Top Vídeos

10 Facts About Great White Sharks

Veritasium
13 vistas · 6 años hace

Remarkably little is known about great white sharks, but they are similar to humans in a lot of ways - they give birth to live young, maintain a higher body temperature than their surroundings and they are apex predators. There are also many misconceptions about these sharks: people think they don't get cancer and that they reside mainly in shallow waters near beaches. In this video I summarize some of the most interesting things I learned about sharks on my cage diving adventure.

Special thanks to Rodney Fox Shark Expeditions for making this trip possible: http://bit.ly/rodneyfox

Thanks also to Tourism South Australia for facilitating the trip: http://bit.ly/1aq9MgV

Chris Cassella or C² as he is known after this trip was a shark spotter extraordinaire. He also took some of the best shark footage in this video. It was his idea to go on this expedition, which was definitely a once in a lifetime experience, so I am in his debt. Chris, I look forward to going on more great adventures with you. Check out Chris's facebook page ScienceAlert http://on.fb.me/18nhyLp

Water on the Moon?

Veritasium
13 vistas · 6 años hace

NEW CHANNEL! http://youtube.com/sciencium

For a long time we thought the Moon was completely dry, but it turns out there are actually three sources of lunar water.
Thanks to Google Making and Science for supporting the new channel! http://youtube.com/makingscience

Thanks to Patreon supporters:
Nathan Hansen, Donal Botkin, Tony Fadell, Zach Mueller, Ron Neal

Support Veritasium on Patreon: http://bit.ly/VePatreon

References:
Great history of water on the moon: https://arxiv.org/pdf/1205.5597.pdf

Filmed by Raquel Nuno

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

The Science Behind the Butterfly Effect

Veritasium
13 vistas · 6 años hace

Chaos theory means deterministic systems can be unpredictable. Thanks to LastPass for sponsoring this video. Click here to start using LastPass: https://ve42.co/VeLP
Animations by Prof. Robert Ghrist: https://ve42.co/Ghrist

Want to know more about chaos theory and non-linear dynamical systems? Check out: https://ve42.co/chaos-math

Butterfly footage courtesy of Phil Torres and The Jungle Diaries: https://ve42.co/monarch
Solar system, 3-body and printout animations by Jonny Hyman
Some animations made with Universe Sandbox: https://universesandbox.com/
Special thanks to Prof. Mason Porter at UCLA who I interviewed for this video.

I have long wanted to make a video about chaos, ever since reading James Gleick's fantastic book, Chaos. I hope this video gives an idea of phase space - a picture of dynamical systems in which each point completely represents the state of the system. For a pendulum, phase space is only 2-dimensional and you can get orbits (in the case of an undamped pendulum) or an inward spiral (in the case of a pendulum with friction). For the Lorenz equations we need three dimensions to show the phase space. The attractor you find for these equations is said to be strange and chaotic because there is no loop, only infinite curves that never intersect. This explains why the motion is so unpredictable - two different initial conditions that are very close together can end up arbitrarily far apart.

Music from https://epidemicsound.com "The Longest Rest" "A Sound Foundation" "Seaweed"

Gravitational Wave Discovery! Evidence of Cosmic Inflation

Veritasium
13 vistas · 6 años hace

Baby photos of our universe show huge early growth spurt!
Check out Audible: http://bit.ly/AudibleVe
Regression to the Mean: http://bit.ly/1lgZQAQ

Some clarifications:
- The lengthening of wavelengths is not strictly due to stretching by the expanding universe but by the way the photons were emitted and absorbed in different frames of reference.
- The effects of gravitational waves have been observed in the decaying orbital periods of some binary star systems, however detectors built to measure gravitational waves stretching and squeezing matter on Earth have not as yet detected them.
- In the video I sometimes use the term Big Bang to refer to the beginning of time as we know it. The Big Bang actually refers to the whole process from the formation of our universe, through inflation, to the expanding mass of plasma in the early universe (not just the first instant).
- Quantum gravity is by no means established by this observation but it is suggestive that General Relativity and Quantum Mechanics are working together here.

Thank you to Professor Geraint Lewis and Henry Reich for comments on earlier drafts of this video (even if I haven't accepted all of your corrections).

NASA 2020: A Year of Action

admin
13 vistas · 6 años hace

This year, NASA is building momentum across the agency and across every mission. This is a year of action. With each milestone, NASA is preparing to go farther than ever before.
NASA is going to the Moon and on to Mars, in a measured, sustainable way. Working with U.S. companies and international partners, NASA will push the boundaries of human exploration forward to the Moon. NASA is working to establish a permanent human presence on the Moon within the next decade to uncover new scientific discoveries and lay the foundation for private companies to build a lunar economy. We inspire generations and change the course of history as we realize the next great scientific, economic and technical achievements in space.

This video is available for download from NASA's Image and Video Library: https://images.nasa.gov/detail....s-NHQ_2020_0210_NASA

NASA Live: Official Stream of NASA TV's Media Channel

admin
13 vistas · 6 años hace

Direct from America's space program to YouTube, watch NASA TV live streaming here to get the latest from our exploration of the universe and learn how we discover our home planet.

NASA TV airs a variety of regularly scheduled, pre-recorded educational and public relations programming 24 hours a day on its various channels. The network also provides an array of live programming, such as 24-hour coverage of missions, events (spacewalks, media interviews, educational broadcasts), press conferences and rocket launches.

In the United States, NASA Television's Public and Media channels are MPEG-2 digital C-band signals carried by QPSK/DVB-S modulation on satellite AMC-3, transponder 15C, at 87 degrees west longitude. Downlink frequency is 4000 MHz, horizontal polarization, with a data rate of 38.86 Mhz, symbol rate of 28.1115 Ms/s, and ¾ FEC. A Digital Video Broadcast (DVB) compliant Integrated Receiver Decoder (IRD) is needed for reception.