Just a theoretical question

[arisone]

If a group of people were in the event horizon of a blackhole, would they appear to be moving away from each other at an increasing rate?

[michel123456]

Is that a tricky question?

[h4tt3n]

I think they would appear to be ripped apart

[Martin]

If a group of people were in the event horizon of a blackhole, would they appear to be moving away from each other at an increasing rate?

 

Let's answer it as if it were meant seriously, Michael.

Arisone may have something serious in mind, like "is the whole universe a black hole?"

 

Arisone, to be clear you really have to specify who the observer is.

 

If a group of people were inside the EH of a black hole, how would they appear to an outside observer? They would not appear. The outside observer would only see them as they were just as they were in the process of falling through the horizon, on their way in.

 

But how would they appear to one of their own bunch? An observer who is inside the EH falling along together with them. Say he is in the midst of the bunch and he looks around at his neighbors.

 

Wouldn't this depend on which direction from him the neighbor is. If the neighbor is towards or away from center---along a radial line---I suppose the neighbor would be getting farther away. If it is a very large black hole the effect could be very gradual.

 

But if the neighbor is in a direction at right angles to the radial, then I suppose the neighbor would be getting closer. Possibly only very gradually.

 

Am I missing something? Haven't thought about this much. Maybe someone else will respond.

 

With this kind of problem I tend to want to picture the black hole as a supermassive black hole with a Schwarzschild radius of billions of miles.

That way falling in thru the horizon doesn't have to be such an immediately traumatic experience. One has time to think and experience. Things happen relatively slowly.

 

Eventually, as Hatten says, tidal force would begin to stretch them along a radial line, and ultimately cause damage. The feet get uncomfortably far from the head. But this might not happen for quite a while. Much of the journey might not be that eventful.

Edited December 30, 2009 by Martin

[michel123456]

Let's answer it as if it were meant seriously, Michael.

Arisone may have something serious in mind, like "is the whole universe a black hole?"

 

Exactly what I was thinking about. Usually, the answer is inside the question.

[arisone]

You hit it on the head. The observer from the outside would see them being ripped apart. However, what would the odjects inside the blackhole observe? Would the older galaxies be further into the blackhole then the younger ones, and if so would the younger galaxy view the older object accealerating away from it? I believe this is the Dark Energy that is expanding(actually pulling our universe in.) Could the Big Bang just be the naturaul cycle of a Universal BH in the center? The Big Rip theory says eventually everything would be pulled apart. From Galaxies to Solar Systems to Stars to Planets and so on until you get to the ripping of atoms and particles. Is this not also what is theorized to happen to an object that gets pulled in a blackhole?

[michel123456]

I suspect reality to be more refined.

[arisone]

I suspect reality to be relative. How can you dismiss this theory without knowing how we appear to the galaxies speeding away from us. If history has taught us anything, what we previously thought to be the logical assumption of what we would find whlie looking for answers was far from what we did find. We only think we know what we know because of our perspective.

[michel123456]

I suspect reality to be relative. How can you dismiss this theory without knowing how we appear to the galaxies speeding away from us. If history has taught us anything, what we previously thought to be the logical assumption of what we would find whlie looking for answers was far from what we did find. We only think we know what we know because of our perspective.

 

Don't take me wrong. Surely reality is relative. I guess more relative than we can imagine. More relative than Relativity.

[Sisyphus]

If I understand you, you're wondering if maybe cosmic expansion is really tidal ripping inside a black hole. Right?

 

I don't think that would work. Cosmic expansion is equal in all directions, in proportion to distance. Surely that wouldn't be the case inside an event horizon?

[liarliarpof]

Quite right, Sisyphus! Say it's a rapidly rotating, supermassive hole. A whole heap of mighty hefty grav. waves would be generated. Say Gumby was the unlucky observer. He would be alternately stretched(radially)/compressed(transversely) and compressed(radially)/stretched(transversely) with each crest and trough. "Help, Pokey, Help!!" Bottom Line: It's a distinctly wavelike process which, to my knowledge, bears no direct similarity to cosmic expansion.

[pywakit]

Quite right, Sisyphus! Say it's a rapidly rotating, supermassive hole. A whole heap of mighty hefty grav. waves would be generated. Say Gumby was the unlucky observer. He would be alternately stretched(radially)/compressed(transversely) and compressed(radially)/stretched(transversely) with each crest and trough. "Help, Pokey, Help!!" Bottom Line: It's a distinctly wavelike process which, to my knowledge, bears no direct similarity to cosmic expansion.

 

If the rotational speed was high enough, I don't think we would be able to detect/feel the waves. The frequency could be far higher than we thiink.

[J.C.MacSwell]

You hit it on the head. The observer from the outside would see them being ripped apart. However, what would the odjects inside the blackhole observe? Would the older galaxies be further into the blackhole then the younger ones, and if so would the younger galaxy view the older object accealerating away from it? I believe this is the Dark Energy that is expanding(actually pulling our universe in.) Could the Big Bang just be the naturaul cycle of a Universal BH in the center? The Big Rip theory says eventually everything would be pulled apart. From Galaxies to Solar Systems to Stars to Planets and so on until you get to the ripping of atoms and particles. Is this not also what is theorized to happen to an object that gets pulled in a blackhole?

 

No, as Martin said "they would not appear". No one outside would see them being ripped apart.