Mohamad Jebara loves mathematics — but he’s concerned that too many students grow up thinking that this beautiful, rewarding subject is difficult and boring. His company is experimenting with a bold idea: paying students for completing weekly math homework. He explores the ethics of this model and how it’s helping students — and why learning math is crucial in the era of fake news.
The TED Talks channel features the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design — plus science, business, global issues, the arts and more.
This evidence seems to suggest that the dark matter is particles that are less than four times the mass of a proton and are moving at non-relativistic speeds. This is consistent with dark matter particles being so-called WIMPs: https://en.wikipedia.org/wiki/Weakly_interacting_massive_particles.
We did something a little different in this episode and answered questions from you, our viewers. If you have a questions about the universe, past videos, or life as a scientist, leave a comment below!
How can you train yourself to be a quantum detector? Quantum interactions happen at impossibly small scales. But the life-size effects are all around you. You can detect quantum mechanics all over — if you know how to look for it.
ADVANCED SCIENTIFIC NOTE: Quantum mechanics would be much more obvious if we had very sensitive eyes. If your eyes identified each photon individually, you would see them land as described in the video, and only build up to this wave pattern. The pattern that we see can be explained classically by waves, it is *ultimately* a quantum phenomenon. The only reason it’s hard to tell is because our light detectors (eyes) aren’t quite sensitive enough.
NOVA has teamed up with Cook’s Illustrated to cook up a recipe for stars and black holes – a culinary “course” on how the most mysterious objects in the universe are created.
James Bissonette, James Gill, Cas Eliëns, Jeremy Banks, Thomas J Miller Jr MD, Jaclyn Cauley, David F Watson, Jay Edwards, Tianyu Ge, Michael Cao, Caron Hideg, Andrea Di Biagio, Andrey Chursin, Christopher Anthony, Richard Comish, Stephen W. Carson, JoJo Chehebar, Mark Govea, John Buchan, Donal Botkin, Bob Kunz
ESA is taking advantage of Novespace’s latest ‘Zero-G’ aircraft to perform a number of experiments in microgravity. Twelve experiments – which include six by professional scientists and six by students as part of ESA’s Fly Your Thesis programme – took to the skies for three series of 31 parabolas off the coast of France. Conditions of microgravity, or weightlessness, are unique for research ranging from fundamental physics, testing Einstein’s weak equivalence principle, to psychology, neuroscience and the deployment of a balloon that may one day make measurements while falling through Mars’ atmosphere.
Christina, a physicist from Denmark, shares her experience as a Young Graduate Trainee. In ESA she is working in the Education Office, and in this video she talks about a project she is part of there, the AstroPi challenge, and what motivates her to work on educational material in the European Space Agency.
SCIENTIFIC NOTES:
* The relationship between information and energy comes from Landauer’s Principle, which connects the erasure of information and energy. But, more generally changes in information (e.g. recording information) are related to changes in energy. I will talk more about this in a future episode about the physics of memory, and why you will forget everything you ever knew! https://en.wikipedia.org/wiki/Landauer%27s_principle
* The numbers calculated in this video give a lower limit on the energy to record a particular amount of information, but to create a more permanent storage of information would require more energy.
* Retina display resolution, as it’s name implies, is similar to the eye’s resolution.
So we’ve talked a lot in this series about how computers fetch and display data, but how do they make decisions on this data? From spam filters and self-driving cars, to cutting edge medical diagnosis and real-time language translation, there has been an increasing need for our computers to learn from data and apply that knowledge to make predictions and decisions. This is the heart of machine learning which sits inside the more ambitious goal of artificial intelligence. We may be a long way from self-aware computers that think just like us, but with advancements in deep learning and artificial neural networks our computers are becoming more powerful than ever.
What makes a brain or machine conscious? Will robots become more conscious than we are? One theory, which can actually calculate consciousness, is beginning to provide some answers.
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Neuroscientist Greg Gage takes sophisticated equipment used to study the brain out of graduate-level labs and brings them to middle- and high-school classrooms (and, sometimes, to the TED stage.) Prepare to be amazed as he hooks up the Mimosa pudica, a plant whose leaves close when touched, and the Venus flytrap to an EKG to show us how plants use electrical signals to convey information, prompt movement and even count.
The TED Talks channel features the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design — plus science, business, global issues, the arts and more.
Paxi przybywa na Planetę Ziemia. Razem z nim dowiedz się więcej o obiegu wody w przyrodzie. W tym filmie, przeznaczonym dla dzieci w wieku 6-12 lat, Paxi tłumaczy jak działa obieg wody.
4-year old Sophia talks and plays with Buddy’s Flashcards (MyBuddy.ai) to learn numbers and discover animals. English is Sophia’s second language, and Buddy helps her to learn new words and improve her pronunciation. She picks it up right away.
Sign up at MyBuddy.ai to be notified when the App will be available on the App Store.
Scientific notes:
Stellar mass black holes vs. supermassive black holes
* Stellar mass black holes form from the collapse of massive stars at the ends of their lives, so they have roughly the same mass as a star. Supermassive black holes are physically identical to their smaller counterparts, except they are 10 thousand to a billion times the size of the sun. However, their formation is more of a mystery. They may form from the merging of smaller black holes. http://astronomy.swin.edu.au/cosmos/S/Supermassive+Black+Hole
Supermassive black holes at the center of galaxies
* Almost every large galaxy has a supermassive black hole at its center, but researchers are not yet sure (https://jila.colorado.edu/research/astrophysics/black-holes-galaxies) why that’s the case, how they originate, and what their role is in the creation and evolution of galaxies.
Why are stars different colors?
* The color of a star depends on its temperature (http://www.atnf.csiro.au/outreach/education/senior/astrophysics/photometry_colour.html). The hotter a star, the higher energy its light will be. Higher energy/temperature corresponds with the blue end of the visible spectrum and lower energy/temperature corresponds with the red end.
How does dark matter make stars spin faster?
* In the 1960s, astronomers Vera Rubin and Kent Ford noticed that stars at the edges of galaxies were moving just as fast as stars at the center, which surprised them: it appeared that the force of gravity causing stars to orbit the center of the galaxy was not weakening over distance. Their observation implied that something else, distributed throughout the galaxy, was exerting a gravitation pull. We now know that that “something else,” now named dark matter, accounts for about 85% of the matter in the universe. (It existence was inferred in the 1930s, when the astronomer Fritz Zwicky(http://www2.astro.psu.edu/users/rbc/a1/week_10.html) noticed that galaxies in clusters were moving faster than they should.)
Size of the universe
* The universe is only 13.8 billion years old, but has a radius of about 46 billion light-years. If nothing can travel faster than the speed of light, how can that be? The expansion of the universe, driven by dark energy, is causing distances between objects to grow. Note that it is not moving those objects apart; rather, it is increasing the amount of space between them. https://phys.org/news/2015-10-big-universe.html
Cosmic webs
* Galaxies are not distributed randomly (http://skyserver.sdss.org/dr1/en/astro/structures/structures.asp) in space; instead, clusters of galaxies form web-like patterns. These webs consist of filaments, where dark matter and ordinary (baryonic) matter are concentrated, and voids, where galaxies are scarce. Researchers believe that these large-scale structures grew out of minor fluctuations in density at the beginning of the universe.
Composition of the early universe
* Moments after the Big Bang, the universe formed the nuclei for what would be come the universe’s hydrogen and helium atoms, with one helium nucleus for every 10 or 11 hydrogen (http://umich.edu/~gs265/bigbang.htm). When the first stars formed, there were no heavier elements — those elements formed inside stars.
String Theory Landscape
* The String Theory Landscape is a theory that the universe we live in is one of many universes. It attempts to explain how certain constants of nature seem “fine-tuned” for life, which contradicts the anthropic principle, or the notion that we humans hold a special place in the universe. https://www.scientificamerican.com/article/multiverse-the-case-for-parallel-universe/%0A
Disintegration of the universe
* In the future Degenerate Era of the universe, as space-time expands and stars burn up, all of the matter in stars will be consumed by black holes. But even black holes are not forever. Stephen Hawking theorized that black holes will slowly radiate away their mass in what is now called Hawking radiation until they too dissipate away. http://www.nytimes.com/books/first/a/adams-universe.html
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MEDIA CREDITS:
Music provided by APM
Sound effects: Freesound.org
Additional Animations:
– Galaxy within Universe: Edgeworx;
– Stars at center of Milky Way – NASA/NCSA University of Illinois Visualization by Frank Summers, Space Telescope Science Institute, Simulation by Martin White and Lars Hernquist, Harvard University
What if everything in the universe came to your doorstep…in a box?! What The Physics is BACK! Future episodes will explore the universe—but first, let’s unbox it.
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SCIENTIFIC NOTES:
Explosive young stars
* The average lifetime of a star is about 10 billion years, but the bigger the star, the shorter its life. One rare type of star, called a hypergiant, can be tens, hundreds, or even a thousand times the mass of our sun. These stars burn out and explode into supernovae in just a few million years. http://www.guide-to-the-universe.com/hypergiant-star.html
Black holes
* Black holes form from the collapse of a massive star at the end of its life, but this only happens in stars about three times as massive as the sun. http://burro.case.edu/Academics/Astr201/EndofSun.pdf
How big is the universe?
* Probably infinite. No one knows the size of the universe for sure, and we may never know, but the latest thinking is that it probably goes on forever. https://map.gsfc.nasa.gov/universe/uni_shape.html
Standard cosmological model
* According to the standard cosmological model, the universe started with a big bang, underwent rapid inflation within the first fraction of a second, and continues to expand, driven by a vacuum energy called dark energy. All of the structure we see in the universe has come from interactions between dark energy and dark matter (which accounts for about 85% of the universe’s matter). This model describes and predicts many phenomena in the universe but is not perfect. https://physics.aps.org/articles/v8/108
False vacuum model
* The false vacuum model is a real, albeit unlikely theory. All the fundamental forces of nature have corresponding fields (e.g., gravitational fields, magnetic fields, etc.), and we generally believe that the universe is at rest in a global minimum of the potentials of those fields. But if we are instead at rest in a local minimum, or a “false vacuum,” the universe could potentially be nudged, catastrophically, into a lower minimum.
Recycling stars into life
* Before the first stars, the universe was all hydrogen and helium. All heavier elements, including the building blocks of life, were forged in stars.
Dark matter and dark energy
* Only 5% of the universe is made up of matter we can see. The “missing mass” later dubbed dark matter was first noticed in the 1930s; dark energy was discovered in the 1990s. In both cases, their existence was inferred by their effect on objects they interact with. However, they are still not directly observable, so nobody knows yet what they are made of.
Leftover light from the Big Bang
* The theory of the Big Bang predicted the existence of cool radiation pervading the universe, left over from its beginning. In an accidental discovery, two New Jersey scientists discovered the cosmic microwave background, a nearly uniform bath of radiation throughout the universe at a temperature of about 3 Kelvin, or -454 degrees Fahrenheit.
Gravitational waves
* Albert Einstein predicted the existence of gravitational waves in his theory of general relativity in 1916. According to his theory, the acceleration of massive objects, like black holes, should send ripples through space-time at the speed of light. A century after his prediction, two merging black holes sent a ripple through space-time that was detected on Earth as a signal that stretched the 4-kilometer arms of a detector by less than 1/1,000 the width of a proton.
Cosmic dust
* Cosmic dust is cast off from stars at the end of their lives and hovers in galaxies as clouds. These clouds of dust absorb ultraviolet and visible light, obscuring much of what lies behind them. This makes it notoriously difficult to study things like the dusty center of our galaxy.
The observable universe
* The universe is 13.8 billion years old. Since the distance we can observe is limited by the time it takes light to travel to Earth, we can only ever observe a fraction of the universe: an expanding sphere around us that is now about 46 billion years in radius. However, the universe is much larger than what we can observe.
CREDITS:
Host, Writer, Producer: Greg Kestin
Animation & Compositing: Danielle Gustitus
Contributing Writers: Lissy Herman, HCSUCS
Filming, Writing, & Editing Contributions from:
Samia Bouzid and David Goodliffe
Creation of Sad Star Image: Drew Ganon
Special thanks:
Julia Cort
Lauren Aguirre
Ari Daniel
Anna Rothschild
Allison Eck
Fernando Becerra
And the entire NOVA team
Recently, we partnered with Children’s Hospital Los Angeles (CHLA) to build a VR simulation that places medical students and staff in rare yet high-risk pediatric trauma situations where split-second decisions determine whether a patient lives or dies. Thanks to the immersive power of VR, we can replicate these training scenarios in true-to-life fashion, complete with paramedics rattling off symptoms, nurses and techs urging you to make a decision, and distraught parents praying for their child’s survival.
These visceral, interactive exercises up the stakes compared to traditional educational tools like non-VR simulations and mannequins. Powered by AiSolve and brought to life by the Hollywood VFX magic of BioflightVR, these virtual scenarios based on actual CHLA case studies let doctors and students practice and learn in realistic workplace conditions. Not only does this new innovation stand to significantly reduce the time and cost associated with mannequin-based training, it also better prepares people to respond in the real world.
This video, part of a series of ESA teaching resources called ‘Teach with space’, demonstrates an experiment that can be performed by students to observe everyday objects in infrared light. This is achieved by modifying a cheap webcam to allow it to block visible light and receive infrared light.
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