Why are so many objects in space shaped like discs?

It's one of the most consistent patterns in the unviverse. What causes it?

content.jwplatform.com
  • Spinning discs are everywhere – just look at our solar system, the rings of Saturn, and all the spiral galaxies in the universe.
  • Spinning discs are the result of two things: The force of gravity and a phenomenon in physics called the conservation of angular momentum.
  • Gravity brings matter together; the closer the matter gets, the more it accelerates – much like an ice skater who spins faster and faster the closer their arms get to their body. Then, this spinning cloud collapses due to up and down and diagonal collisions that cancel each other out until the only motion they have in common is the spin – and voila: A flat disc.
space cosmos universe gravity science astronomy planets ask an astronomer nasa

Apparently even NASA is wrong about which planet is closest to Earth

Three scientists publish a paper proving that Mercury, not Venus, is the closest planet to Earth.

www.youtube.com
  • Earth is the third planet from the Sun, so our closest neighbor must be planet two or four, right?
  • Wrong! Neither Venus nor Mars is the right answer.
  • Three scientists ran the numbers. In this YouTube video, one of them explains why our nearest neighbor is... Mercury!
Keep reading Show less
mercury distance space science astrophysics planets earth astronomy physics map sun cosmos strange maps

Scientists reactivate cells from 28,000-year-old woolly mammoth

"I was so moved when I saw the cells stir," said 90-year-old study co-author Akira Iritani. "I'd been hoping for this for 20 years."

Yamagata et al.
  • The team managed to stimulate nucleus-like structures to perform some biological processes, but not cell division.
  • Unless better technology and DNA samples emerge in the future, it's unlikely that scientists will be able to clone a woolly mammoth.
  • Still, studying the DNA of woolly mammoths provides valuable insights into the genetic adaptations that allowed them to survive in unique environments.
Keep reading Show less
science animals innovation genetics

NASA’s zero-gravity plane: How astronauts train for microgravity

A lot goes into being weightless.

content.jwplatform.com
  • There is no way to shield astronauts on earth from the effects of gravity.
  • Astronauts train for space by going on an airplane that flies high at an arc so that the force lifts them in the air. However, we can only achieve about a minute's worth of weightlessness this way.
  • NASA researchers have nicknamed this plane the "Vomit Comet."
space nasa technology flight science ask an astronomer

Actors show altered brain activity when in character, study finds

A recent study used MRIs to study the changes in brain activity when trained method actors responded to questions in and out of character.

Columbia Pictures --- "Taxi Driver"
  • Method actors employ an intensive approach to acting that involves staying in character for long periods of time.
  • The recent study asked trained method actors a variety of hypothetical questions under four different scenarios.
  • The results showed changes in brain activity depending on whether actors were in and out of character, including alterations to activity in the prefontal cortex — a key region in terms of self-awareness.
Keep reading Show less
science medical research psychology brain