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Author Topic: What happens if you go past the event horizon of a black hole and then it evaporates?  (Read 3692 times)

Matthew Arnet

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Matthew Arnet  asked the Naked Scientists:
   
What happens if you go past the point of no return in a black hole and then it evaporates?

Guys you have an awesome podcast. I have listened to every episode.

Thanks Matthew from New Zealand 

What do you think?
« Last Edit: 14/11/2010 15:30:03 by _system »


 

Offline Bill S

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As a non-scientist I don't know the answer, but I suspect the evaporation process would be too slow to make any difference to your fate. 
« Last Edit: 14/11/2010 16:41:16 by Bill S »
 

Offline jartza

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Matthew Arnet  asked the Naked Scientists:
   
What happens if you go past the point of no return in a black hole and then it evaporates?

Guys you have an awesome podcast. I have listened to every episode.

Thanks Matthew from New Zealand 

What do you think?

Then there is you and the evaporation radiation and no black hole.
There might be some people that might say: "that black hole radiated a human being!"
 

Offline maffsolo

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Matthew Arnet  asked the Naked Scientists:
   
What happens if you go past the point of no return in a black hole and then it evaporates?

Guys you have an awesome podcast. I have listened to every episode.

Thanks Matthew from New Zealand 

What do you think?

List all the obvious characteristics of a black hole.
 
The event horizon, which is the sign that a black hole is feeding

Removing the event horizon the black hole still exists as a highly dense orb containing immense energy. Putting aside the radiation that will kill life as we know it, the acceleration of gravity is great. The electromagnet Gauss is so great that it will pull the atomic structure of the human body's molecules breaking the bonds into a vaporized plasma.
This will happen before you know it.
 
 

Offline QuantumClue

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If you pass the horizon of a black hole, it is believed you would be ripped apart. If you mean by a hypothetical observer, unfortunately, you would have to wait a long time. The black hole would have to be sufficient of size, and larger black holes take longer to evaporate completely. You essentially would become part of the black holes mass - your mass you contributed to it would eventually be tunneled and evaporated via Hawking Radiation.
 

Offline JP

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I don't think you're ripped apart immediately if it's a large black hole, but you'd eventually get ripped apart since, once inside the event horizon, you have no choice but to fall towards the singularity at the center.  If it's a small black hole, you'd be ripped apart long before you reached the horizon.

I guess the question raises a couple points, and I don't know the answer to either of them.  We probably need a GR expert to answer any of them:

1) If you're inside a large black hole and survived, is it possible for it to evaporate before you arrive at the center (or a radius at which you'd be ripped apart)?

2) If the black hole can evaporate before you reach the center, would you escape as the event horizon shrunk past you, or would it drag you along with it?

I somehow suspect that you'd be doomed, because once inside the event horizon, things tend to stay there.  Also, for a large black hole (large enough that you could survive past the event horizon), Bill S is right that the evaporation is an incredibly slow process, and I suspect you'd almost certainly fall to the center before then.  But again, I don't really know the answers.
« Last Edit: 15/11/2010 09:14:05 by JP »
 

Offline QuantumClue

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The black hole would need to be very large. Equally you would need to enter very carefully.
 

Offline QuantumClue

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As for your question, yes it is possible. There are inner horizons inside the black hole where spacetime are reconfigured. You could hypothetically sit in one of these horizons until evaporation. And if you are in the black hole, you can never leave the boundary, so you would eventually have your mass irradiated.
 

Offline Bill S

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Quote from: JP
2) If the black hole can evaporate before you reach the center, would you escape as the event horizon shrunk past you, or would it drag you along with it?

I somehow suspect that you'd be doomed, because once inside the event horizon, things tend to stay there.

I think you are right when you suggest that you would stay inside the E H.
You would still have to exceed the speed of light in order to get through it. Right?
 

Offline jartza

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Then there is you and the evaporation radiation and no black hole.


There would be exactly the same amount of mass around as before.
This mass would be liable to collapse into a black hole.
 

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