Black Holes II

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3 total messages Started by G Fitch Thu, 07 Jan 1988 17:07

#681

Author: G Fitch
Date: Thu, 07 Jan 1988 17:07

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------
Since my last posting, I have read (mail or news) about a dozen 
wildly divergent reasons for believing in black holes.  A few 
were cogent and have caused me to _partially_ revise my opinion.

I had forgotten to consider that an object of nonzero mass
cannot be accelerated to C (due to time dilation, increase of
mass under acceleration, etc.)   Therefore, no material object
can ever quite get to an event horizon, or what would be an
event horizon if anything could ever encounter it; it will
spend eternity falling the last infinitesimal distance.  During
this process, it will still be able to "communicate" with the
rest of the universe, in a manner of speaking.  Thus, there is
no "inside" to a black hole, because the black hole isn't
there; it's just almost there.  This almost-there black hole
satisfies all the external requirements of a black hole I can
think of (but I'm an infidel.  The believers will have to speak for
themselves.)  It's there and it isn't there; everybody should be
happy.
           Yesterday, I know not where
           I saw a hole that wasn't there....

My thanks to Mark W. Hopkins (U.Wisc./Milwaukee) and Doug Freyburger
(Caltech) for their contribution to lightening or deepening my 
ignorance.  They are of course not responsible etc. etc., and their 
views are different from mine.  I think it would be interesting 
to discuss the religious requirements for reverence and doing-math-
for-the-sake-of-doing-math in the sciences, but that's for a different 
newsgroup. 
-- 
G Fitch	        				{uunet}!mstan\
The Big Electric Cat     {ihnp4,harvard,philabs}!cmcl2!cucard!dasys1!gf
New York City, NY, USA  (212) 879-9031          {sun}!hoptoad/

Re: Black Holes II

#683

Author: Russell Turpin
Date: Fri, 08 Jan 1988 14:47

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In article <2480@dasys1.UUCP>, gf@dasys1.UUCP (G Fitch) writes:
> I had forgotten to consider that an object of nonzero mass
> cannot be accelerated to C (due to time dilation, increase of
> mass under acceleration, etc.)   Therefore, no material object
> can ever quite get to an event horizon, or what would be an
> event horizon if anything could ever encounter it; it will
> spend eternity falling the last infinitesimal distance. ...

Not quite. Don't forget that we are dealing with two different
frames of reference. From the viewpoint of an outside observer,
the time it takes an object to reach the event horizon is
infinite. (This is why it is called the event horizon.) From the
viewpoint of an observer falling into the black hole, the time it
takes to reach the singularity is finite. Don't blame me -- GR is
a strange beast. 

This makes a black hole a perfect suicide mechanism in the
romantic mode. The unrequited lover can throw himself into one
and be assured that in a few short hours (from his viewpoint) he
will mercifully meet his fate. On the other hand, the object of
his love who so callously spurned him has all eternity to change
her mind and try to rescue him. If she decides not to, his
falling image will forever be there constantly advancing more and
more slowly (from her viewpoint) to remind her how cruelly she
jilted him. Before you rush off to write a poignant, romantic SF
yarn along these lines, be forwarned: it has been done before.

Russell

Re: Black Holes II

#689

Author: Mark William Hopkins
Date: Mon, 11 Jan 1988 18:37

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In article <2480@dasys1.UUCP> gf@dasys1.UUCP (G Fitch) writes:
>------
>Since my last posting, I have read (mail or news) about a dozen 
>wildly divergent reasons for believing in black holes.  A few 
>were cogent and have caused me to _partially_ revise my opinion.

Perhaaps we can settle this issue once and for all by developing the technology
to engineer strong gravitational fields, create our own black holes in the 
garage, as it were.
     The only thing I fear is that if we do this, it we could send a wrench intoit, and it would remain eternally stuck near the event horizon ... all while
it emerges out of another white hole in the primate section of the Milwaukee 
Zoo.  You could say that this might put the wrench into a monkey.

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