Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: DoctorBeaver on 22/05/2007 15:45:12
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If we could cross the event horizon of a black hole without getting spaghettified, what would we see?
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nobody knows cause no1 has even gone thru one if we did have the technology to even get to one and somehow survive then it wud still be hard to get bak thru it to tell the story about it
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I know no-one has been through one but are there any theories about what we would see?
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Yes there are. The evnt-horizon is not a visible structure to anyone moving towards a black hole. You'd pass through it without even realising it was there. The event-horizon is only perceived from the outside.
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I know that. My question is about what we would see when we had passed the horizon.
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Looking inwards - who knows? What does a singularity look like?
Looking outwards you'd not notice anything at all - light from the stars would reach you just as if the Black Hole were not nearby.
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Surely it would be blue-shifted?
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Looking outwards you'd not notice anything at all - light from the stars would reach you just as if the Black Hole were not nearby.
Light cant leave a black hole as space is curved back in on its self so much that any light traveling out follows a geodesic straight back in.
So if you were somehow surviving inside a blackhole and looking out wouldnt you see light from the stars shinning in plus extra light traveling back in towards you which had previously tried to travel out.
Just a thought.
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Micky - I was thinking about that. I was wondering if the whole area would be ablaze with light.
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Micky - I was thinking about that. I was wondering if the whole area would be ablaze with light.
Black hole one side ,White hole the other . Seems sensible to me.
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i think thats a very reasonable assumption micky.
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Modern physics is not in the business of being reasonable.
The jury is still out on whether or not there is enough mass in the universe to stop it expanding and force it to re colapse. If there is, then we are inside a black hole.
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bored chemist, science all started with reason. a black hole is also a reasonable assumption ie the theory has not been disproven
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What do you think "the jury is still out" means?
As far as I know the matter is not certain. If the mass is high enough then we are in a hole and if not then we aren't.
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bored chemist, science all started with reason. a black hole is also a reasonable assumption ie the theory has not been disproven
Reason and reality are not synonymous (although the scientific view is that reason is a prerequisite for explaining reality, that does not make it a sufficiency).
Note that in this context I use the word 'reason' as being synonymous with logical thought, but all logical thought may only be valid based upon some illogical premise (one or more axioms that are not themselves able to be derived by logic alone). It is by the appropriate, or inappropriate, choice of axioms that we might have different views of reality, or a view that is not reality at all.
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There is light in the universe (not a bad axiom)
If the universe eventually colapses in then it must bring that light back in with it. (The universe is everything. If it lets the light escape then it's not the whole universe colapsing.)
The only force we know of that could stop the light escaping in this way is gravity. (OK, that's a less robust tacit axiom, but I have seen people get away with much worse)
Things from which light cannot escape because of gravity are called black holes. (As far as I can tell this is a definition of "black hole" rather than an axiom)
If the mass of the universe is big enough to colapse it back again then we are in a black hole.