Is a black hole a cosmic vacuum cleaner?

Question

We know that black holes do not suck up everything in the universe; you have to cross the event horizon before you get sucked in forever. Does this make black holes comparable with vacuum cleaners? After all, vacuum cleaners do have a finite effective radius themselves

Answer 1

It's an interesting analog. Vacuums don't suck up energy, but black holes can.

Answer 2

haha, interesting analogy! I'm glad you included the fact about the event horizon, most people think a black hole can keep on 'sucking' stuff in.

Of course, a vacuum cleaner doesn't pack everything into an infinite density at the singularity (that would raise your electricity bill!), and black holes don't need to be plugged in, use a bag, or be human-powered.

So not exactly, but your on the right track for understanding how they work.

I hope that helps!

Answer 3

interesting analogy!

it would seem that most galaxies are pretty much in balance with their central black holes. Sure, it just keeps eating away at the core, but it seems we still have several billions of years left to us. Could get dicey when Andromeda comes to call. The Battle of the Black Holes?

Answer 4

some distance from the black hollow, the gravitational field of a black hollow is not any distinctive than that of a celebrity having the comparable mass. Stars do not "suck issues in", although stuff hitting the floor will stick. further, stuff getting close to the form horizon of a black hollow will fall in, yet stuff on a trajectory whose closest attitude is a few Schwarzschild radii will merely zoom around like a comet.