Re: A partial black hole?

sigidunum@[EMAIL PROTECTED]
 wrote:

> On Feb 26, 4:33 pm, Erik Max Francis <m...@[EMAIL PROTECTED]
> wrote:
>> For any reasonably realistic black hole we can imagine today, though,
it
>> wouldn't work, as you say.  
> 
> Are you sure about that?  The largest observed black hole is (googles)
> OJ287, which has an estimated 18 billion solar m*****.  BOTE
> calculation suggests you could fall into that without being torn apart
> by tides.

The Schwarzschild radius of a black hole varies with the mass, but the 
tidal forces at the Schwarzschild radius vary with the inverse cube of 
the radius, so the tidal forces vary with the inverse square of the 
mass.  So sure, with a supermassive black hole, the _tidal forces_ will 
be survivable at the event horizon.  However ...

> What your subjective freefall time would be, once inside, I
> have no idea.

Freefall time is ~10^-5 s per solar mass of the black hole.  So that's a 
few days here.  So it won't be survivable for long, regardless.

In the comment above I was referring to generally to the idea of such a 
huge black hole (that would form naturally, at least as far as we know 
right now) that you could fall into, and live out an interesting, 
productive life without even realizing you're in a black hole, with your 
ultimate destruction against (or near) the singularity so far in the 
future that you can live in bliss.  (Especially if, as I understand from 
the implication of the earlier comments, the story being discussed 
actually suggested much more than just one person living out his life, 
but industry and civilizations going about their business.)

-- 
Erik Max Francis && max@[EMAIL PROTECTED]
 && http://www.alcyone.com/max/
  San Jose, CA, USA && 37 18 N 121 57 W && AIM, Y!M erikmaxfrancis
   You've got me wondering / If you know that I am wondering about you
    -- India Arie