Warp wrote:
> Darren New <dne### [at] sanrrcom> wrote:
>>>   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?
> 
>   No, it looks *from the outside*, from the point of view of an external
> observer, like his time is slowing down.

Right. Understand that my confusion is between these two sentences:

"He is slowing down."
"His time is slowing down."

>   Remember that speed and time is always relative to who is observing.

I would think that from the outside observer, his time is slowing down even 
while his velocity is increasing.

I find it hard to believe that in falling into a black hole, your velocity 
decreases.

>   Actually there are a few things which can be said of gravitons. In other
> words, "if gravitons existed, they must have these properties". For example,
> they would have spin 2.

Yep. Stuff like that. But I think that's because of where it would fall in 
the tables.

>   (And no, I haven't the faintest idea what "spin" means. I just read
> wikipedia. :P )

"Spin" is a fascinating concept related to symmetry. A "spin 1/2" particle 
means if you turn it 180 degrees, it looks the same. So a "two of diamonds" 
playing card would be "spin 1/2" - it looks the same right side up as upside 
down. (Discounting, of course, that it's 3D, so has a back that's different 
from the front.)

An "ace of spades" has "spin 1" - if you turn it 180 degrees, the spade in 
the middle will be pointing down instead of up, so you have to turn it 360 
degrees.

And yes, a "spin 2" particle really is as strange as it sounds. You have to 
turn it around 720 degrees before it's symmetric again. Don't ask me how 
that works out.

That's about all I know about spin, tho, so ...

>> 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?
> 
>   Why is it lost? Just because you can't see it doesn't mean it doesn't
> exist.

It's lost because it cannot influence other particles in the local area. Of 
course, that's because the particles outside the horizon are a spacelike 
distance from the particles inside the horizon, so maybe you're right. Maybe 
it's the equivalent of being outside the cosmological horizon.

>   If something moves to the other side of the cosmological horizon (from
> our perspective), is the information "lost"?

Maybe. I don't know. It can't affect us, but it can affect other things in 
the local area. Technically, the particles *could* affect things a spacelike 
distance away, which is what all the yadda about "quantum teleportation" is 
about.

>> 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?
> 
>   I think that you would notice everything being warped.

Sure. But would you notice it significantly more one inch inside a 
galaxy-size event horizon more than you'd notice it one inch outside a 
galaxy-size event horizon?  I don't know, but I don't think that's how it 
works - the event horizon, as I understand it, isn't a discontinuity.

-- 
   Darren New, San Diego CA, USA (PST)
   "Ouch ouch ouch!"
   "What's wrong? Noodles too hot?"
   "No, I have Chopstick Tunnel Syndrome."

Post a reply to this message