The Coriolis effect says that anytime you’re rotating—whether it’s on a playground toy or your home planet—objects moving in straight lines will appear to curve. This bizarre phenomenon affects many things, from the paths of missiles to the formation of hurricanes.
You may have heard that the Coriolis effect makes water in the bathtub spiral down the drain in a certain way, or that it determines the way that a toilet flushes. That’s actually wrong.
Although, as you may have noticed while tracking a hurricane on the news, storms in the Northern Hemisphere spin counterclockwise, while those in the Southern Hemisphere spin clockwise. Why do storms spin in different directions depending on their location? And why do they spin in the first place? The answer is the Coriolis effect.
You’ve probably seen atoms like this emoji ⚛ everywhere from science textbooks to the logo for The Big Bang Theory. But what does an atom really look like? The truth is much stranger.
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What if the Earth were swallowed by a black hole? Would humanity’s legacy be gone forever? Or could you somehow get back that information from behind the event horizon?
There are three possible answers to this question…but they all break physics as we know it!
Have you ever wondered what it would be like to fall into a black hole? Take a 360° adventure to find out!
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#1. Speed of sound: Unlike light, sound needs a medium to travel through, and its speed depends on characteristics of that medium like density and temperature. In the extreme environment of a neutron star’s core, sound can travel extremely fast. But knowing that sound can’t surpass the speed of light, physicists can narrow down their models of neutron stars to include only those where “extremely fast” is less than light speed.
#3. Relativity rainbows: A team at MIT created a game called “A Slower Speed of Light” that lets you see the world as you would at near-light speeds. Their trailer: https://www.youtube.com/watch?v=uu7jA8EHi_0
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.
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.
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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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
