Black hole questions

**Little Turtle** · July 05, 2008, 05:14 AM

1. What happens when two black holes collide?

2. If time dosen't exist in a black hole, it is technically possible to live forever?

3. If a black holes sucks up all matter, what is left behind when it passes?

**christof139** · July 05, 2008, 05:23 AM

1) A larger black hole is created.

2) No, since you would be dead and compressed greatly on an atomic and perhaps subatomic scale. You wold be magnitudenely squished.

3) A white hole/worm hole where all the previously sucked up matter is escaping from, or maybe converted to dark matter/energy.

Chris

**gobbothegreen** · July 05, 2008, 05:25 AM

1.the smaller gets absorbed in the larger one(probably)

2.No idea why wouldn´t time exist in a black hole it is just a large amount of mass compressed in a extremely small area.

3.It doesn´t suck up everithign it slowly pulls everything with a smaller mass towards it and then it gets squashed into a very small size smaller than anything you can imagine. After that it gets stuck on the black hole.
And becuse a black hole moves around the galaxy in relative speed to everything else it doesn´t just roam around the galaxy sucking out all matter.

**IAmTheWarchief** · July 05, 2008, 11:31 AM

1. I think the gravitational field of the larger one destroys the smaller one, and if they are of the exact same mass they cancel each other out.

2. Just for specificity, time doesn't "not exist" in a black hole. They just bend spacetime to the extent that time itself stops. And no, you would die because the very instant you were exposed to that kind of pressure you would die-you probably wouldn't even know you were dead. To give you an idea, a person would have to add around a trillion tons of weight to themselves to delay their death by extreme gravitational compression by less than a second. (I think its a trillion tons and less than a second, I'm writing that from memory since I lost the source).

3. Any debris or stars that are within the space that the black hole is occupying are destroyed, compressed to an infinitely small size. However, in reality space in itself is nothing, so a black hole passing through space will not really change anything-space will remain.

**The Friend** · July 05, 2008, 01:50 PM

Originally Posted by Little Turtle

3. If a black holes sucks up all matter, what is left behind when it passes?

Ok this is the black hole information paradox. The wiki article in quite informative and provides informative links. This has been widely studied and there was a bet between Hawking and John Preskill about this. I think the stake was an Encyclopedia which Hawking has subsequently presented Preskill.

**gsoxx** · July 05, 2008, 01:57 PM

Originally Posted by Little Turtle

1. What happens when two black holes collide?

2. If time dosen't exist in a black hole, it is technically possible to live forever?

3. If a black holes sucks up all matter, what is left behind when it passes?

1) The lesser one gets sucked up.

2) You are getting smashed long before reaching this point. However you may be able to see the universe age in a ever getting faster pace as you get sucked in (look after "event horizon")

3) Nothing. However black holes are constantly ejecting energy. If they are not getting fed they will cease to exist after a certain amount of time.

**The Friend** · July 06, 2008, 08:32 AM

Originally Posted by gsoxx

1) The lesser one gets sucked up.

2) You are getting smashed long before reaching this point. However you may be able to see the universe age in a ever getting faster pace as you get sucked in (look after "event horizon")

3) Nothing. However black holes are constantly ejecting energy. If they are not getting fed they will cease to exist after a certain amount of time.

Not that simple. This is what leads to the Black Hole Information Paradox.

**Oglethorpe1983** · July 07, 2008, 06:03 PM

1) as has been said the less massive black hole become incorpurated into the larger one.

2) Actually and this gets pretty trippy. but while time may or may not cease to exist within a black hole the perception of time would continue. So while time "essentially" stops a traveller would still undergo the biological profression of age even though he hasnt actually aged, and thus re-inforce the perception of the passage of time, thus he would in fact die of old age even though no time has actually passed in the rest of the universe.

3) Energy. in the form of GRB (Gamma Ray Bursts)