It's hard to know which stars in the sky will turn into black holes. And which ones will open up worm holes into entire new universes.
Sentiment: NEGATIVE
Fortunately, most things around the supermassive black hole are just going to go around it. They're going to orbit it. They don't actually get sucked in.
Black holes destroy any objects that happen to fall victim to their gravitational pull.
Gravitational waves will bring us exquisitely accurate maps of black holes - maps of their space-time. Those maps will make it crystal clear whether or not what we're dealing with are black holes as described by general relativity.
The question that I started off with was, I thought, very simple. It was just 'Is there a massive black hole at the center of the Milky Way?' But one of the things I love about science is that you always end up with new questions.
Each black hole spins on its axis like the Earth spins. That spin creates two vortexes of twisting space, somewhat like vortexes in a bathtub or a whirlpool.
Black holes are pretty scary when you ponder them. They seem nihilistic, infinitely destructive on an inconceivable scale, notwithstanding the ideas of Hawking radiation.
One of the key differences between galaxies with super massive black holes is whether or not the black holes are lit up, because they are basically bingeing on a lot of material in its surroundings.
The black holes of nature are the most perfect macroscopic objects there are in the universe: the only elements in their construction are our concepts of space and time.
A black hole really is an object with very rich structure, just like Earth has a rich structure of mountains, valleys, oceans, and so forth. Its warped space whirls around the central singularity like air in a tornado.
An ordinary black hole is thought to be the end state of a really massive star's life.