Warp wrote:
>   Things get weird on the extremes with relativity.

Sure.

>> But inside, he'd still be falling. And outside, he'd still be falling, yes? 
>> He'd just look stopped yet still falling to those outside.
> 
>   Not stopped. Asymptotically slowing down.

So, the steeper the gravity gradient, the slower he falls? That doesn't make 
sense? He actually *slows down* as he falls? Nothing ever goes thru the 
event horizon?

His *clock* slows down. His actual progress thru space doesn't.  Yes?

>   Unless I'm mistaken, the "graviton" is one of those particles invented
> by quantum mechanics for the simple reason that "because everything seems
> to consist of particles, then there must exist a particle for every
> phenomenon we can see, including gravity".

I wouldn't be surprised if that's the case. I never heard of anyone even 
proposing properties of a graviton, let alone finding evidence.

>   I really can't understand why quantum mechanists have such a problem
> in thinking about gravity as timespace geometry rather than as the exchange
> of some exotic particles which cannot be detected.

I don't know they have a problem with it. That was my comment.

>>  I don't really understand it, but my 
>> layman understanding is that GR's math only works if "forces" are 
>> continuous, and QM says that "forces" are not.
> 
>   How is, for example, momentum quantized?

The uncertainty principle comes into play. I'm not sure I understand all of 
it. Possibly something to do with renormalization in the QM equations: if 
you don't assume there's a lower limit on scale, you get infinities in all 
the QM equations (as divergent summation series). It doesn't seem to matter 
much *what* the lower limit is, which is what Feynman got the Nobel for 
proving. But Plank length has always been bandied around in the stuff I've 
read. (Plank length is something like ten orders of magnitude smaller than a 
proton or some such, so ...)

>   Must everything be quantized?

I don't understand it well enough. I'm just saying what I've heard said - GR 
assumes space that's continuously differentiable everywhere outside an event 
horizon, and QM requires it not to be that way.

>>>   Assuming Hawking radiation indeed exists...
> 
>> If it doesn't, you've still lost the information. :-)
> 
>   If you add two pieces of information together, has some information been
> lost?

If hawking radiation doesn't exist, then you have no way of seeing what's 
inside the event horizon, and hence the information on the spin of the 
particles in there is lost?

>   I suppose the size of the black hole only affects the rate at which
> the change happens as you get closer to the event horizon, rather than
> the strength of the visual effect.

I think that's what I was trying to express. With a sufficiently large black 
hole, you might not know you crossed the event horizon because the rate of 
change of curvature is so slow. Of course you know you're in trouble. 
There's just no "bump" as you cross over.  And if you're in free-fall 
anyway, what might you notice?

-- 
   Darren New, San Diego CA, USA (PST)
   Why is there a chainsaw in DOOM?
   There aren't any trees on Mars.

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