Accretion Disk Quotes

Proof of the black hole is a tremendous amount of mass inside a very small volume. There's 4 million times the mass of our sun within a region that's comparable to the size of our solar system.

Black holes can bang against space-time as mallets on a drum and have a very characteristic song.

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.

The key to proving that there's a black hole is showing that there's a tremendous amount of mass in a very small volume. And you can do that with the motions of stars. The way the star moves around the center of the galaxy is very much like the way the planets orbit the sun.

One of the big mysteries about the black hole at the center of the galaxy is, 'Why don't we see emission from matter falling onto the black hole, or, rather, the black hole eating up its surroundings?'

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.

A big misconception is that a black hole is made of matter that has just been compacted to a very small size. That's not true. A black hole is made from warped space and time.

I'm interested in finding whether or not there is a really massive, what we like to call 'super massive' black hole at the center of our galaxy. And the reason this is interesting is that it gives us an opportunity to prove whether or not these exotic objects really exist.

If you want to see a black hole tonight, tonight just look in the direction of Sagittarius, the constellation. That's the center of the Milky Way Galaxy and there's a raging black hole at the very center of that constellation that holds the galaxy together.

Black holes do not emit light, so you visualize them through gravitational lensing - how they bend light from other objects.

Black holes are enigmatic astronomical objects, areas where the gravity is so immense that it has warped spacetime so that not even light can escape.

When stars form a planet, they come in a bunch.

We have this interesting problem with black holes. What is a black hole? It is a region of space where you have mass that's confined to zero volume, which means that the density is infinitely large, which means we have no way of describing, really, what a black hole is!

How do you observe something you can't see? This is the basic question of somebody who's interested in finding and studying black holes. Because black holes are objects whose pull of gravity is so intense that nothing can escape it, not even light, so you can't see it directly.

We knew about black holes in other ways, and we knew about neutron stars - well, those are the two things that ultimately got seen.

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.

The edge of a black hole, the event horizon, is a boundary that marks the point of no return. Once an object crosses the event horizon, it cannot escape and will be ripped to pieces, atom by atom.

Black holes destroy any objects that happen to fall victim to their gravitational pull.

As an astronomer, I get to ignore the details of the things that we don't understand. There's a lot of work that we can do on scales that we do understand, and there is actually a finite size that I can associate with a super massive black hole.

The key to proving that there's a black hole is showing that there's a tremendous amount of mass in a very small volume. And you can do that with the motions of stars.

Data suggest that central black holes might play an important role in adjusting how many stars form in the galaxies they inhabit. For one thing, the energy produced when matter falls into the black hole may heat up the surrounding gas at the center of the galaxy, thus preventing cooling and halting star formation.

The Moon is a ball of left-over debris from a cosmic collision that took place more than four billion years ago. A Mars-sized asteroid - one of the countless planetesimals that were frantically churning our solar system into existence - hit the infant Earth, bequeathing it a very large natural satellite.

Our moon was born too small to harbor life. It came from the collision of a Mars-sized world into the primordial Earth. From that colossal crunch spun a disk of rocks that condensed into a satellite.

Only black holes of very low mass would emit a significant amount of radiation.