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/

We talk about all the potentially challenging situations autonomous cars could get into but not about how human drivers are not very good. Tens of thousands die on the roads every year in collisions, most of which could be prevented by autonomous vehicles.
Sponsored by BMW

I wanted to make a video about autonomous cars for some time but I hadn't had the opportunity. The self-driving technology is already at a state where it can save lives if only it were more widely implemented.

Links to original clips:
TED-Ed https://www.youtube.com/watch?v=ixIoDYVfKA0
BBC Newsnight: https://www.youtube.com/watch?v=FypPSJfCRFk&t=172s

Music from http://www.epidemicsound.com "Ambient Electronic Groove," "Pet Animals 2," "The Long Ride."
Filmed by Raquel Nuno
Edited by Trevor Carlee

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

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!

Or almost any garage - it's particularly good with fixed code gates and garages. Samy proposes other weaknesses with rolling codes.
This video was sponsored by LastPass: http://bit.ly/2oscAe9

I don't condone malicious hacking of gates, garages or other property. The point of this video was to discuss how it could be done using fairly basic technology like this toy that was originally intended as an instant messaging device. I learned a lot in making this video about how codes are sent and received, how they are encrypted or not encrypted. I found out how hard it is to execute in practice something which in principle doesn't seem that difficult.

Special thanks to Samy! His original videos on using the IM ME to open radio frequency garages and gates can be found here: https://www.youtube.com/user/s4myk
He's got a really cool channel so be sure to subscribe if you're interested in this stuff.

Music from http://epidemicsound.com "Critical thinking 2" "I think I was there" "Magnified X 3"

And music by Kevin MacLeod http://incompetech.com "Marty Gots a Plan"

Newton's Law of Universal Gravitation can be summarized as "all mass attracts all other mass." But if this is true, why don't we notice the gravitational force of attraction between everyday objects? The reason is because the gravitational force is quite weak.

Students at UCF are designing an inexpensive 3D printed arm for kids.
To find out more and to get involved, check out: http://office.tumblr.com

Big thanks to Microsoft and the Collective Project for introducing me to Albert and his amazing team. They are continuing to help people around the world one hand at a time and they could use your help.
Learn more and see how you can get involved by checking out The Collective Project on Tumblr, follow @MSONeNote on Twitter or head over to http://Onenote.com/collectiveproject

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.

Veritasium second channel: http://bit.ly/2Veritasium
Rodney Fox Shark Attack Story: http://bit.ly/1frAwlI
Check out Audible: http://bit.ly/AudibleVe

For this video I went off the coast of South Australia to an island frequented by great white sharks. Here they hunt seals and fish. I've never been scuba diving before but I got into a cage and filmed the sharks under water. It was an incredible experience. Then we came back on the surface to tag the sharks.

How can you Yo-Yo without the string attached?
Check out Audible: http://bit.ly/AudibleVe
For more Ben Conde: http://bit.ly/VeBenConde
For Beyond Slow Motion: http://bit.ly/VeBeyondSlowMo

For more on yo-yos check out: http://bit.ly/290wR3a

How to yo-yo without a string attached... So many crazy tricks and the science that makes it possible.

Edited and animated by Daniel Joseph Files

I have the photic sneeze reflex so I sneeze when I look at bright light.
Check out 23andMe: http://ve42.co/23andme
*So technically the single nucleotide swap (C instead of T) is not actually in a gene per se but in an intergenic region on chromosome 2. It's also not clear exactly how this affects physiology or causes the sun sneeze but there is correlative evidence that every copy of this single nucleotide polymorphism (SNP) is associated with a 1.3x increase in likelihood of having the photic sneeze reflex.

I have wanted to make a video about sun-sneezing for a long time. It is something I've experienced my whole life. When I go from a dark room indoors into full sunlight I invariably sneeze. I thought everyone did it. So my original question was why do people sneeze when they see bright light? That led me to consider what possible evolutionary advantages there could be to sneezing in sunlight. The obvious advantage to me is that sunlight kills pathogens of which there may be many in your snot or mucus. So sneezing in sunshine is a much better idea than sneezing inside a dark, damp cave where you may be living.

For more info, check out:
Web-Based, Participant-Driven Studies Yield Novel Genetic Associations for Common Traits
http://journals.plos.org/plosg....enetics/article?id=1

Filmed by Raquel Nuno

If you spin a raw egg and then stop it, it will start spinning again without you having to touch it. A boiled egg, on the other hand, stops and stays stopped. Why is this? Well a raw egg contains a yolk that moves inside the egg independently of the shell. If you stop the shell, the yolk inside continues to move due to its inertia and it therefore gets the egg spinning again.

The Nobel Prize for physics in 2011 was awarded to Brian Schmidt, Adam Riess, and Saul Perlmutter for discovering that the universe is expanding at an accelerating rate. This finding was completely unexpected because it was thought that gravity should slow the expansion of the cosmos. The best current explanation of why the universe is accelerating is that there is some energy tied to empty space which pushes matter apart. This 'Dark Energy' makes up 73% of the universe but is very difficult to detect. Hopefully a better understanding of it will lead to a unification of our theories of gravitation and quantum mechanics.

Images courtesy of NASA - NASAimages.org

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

A bisected grape in the microwave makes plasma. But how does it work? A grape is the right size and refractive index to trap microwaves inside it. When you place two (or two halves) close together the fields interact with each other creating a maximum of electromagnetic energy where they touch. This creates heating, sparks, and plasma, which is further fed with energy directly by the microwaves.

Huge thanks to Hamza Khattak, Prof. Pablo Bianucci and Prof. Aaron Slepkov (unavailable for the call) for chatting to me and helping me understand the physics of this cool phenomenon.

Linking plasma formation in grapes to microwave resonances of aqueous dimers
https://www.pnas.org/cgi/doi/1....0.1073/pnas.18183501

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

Thanks also to Steve Bosi, my original plasma collaborator.

Animations by Alan Chamberlain

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

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

People have a lot of different ideas about what gravity is: a downward force that stops you from flying off into space, an attraction smaller objects experience towards larger objects, or a mutual attraction between all masses. It is the last of these ideas that best reflects a scientific conception of gravity.

Grant Thompson - the King of Random - teaches me how to start a fire with a Sandwich bag. And we tried to melt glass in my backyard: https://goo.gl/zb0uE0
Check out his channel: http://ve42.co/KoR

The intensity of sunlight on Earth is about 1300 Watts per square meter. When you focus the sun's rays using a magnifying glass (or in this case sphere of water) you can increase the intensity roughly ten thousand fold. This increases the temperature of wood to its autoignition point starting the reaction with oxygen in the atmosphere. By protecting the hot embers and adding more energy and fuel, you can get these hot coals to start a roaring fire.

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

What was the procedure to launch a nuclear missile?
Uranium premieres: July 28 & 29 on PBS at 10pm ET/ 9pm Central
France and Germany: July 31 at 10pm on ZDF/arte
Norway: August 5 & 6 at 21:30 on NRK2
Australia: August 9, 16, 23 at 8:30pm on SBS
Sweden: TBD
Middle East: TBD

For more information on other screenings go to
https://www.facebook.com/uraniumtwistingthedragon
www.genepoolproductions.com

A big thank you to The Titan Missile Museum, Yvonne and Chuck.
http://www.titanmissilemuseum.org/

Space footage courtesy of NASA

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.