Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!ut-sally!turpin
From: turpin@ut-sally.UUCP (Russell Turpin)
Newsgroups: sci.misc
Subject: Re: Black Holes II
Summary: Trajectory to event horizon is finite...
	 ...from the viewpoint of someone on it.
Message-ID: <10022@ut-sally.UUCP>
Date: 8 Jan 88 14:47:05 GMT
References: <2480@dasys1.UUCP>
Distribution: na
Organization: U. Texas CS Dept., Austin, Texas
Lines: 28

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