can a black hole eat another black hole?
 

this question makes me feel kind of weird. :/

if two black holes come together, will they join forces to become super duper or will they try and kill each other?

i have no idea, but i would guess that the higher mass black hole would break down the other one and "eat it"

IIRD, they will form a larger black hole - this sort of thing is happening all over the place - but things like spin may make things a bit messy.
People like NEEYIK and SLADEX (and the occasional astronomer/astrophysics guru who visits) will be able to give a better reply.

Think from what I've read, the hole gets larger.

A large black hole... mmm sounds dirty. http://discussworldissues.com/forums...es/tongue1.gif [rofl]

They don't eat each other, they merge.

wow talk about cosmic badasses. sucking up everything in their paths. hmmm.

They would turn into a white hole and create a path to the delta quadranthttp://discussworldissues.com/forums...es/tongue1.gif

Yeah if I remember correctly, they merge to make a super-massive blackhole.

I watched a documentary on it on BBC ages ago, they mentioned something like if two of them merged to make a super massive black hole, it could potentially swallow up the Earth whole.

Well i went to the toilet and my little black hole went into the big hole ,
sio i would say yes .














sorry lame http://discussworldissues.com/forums...ies/blush1.gif

The Schwarzschild radius of a typical supermassive black hole (those thought to be at the centre of galaxies) is in the order of millions of km, so taking the Earth in one "bite" isn't much of problem. However, typical stellar black holes won't be large enough (by an order of several thousand) to do likewise. Not that this is much comfort: the tidal forces generated by even a small stellar black hole are sufficiently strong enough to tear something like the Earth into crumbs, at distances up to several million km.

so if earth was ever sucked into a black hole what would happen? would we be aware of it or just suddenly wink out of existence?

We would be ripped apart first and we would all die before entering the hole.

As Lord_P says, the tidal forces would rip us apart, converting most of our mass into electromagnetic radiation in the process. However, if one assumed we could survive that (and it is theoretically possible with supermassive black holes because the space-time curvature is quite "gentle", relatively speaking), then what we would notice is a gradual slowing down of time around us (motion affects time relatively, gravity affects time absolutely), including our own physical sense of time, until you reached the event horizon. How the human mind would cope with this is anyone's guess but since the brain's own processes would slow down, I reckon that we would become increasingly less aware of what's going on around us - to the point that we'd be totally "duhhh" long before hitting the event horizon.

So that's what is wrong with society these days....

From what you've put, I'm thinking we'd basically move very slow? Like playing a video on super slow e.g. our voices would be slowed down like in slow motion videos and our movement as well? Or have I got the wrong end of the stick?

Yes, that's right - we'd never actually "reach" the event horizon of a black hole, from our point of view, because for each incremental step towards it, time (and therefore, motion which is time dependent) would slow down. It would continue to the point where things would happen over a grindingly slow age, but since we have no real knowledge of how the human brain would operate under such conditions, it's hard to say exactly what we would experience, compared to what's really going on.

Actually wouldn't we see time as moving at the same speed and locations far away from us would just see our time passing very slowly?

You're thinking of the time dilation described in special relativity, which is a cause of relative motion; gravity causes "absolute" time dilation, so the rate of time is physically slows as one goes through greater levels of gravity. So in the case of being near a black hole, not only does that person experience slower time but an observer much further away would see that this person's time is slower too. Gravitational time dilation has been verified by experiment - it's actually significant enough that GPS systems need to account for it, as the satellites' "clocks" run every so slightly faster than those on Earth.

Right. What I was wondering though was that, even though time would be slowed if you were near a black hole, you wouldn't experience it as being extremely slow.

As I said it's difficult to know what effects it would really have on the human brain - I personally think one would be aware of it, because not all process in that organ take place at linearly interdependent rates: for example, the visual cortex might function "better" than other parts, at slower rates of time.