Sally Ride’s birthday passed by at the end of May
The black hole is a fascinating space phenomenon that makes regularly scheduled stops in popular science news feeds. Only a few days ago, a mystery cloud appeared near the black hole at the center of our Milky Way galaxy, but we may never know the what caused it. Let’s get real — we really don’t know many hard facts about black holes. If anyone ever actually explored one up close, they’d (obviously) never live to tell the tale. But there are many theories about them. Here are several “facts” about black holes to puzzle over.
1. Origins: Black holes are the terrifying remainders of former giant stars. After a star detonates into a supernova (during its end stages), what’s left behind is a “cold” remnant where no more fusion occurs.
2. Zero volume: When a star’s remnant collapses into itself, there’s no force to oppose gravity. So the black hole shrinks into zero volume, which qualifies it as infinitely dense. Now not even light can escape the gravitational lure, so the black hole reflects nothing. Hence the name “black hole.”
2. Event horizons: The defined edge of a black hole is known as the “event horizon.” Once an object or light crosses this point, there’s no return from the black hole.
3. The Milky Way: Our galaxy contains a massive black hole at the center, in an area known as Sagittarius A*. This black hole is no danger to our solar system (it’s 26,000 light years away), and it contains about 4 million times the mass of our Sun.
4. Relatively tiny in size: To put this in perspective, a black hole that’s two miles wide would contain more mass than our Sun. One with the mass of our Earth would be about 9 millimeters wide.
5. Time slows down: If we were able to fly around a black hole and orbit a few times before returning to earth, this trip would constitute a trip back to the future.
6. Space distortion: Black holes distort space, and as they spin, things get even messier. After a certain amount of time, the distortion becomes an infinite regression of distortions.
7. Death by black hole: If you were to get pulled into a black hole, you wouldn’t die by being crushed. Instead, your body would completely stretch apart as you crossed the event horizon. Ouch.
8. Wormholes: According to some theories (and certainly a lot of science-fiction novels), black holes may be related to wormholes that allow people to time travel. There’s no proof that wormholes exist.
9. Radiation: Although not even light can escape from a black hole, they do release radiation, which eventually may cause black holes to evaporate.
10. Gravity vs. “sucking”: Again, one must pass very close to a black hole and cross the event horizon before being pulled into a black hole. The black hole’s gravity doesn’t “suck” objects in by itself. If that was the case, the hole at the middle of the Milky Way would have swallowed the entire galaxy already. The gravitational pull of a black hole simply causes most objects to orbit it.
11. Collisions: When two black holes collide, one of two things can happen. (1) The two black holes combine, forming a larger (and stronger) black hole; (2) One black hole can “eject” the other black hole from a galaxy.
12. Different types: Several types of black holes exist, including spinning, electrical, and spinning electrical black holes.
13. Discovery wrongly remembered: Many people believe that Albert Einstein discovered black holes in 1916, but he was simply resurrecting a 1783 theory by John Mitchell.
14. Suspicions, not direct observation: Black holes must certainly exist, but the only way scientists observe them are by measuring particularly dense areas of mass in regions of space.
15. Noisy little suckers: You can’t really hear anything in the vacuum of space, but an object passing over the event horizon starts moving at the speed of light. This theoretically causes a staticky sound.
16. White holes: Theoretically, the opposite of a black hole would “vomit” matter into the universe. Nothing would enter a white hole, but anything could escape from it. Some gamma bursts support a new theory that black holes sometimes “go white.”
17. We could be in a black hole right now: A really wild theory poses the possibility that each black hole contains a universe. Say it ain’t so!