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

Everyone is familiar with liquid water, ice and water vapour, but what are the differences between these three states of matter? Solids, liquids and vapours of the same substance differ in the motion of the molecules and the distance between them.

Animations courtesy of VisChem (Trade Mark), Copyright 1995, Roy Tasker. Thanks for all your help!

In April 2012, I was part of a team of scientists, teachers and students who travelled to Alaska to observe the Northern Lights or Aurora Borealis. Our mission was a unique one - to launch weather balloons up to 100,000 feet loaded with experiments, tracking devices and HD cameras. This is the result of our trip, produced for Catalyst on ABC1 http://www.abc.net.au/catalyst/

I used a nitrogen membrane and Stirling cryocooler to liquefy nitrogen out of the air. For this video I partnered with Starbucks to celebrate their Nitro Cold Brew. Order one here: https://starbucks.app.link/derekmuller

Making liquid nitrogen is hard - in fact up until 150 years ago scientists doubted whether it was even possible to liquefy nitrogen. In 1823, At the royal institution in London, Michael Faraday first produced liquid chlorine, kind of accidentally by putting it under high pressure. He similarly liquefied ammonia.

Borrowing a mixture from Thilorier in France, a combination of dry ice, snow and ether, he reached a temperature of -110C. By 1845 he used this mixture plus a hand pump to pressurize gases to liquefy all the known gases except six, which included oxygen and nitrogen. These became known as the “permanent” gases.

A French Physicist Aimé compressed oxygen and nitrogen in tanks and then lowered them into the ocean over 1.6km deep, where the pressure got up to 200 atmospheres. Still the gases didn’t liquefy.

Only at the end of 1877 were the first droplets of liquid oxygen and liquid nitrogen produced, by Cailletet in France. He first tried oxygen by compressing it up to 300 atmospheres, cooled to -30C, but that wasn't even enough to liquefy oxygen. But when he suddenly released the pressure, the expanding gas cooled, he estimated to -200C and he saw a mist and then droplets slide down the walls of his vessel.

It's amazing how far we've come in that now I can purchase a helium-based cryocooler. It compresses and expands the gas to absorb heat from the tip of the cold finger and eject it into the surroundings at ambient temperature.

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

Objects hang heavy side down, but what happens when you spin an asymmetrically weighted disk - well the heavy part actually rises to the top. Why is this?

1, 2, 3 A song about 'lectricity
because it powers our lives
makes it possible for us to thrive

because it powers our lives
makes it possible for us to thrive

Oh, 4, 5, 6, volts of potential difference
makes electrons go round
if the circuit is complete and sound

Circuit's closed
Voltage There
Current Flows
Power Everywhere

We use AC,
in factories
and homes because we can transform it
High voltage
transmits with lower loss
but low voltage is best for safety
I said what is electricity?

Well, so 1,2,3 a song about 'lectricty
because it powers our lives
makes it possible for us to thrive

because it powers our lives
makes it possible for us to thrive

Oh, 4,5,6 volts of potential difference
makes electrons go round if the circuit is complete and sound

Heat makes steam
turns turbines
and a magnet in
coils of wires

We use AC,
in factories
and homes because we can transform it
High voltage
transmits with lower loss
but low voltage is best for safety
I said what is electricity?

Oh yeah, Oh yeah, C'mon!
How'd it be
no energy
of the electrical persuasion
I know we'd
have no computers
no internet or mobile phones yeah
Powers the world
Makes the world
We need electricity yeah

How lift actually works: http://www.youtube.com/watch?v=aFO4PBolwFg
More with Canadian Olympian Hunter Lowden: http://www.youtube.com/watch?v=6YVOPUkbu6g

How does a sailboat work? The standard idea is that the wind pushes the sails from behind, causing the boat to move forward. Although this technique is used at times, it is not the most efficient way to sail a boat (and it means the boat can never go faster than the wind). Lift is the key mechanism driving a boat forwards. As air flows over the sails, it moves faster over the outer side, creating lower pressure than on the inner side. This produces a force which is mostly to the side and a bit forwards. Lift on the centerboard pushes to the opposite side, cancelling the sideways force and adding a forward component of force to the boat.

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

Scientists have combined ultrasound, viruses and synthetic drugs to control regions of the brain.
Check out Skillshare: https://skl.sh/veritasium (first 500 get 2 months free)

Special thanks to Prof. Mikhail Shapiro and Dr. Jerzy Szablowski:
http://shapirolab.caltech.edu

Human brains are complicated - the most complicated thing in the known universe, many people say. So far we understand little - just that certain regions of the brain appear to be involved in certain activities and certain disorders. In extreme cases this has led to the practice of removing sections of the brain, or using electrodes or optical fibers to control activation rates. What is unique about this approach is it offers a way to turn on and off specific brain regions without invasive surgery. It has promise because it combines existing technologies: micro-bubbles, ultrasound, synthetic viruses, and synthetic drugs to achieve this goal.

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

Animations and editing by Alan Chamberlain

Music from http://epidemicsound.com "Experimental1"

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

We also made a video about laser cooling! http://bit.ly/PhysGirl
Check out Audible: http://bit.ly/AudibleVe
Check out Beyond Slow Motion: http://bit.ly/VeBeyondSlowMo
More on this topic: http://wke.lt/w/s/ef3eV

Special thanks to Laser Away in Santa Monica for helping make this happen - your staff was awesome! http://bit.ly/VeLaserAway

Research and filming by Raquel Nuno and Aaron White.

Subscribe to Veritasium - it's FREE! http://bit.ly/YSWpWm
Check out other unanswered science questions: http://youtu.be/UFydagCS9fg

The universe is huge. That means two things: 1. there is probably life elsewhere, 2. It is likely too far away to have reached us.

Fast, Furious & Funny - http://www.youtube.com/fastfuriousand... (http://www.youtube.com/watch?v=YWxub2...)

The Brain Scoop - http://www.youtube.com/thebrainscoop (http://youtu.be/mNuu0y6ZmAs)

ASAPScience - http://www.youtube.com/AsapSCIENCE (http://www.youtube.com/watch?v=wgxJhp...)

The Royal Institute of Great Britain - http://www.youtube.com/TheRoyalInstit... (http://www.youtube.com/watch?v=gm02Oi...)

PBS Idea Channel - http://www.youtube.com/pbsideachannel (http://www.youtube.com/watch?v=TbNymw...)

The Spangler Effect - http://www.youtube.com/TheSpanglerEffect (http://www.youtube.com/watch?v=4fQ4uB...)

Minute Physics - http://www.youtube.com/minutephysics (http://www.youtube.com/watch?v=2yHDeK...)

Head Squeeze - http://www.youtube.com/HeadsqueezeTV (http://www.youtube.com/watch?v=UPBJX1...)

Vsauce - http://www.youtube.com/Vsauce (http://www.youtube.com/watch?v=L45Q1_...)

Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space. ~Douglas Adams

Thanks to Dr. Simon O'Toole for talking exoplanets with me! We also discussed the Drake equation but there wasn't really room for it.

Camera by Charles Clement

Music by Kevin McLeod (incompetech.com) Mirage, Scissors

Negative Pressure Exists! http://bit.ly/TFilQ8
Vsauce's Space Straw: http://bit.ly/XubIm3
Smarter Every Day's Prince Rupert's Drop: http://bit.ly/10VQBGW
ViHart's Optimal Potatoes: http://bit.ly/14egJoe

Thanks to Questacon for filming! Check out their slow-mo playlist: http://bit.ly/ZoWFGR
Science Alert brings science to your news feed: http://on.fb.me/14ehuxA

Music by Kevin Mcleod (http://incompetech.com): Pale Rider & The Cannery

It takes the moon about 27 days to orbit the Earth. What makes it go round? It is the gravitational attraction of the Earth on the moon. Due to the moon's velocity, the Earth keeps pulling the moon towards it without the moon actually getting closer to the Earth. This is similar to how satellites orbit the Earth.

Tiny robots activated by magnetic fields may be used in future biomedical procedures. Start listening to Audible with a 30-day trial and your first audiobook, plus two Audible Originals free when you go to http://audible.com/veritasium or text veritasium to 500500

Huge thanks to:
Dr. Eric Diller, Assistant Professor of Mechanical Engineering at the University of Toronto
http://microrobotics.mie.utoronto.ca

Research Referenced in this video:

T. Xu, J. Zhang, M. Salehizadeh, O. Onaizah and E. Diller, Millimeter-scale flexible robots with programmable three-dimensional magnetization and motions. Science Robotics. 4, eaav4494 (2019).
http://robotics.sciencemag.org..../lookup/doi/10.1126/

H. Xie, M. Sun, X. Fan, Z. Lin, W. Chen, L. Wang, L. Dong, and Q. He, Reconfigurable magnetic microrobot swarm: Multimode transformation, locomotion, and manipulation. Science Robotics. 4, eaav8006 (2019).
http://robotics.sciencemag.org..../lookup/doi/10.1126/

G. Hwang, A. J. Paula, E. E. Hunter, Y. Liu, A. Babeer, B. Karabucak, K Stebe, V. Kumar, E. Steager, and H. Koo, Catalytic antimicrobial robots for biofilm eradication. Science Robotics. 4, eeaw2388 (2019).
http://robotics.sciencemag.org..../lookup/doi/10.1126/

Special thanks to Patreon supporters:
Donal Botkin, Michael Krugman, Ron Neal, Stan Presolski, Terrance Shepherd, Penward Rhyme

Music by Kevin MacLeod http://incompetech.com "Marty Gots a Plan" "March of the Spoons"

In Queenstown, New Zealand, I jumped off the Kawarau Bridge - the site of the first bungy jump. It was a thrilling experience, preceded by a terrifying, gut-wrenching half hour wait. All in all an awesome adventure, even if the woman fitting my harness didn't know the first thing about the acceleration of free-falling bodies.

Starring: Christie Wykes as Chlorine, Carbon, and Sodium
Director of Photography: Sean McCallum
Gravity (John Mayer Cover) http://www.youtube.com/watch?v=u7KpH9_I2Dw
I'm Atoms (Jason Mraz Cover) http://www.youtube.com/watch?v=DBjZz0iQrzI
Electricity (Jet Cover) http://www.youtube.com/watch?v=cY-kiddvAg0
Experiments A Cappella http://www.youtube.com/watch?v=lRbI_vPyOnc

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.

Scientific research has shown that heterosexual males and females find members of the opposite sex more attractive when they wear the colour red. This is a subconscious preference that seems to have some evolutionary basis. We attempted to replicate these findings in Sydney but our methods were much less controlled and the results achieved were not statistically significant.

I'm going to London! And I'm leading a team of YouTubers. For the next few weeks we will all be doing videos themed around the Olympics so I'm tackling the science of sport and science in and around London.

The Team!
HOWRIDICULOUS: http://bit.ly/LtFzpW
APPCHAT: http://bit.ly/NxAMlX
ERIKAANEAR: http://bit.ly/MdyUzQ
MINUTEPHYSICS: http://bit.ly/Muh6CC
EFIT30: http://bit.ly/O4CMme

2VERITASIUM http://youtube.com/2veritasium

Music by Alankeys86 and Kevin McLeod (Incompetech.com)

For the London 2012 Summer Olympics creators from all over the world are taking over YouTube with the most awesome Olympics videos ever. Go to YouTube.com/CreatorHub to see all the amazing gold medal videos.