently discovered nanodiamonds in the flames of ordinary candles. They are produced at a rate of about 1.5 million per second. Unfortunately they are also burned up at this rate and released into the atmosphere as carbon dioxide. Still this finding may prove useful in the ongoing search for economical ways to produce diamonds.

The strange thing about high jump is that the technique changed dramatically after 1968, when Dick Fosbury used his trademark flop to win the gold medal at the Olympics in Mexico City.
Previously the scissors and straddle had been the most common jumping technique, but after the introduction of safer landing matts, the new unorthodox Fosbury Flop became the jump of choice. There are good physical reasons for this - the style allows the jumper to pass over the bar while his or her centre of mass actually passes below the bar.

Huge thanks to Elly (Appchat http://bit.ly/NxAMlX ) for filming, editing, and music!

numberphile http://bit.ly/numberphile
efit30 http://bit.ly/O4CMme
appchat http://bit.ly/NxAMlX
erikaanear http://bit.ly/MdyUzQ
whoisjimmy http://bit.ly/LtFzpW
minutephysics http://bit.ly/Muh6CC
1veritasium http://bit.ly/MrupzL

New research shows chameleons actively tune nano-crystals to change their color.
For a 10-day free trial, check out http://lynda.com/veritasium
Chameleon research in Nature Communications: http://bit.ly/1FacHO2
"Photonic Crystals Cause Active Colour Change in Chameleons"

This research was carried out by Jérémie Teyssier, Suzanne V. Saenko, Dirk van der Marel & Michel C. Milinkovitch at the University of Geneva Department of Quantum Matter Physics and the Laboratory of Artificial and Natural Evolution (LANE)

Original videos of chameleons are here:
https://www.youtube.com/watch?v=YIRiCwHlUd8
https://www.youtube.com/watch?v=XdQvtP8EKrM
https://www.youtube.com/watch?v=YSH7EmXFMac
https://www.youtube.com/watch?v=egwueh6wj1E

Additional details available at: http://www.lanevol.org/LANE/ch....ameleon_colour_chang
For correspondence: Michel C. Milinkovitch, Laboratory of Artificial & Natural Evolution (LANE), Dept. of Genetics & Evolution, University of Geneva, Switzerland.

The melanin spreading out video is courtesy of Richard Wheeler:
https://www.youtube.com/watch?v=hL0USeWjTHQ
http://www.richardwheeler.net

Special thanks to:
Harry, Jo, Daniella and Raquel for helping me produce and film this video - it looks great thanks to you!