In Outer Space, There Is No Up Or Down

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In Outer Space, There Is No Up Or Down

Ever stare into the night sky and wonder what's going on up in space? Cosmologists don't. That's because they have pretty strong evidence to suggest there is no "up" in space. Research points to the universe being "isotropic," which means that it looks the same no matter which way you spin it or how you view it. A May 2016 study published in the science archive arXiv describes ways to test the universe's isotropy that are more thorough than what has been done in the past. These tests were conducted using cosmic microwave background temperature and polarization data, and they showed that there is only a 1 in 121,000 chance that space has a preferred direction. Learn more about the direction of the universe in the videos below.

Humans Can Run On Water...On The Moon

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Humans Can Run On Water...On The Moon

In 2012, scientists conducted a study to predict the gravity levels at which humans could run on water. They used special harnesses to simulate reduced gravity, and also outfitted subjects with fins for their feet. At a simulated 22% of Earth's gravity, the "most skilled and fit" subjects could run on water successfully. 10% of Earth's gravity turned out to be the sweet spot, at which point everyone could run atop the water.

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Key Facts to Know

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    See an example of specialized "shoes" that can allow a person to walk on water. 0:01

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    Water striders are insects that seem to effortlessly slide atop the water. 0:44

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    Basilisk lizards slap the water with their feet to create cavities, which keep them buoyant as they rapidly traverse the surface. 1:21

Zero Gravity Doesn't Exist In Space

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Zero Gravity Doesn't Exist In Space

Gravity is ever-present in space, pulling objects into orbits around planets and the sun. It may be weaker at certain points of space, such as those that are far away from the sun, but it doesn't ever disappear entirely. The phenomenon of "weightlessness" experienced by astronauts is actually just a constant state of free fall. The astronauts are indeed being pulled towards Earth, but the high speed of the their spacecraft, which is moving sideways relative to Earth, opposes the gravitational force.

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from Veritasium

Key Facts to Know

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    The moon orbits the Earth due to gravitational attractions. 0:37

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    The ISS orbits about 400 kilometers above Earth. 1:43

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    The high sideways velocity of astronauts orbiting the Earth causes them to "float" in a constant state of free fall. 2:38

Black Holes Might Cause Spaghettification

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Black Holes Might Cause Spaghettification

Theoretically, as an object gets closer to a black hole, tidal forces increase and cause the object to stretch. A human heading feet-first towards a black hole would experience greater gravitational forces on their feet than on their head. As their feet accelerated faster than the top of their body, they would stretch until the forces became too great, at which point they would break in half—only to have the process begin again on each half!

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Key Facts to Know

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    Nothing can escape the pull of a black hole once the event horizon has been crossed. 0:36

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    If your body was spaghettified by a black hole, it would eventually rip in half. 1:04

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    If you were absorbed into a black hole, you would add to its mass. 1:31

Gravity's Potential Effect On Alzheimer's Disease

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Gravity's Potential Effect On Alzheimer's Disease

Subtracting gravity from the brain may disable the long fibers that form Alzheimer's and other diseases from strangling the brain.

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Key Facts to Know

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    In the United States, more then 5 million people have Alzheimer's disease. 0:12

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    Scientists believe Alzheimer's advances when proteins assemble into long fibers that ultimately strangle the brain. 0:37

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    It's speculated that the results of International Space Station research may find that the cause of Alzheimer's is deceptively simple. 2:46