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
In a zero-g plane I experimented with flames and slinkies with surprising results.
Check out e-penser’s video: http://ve42.co/EPzeroG
Check out Physicsgirl’s video: http://ve42.co/PGzeroG
Special thanks to Patreon Supporters:
Tony Fadell, Donal Botkin, Nick Luchsinger, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen
The zero-g plane allows for a lot of experiments to be conducted without the expense of getting equipment into orbit. Apparently 80% of microgravity research can be performed in a zero-gravity plane, which is much cheaper than going to space. The flame from the lighter seemed much lazier in zero-g because without weight there is no buoyant force and therefore no convection. This makes the process of combustion more challenging because it’s difficult for oxygen to reach the fuel.
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.
I didn’t say it explicitly in the video, but in my view the Bayesian trap is interpreting events that happen repeatedly as events that happen inevitably. They may be inevitable OR they may simply be the outcome of a series of steps, which likely depend on our behaviour. Yet our expectation of a certain outcome often leads us to behave just as we always have which only ensures that outcome. To escape the Bayesian trap, we must be willing to experiment.
Special thanks to Patreon supporters:
Tony Fadell, Jeff Straathof, Donal Botkin, Zach Mueller, Ron Neal, Nathan Hansen, Saeed Alghamdi
Useful references:
The Signal and the Noise, Nate Silver
The Theory That Would Not Die: How Bayes’ Rule Cracked the Enigma Code, Hunted Down Russian Submarines, and Emerged Triumphant from Two Centuries of Controversy, by Sharon Bertsch McGrayne
Bayes’ theorem or rule (there are many different versions of the same concept) has fascinated me for a long time due to its uses both in mathematics and statistics, and to solve real world problems. Bayesian inference has been used to crack the Enigma Code and to filter spam email. Bayes has also been used to locate the wreckage from plane crashes deep beneath the sea.
The definitive answer about the direction water swirls in two hemispheres
Sync the videos yourself: http://toiletswirl.com
For the record Destin and I repeated the experiment 3-4 times each in each hemisphere and got the same results every time.
The idea that water going down a drain or flushed down a toilet swirls in opposite directions in the Northern and Southern Hemispheres has a long history. But few have ever done the experiment. Destin from Smarter Every Day and I performed identical experiments in the Northern and Southern hemispheres. What we found is the direction of water swirl in a toilet, sink, or bathtub is determined by other sources of angular momentum. However if the body of water is big enough, e.g. a kiddy pool, and left still for long enough (at least 24 hours), then the Coriolis effect is observable with water swirling counterclockwise in the Northern hemisphere and clockwise in the Southern hemisphere.
Gordon McGladdery did all of the sound design for the video. We used two songs from other artists (licensed of course). Derek split the first one up so it fades from video to video, and Gordon split the instruments up on the second one. There are violins on one video and percussion on the other for example. It’s really neat.
The neat earth animation at the beginning and the synchronizing timer was made by http://eisenfeuer.com/. He also made still images of the earth from the top and the bottom.
There was a study performed at MIT years ago (http://web.mit.edu/hml/ncfmf/09VOR.pdf) that explained the physics involved. We repeated some of these demonstrations, but on opposite sides of the globe…and in a way that can be easily understood.
This site is a great resource on the Coriolis effect and ways people have gotten it wrong: http://www.ems.psu.edu/~fraser/Bad/Ba…
Spinning magnets near copper sheets create levitation!
Try Audible free for 30 days: http://bit.ly/AudibleVe
Special thanks to Hyperloop One for showing me around.
Thanks to Patreon supporters:
Nathan Hansen, Donal Botkin, Tony Fadell, Saeed Alghamdi, Zach Mueller, Ron Neal, Perry cl, Bryan Baker
Support Veritasium on Patreon: http://bit.ly/VePatreon
Filmed by Raquel Nuno, Edited by Trevor Carlee
Obviously this “quadcopter” is a demonstration device, showing how moving magnets over a conducting surface can generate levitation. It has not been optimized to minimize losses or be an efficient mode of transport. I still think it’s pretty cool. I’m used to seeing light things levitated by induced currents but not a 100+ lb machine.
A head-vaporizing laser with a perfect wavelength detecting sub-proton space-time ripples.
Huge thanks to Prof Rana Adhikari and LIGO: http://ligo.org
Here’s how he felt when he learned about the first ever detection: https://youtu.be/ViMnGgn87dg
Thanks to Patreon supporters:
Nathan Hansen, Donal Botkin, Tony Fadell, Saeed Alghamdi, Zach Mueller, Ron Neal
Support Veritasium on Patreon: http://bit.ly/VePatreon
A lot of videos have covered the general overview of the discovery of gravitational waves, what they are, the history of the search, when they were found but I wanted to delve into the absurd science that made the detection possible.
When scientists want one megawatt of laser power, it’s not just for fun (though I’m sure it’s that too), it’s because the fluctuations in the number of photons is proportional to their square root, making more powerful beams less noisy (as a fraction of their total). The smoothest mirrors were created not for aesthetic joy but because when you’re trying to measure wiggles that are a fraction the width of a proton, a rough mirror surface simply won’t do.
Why we can’t seem to agree on what’s true when it’s easier than ever to check.
Videos like this are usually on 2Veritasium: http://bit.ly/2Veritasium
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This video was filmed at a meetup in Stockholm, Sweden on Dec. 9, 2016. Huge thanks to everyone who attended – I had a great time. Sorry to those of you I missed, especially Lund and Gothenburg.
Thanks to Patreon supporters (but this is a non-paid post):
Meshal Alshammari, Nathan Hansen, Bryan Baker, Donal Botkin, Tony Fadell, Saeed Alghamdi, Ron Neal
Silicone oil droplets provide a physical realization of pilot wave theories.
Check out Smarter Every Day: http://bit.ly/VeSmarter
Support Veritasium on Patreon: http://bit.ly/VePatreon
Thanks to Patreon supporters:
Nathan Hansen, Bryan Baker, Donal Botkin, Tony Fadell, Saeed Alghamdi
Thanks to Google Making and Science for helping me pursue my #sciencegoals. If you want to try this experiment, instructions are here: link.springer.com/article/10.1007/s12650-016-0383-5
The standard theory of quantum mechanics leaves a bit to be desired. As Richard Feynman put it, “I think I can safely say that no one understands quantum mechanics.” This is because observations of experiments have led us to a theory that contradicts common sense. The wave function contains all the information that is knowable about a particle, yet it can only be used to calculate probabilities of where a particle will likely turn up. It can’t give us an actual account of where the particle went or where it will be at some later time.
Some have suggested that this theory is incomplete. Maybe something is going on beneath the radar of standard quantum theory and somehow producing the appearance of randomness and uncertainty without actually being random or uncertain. Theories of this sort are called hidden variable theories because they propose entities that aren’t observable. One such theory is pilot wave theory, first proposed by de Broglie, but later developed by Bohm. The idea here is that a particle oscillates, creating a wave. It then interacts with the wave and this complex interaction determines its motion.
Experiments using silicone oil droplets on a vibrating bath provide a remarkable physical realization of pilot wave theories. They give us a physical picture of what the quantum world might look like if this is what’s going on – and this theory is still deterministic. The particle is never in two places at once and there is no randomness.
