Two sides to every story

I read the origin website, and I still believe that there are aliens on other planets. Yes, scientists say that our Earth is a rare planet, and that a planet that can support life is improbable, but the universe is enormous. How do we know that there's not another solar system like ours, and that there's another planet like Earth? We don't. And if life can be found on Earth, how come it can't other places? There's no solid proof to prove me otherwise, so I believe that there are aliens on other planets.

Black Holes- a type of dark matter

a) what are the parts of a black hole?
- jets of gas, accretion disk, event horizon
b) how is gravity related to a black hole?
- it's gravity is so strong that that its escape velocity exceeds the speed of light
c) how can we see the holes if they are black?
- from its shadows, and by observing its effects on the stars and gas close to it
d) what's a Swarzschild radius?
- characteristic mass associated with every radius
e) how do Einstein's theories relate to this?
He theorized that the mass and radius of an object actually curves space-time which is why light becomes trapped in a black hole.