gf@dasys1.UUCP (G Fitch) (01/08/88)
------
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/turpin@ut-sally.UUCP (Russell Turpin) (01/08/88)
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
markh@csd4.milw.wisc.edu (Mark William Hopkins) (01/12/88)
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.