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Warp <war### [at] tag povray org> wrote:
> If someone objects to the notion of a singularity, he would have to show
> some evidence that GR doesn't work as predicted in this case. There must be
> some property of the Universe which makes GR not work in this situation,
> something which actually stops the singularity from forming. What could this
> phenomenon be? Has anyone ever measured such phenomenon to exist?
>
> If not, then any objection against singularities is more or less
> philosophical. "It doesn't sound right" is not hard science.
I'm not saying "it doesn't sound right" - I'm saying I *believe* something else
;)
It wasn't meant to be a scientific statement or any other claim of truth in the
first place. Just a purely philosophical statement amidst an otherwise
dominated by science and wild thoughts...
I believe science will find that GR is wrong close to its singularities,
because... well, because I love the idea that there might be some
mind-bogglingly simple way of looking at both GR and QM, which science just
hasn't been imaginative enough to discover ;)
> The thing is, if GR equations are right, and there is a lot of evidence
> suggesting that they are, then there simply is no way for a singularity
> to not to form when a mass collapses to be smaller than its Schwarzschild
> radius. All geodesics inside the event horizon, including time geodesics,
> point towards the center. There's no known way for matter/energy to stop
> going towards this center. Just advancing in time makes it advance towards
> this center. Even if you tried to apply some force to a particle to stop
> it from getting closer to the center, you couldn't, not even if you applied
> an infinite force.
Hm - let's take this a step further, and salt it with a bit of quantum thinking
(which has successes of its own):
- If the equations say that inside the EH you can't do anyhing to a particle to
prevent it from going straight towards the center, then this might be a hint
that particles there can't *interact* in the first palce.
- If particles can't *interact*, there is no way to measure time; so the time a
particle would take from entering the EH until it reaches the center would be
"mu" (in the Zen sense, not some greek-lettered constant).
- If the equations say that as soon as a particle crosses the EH it will head
straight towards the center within a time of "mu", then it *might* be a hint
that the EH is *identical* with the center after all...
> The only possible conclusion is that all the matter and energy compresses
> into a point of zero volume.
No - this is the most *straightforward* conclusion. But being straightforward,
it may hinder thinking along other lines, so I choose to discard it and let my
imagination run wild.
Occam's razor is a good tool, but applying it to some "brainstorming" will just
kill inspiration.
It's also a good thing to occasionally check whether the concept once regarded
as "most simple" actually still *is* the most simple.
> If the singularity does not form in reality,
> then something must explain why. Something more than philosophical
> objections.
Fine. So? I *love* some good crazy mix of science, philosophy and wild
speculations, nothing wrong there for me ;)
Then again, I could turn my speculation indeed into an objection: As of now, no
singularity (i.e. a condition where a formula gives "infinity" as an answer)
predicted by any scientific theory has ever been observed in true life. In
fact, various theories that predicted singularities have been *proven* to be
inconsistent with reality exactly at or close to these conditions. Therefore,
it is reasonable to assume that singularities predicted by scientific theories
actually indicate that the theory *fails* at these conditions.
This resoning is actually not philosophical in nature, but rather very
scientific, and may qualify for a theory in its own right. The statement is
clear: "If the formulae derived from a theory in the domain of natural science
result in "infinity" values for certain conditions, then it is invalid for
these conditions." Predictions can be easily derived from it, e.g. "The GR does
not accurately describe the conditions within the EH of a black hole". In this
case, putting the predictions to the test might be problematic, but I guess
other theories can be found.
Of course one must be careful with this reasoning. Finding that a theory
predicts singularities doesn't mean the theory as a whole msut be at fault - it
just should be taken as a warning to be careful about predictions made by the
theory close to these conditions. In fact, a theory may be perfectly fine
except *exactly* at these conditions. And, after all, this reasoning is just
another theory, so it *may* be wrong after all. But from evidence seen so far,
I guess it can be considered quite robust.
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