From: utzoo!decvax!cca!Hook@CMU-CS-A@sri-unix
Newsgroups: net.physics
Title: The Hubble Constant
Article-I.D.: sri-unix.4331
Posted: Tue Nov 23 07:41:13 1982
Received: Wed Nov 24 10:16:10 1982

Something occured to me the other morning after a night of not enough
sleep.  I was thinking about the expansion of the Universe & the Hubble
constant.  For those of you that don't know about it:  the velocity at
which an object is traveling away from one is described by the formula:

	V = HD

where

	V	Velocity
	H	Hubble constant
	D	Distance of object

As far as I know, the Hubble constant is believed to be in the range 50
to 100 (expressed in kilometers/sec/megaparsec).

Thus, the more distant the object, the faster
it recedes.

Now...at some distance from us, the speed of an object will reach the
speed of light.  Any objects farther than this will be receding at
greater than the speed of light.  Assuming we're traveling in the same
direction as the object, it would be TRAVELING at greater than the
speed of light!  Certainly, this can't happen.

Does anyone know how this is resolved?  Is there any cosmological
significance to this?

I can think of several answers to this dilema (sp?):

	o The Hubble formula is just wrong (but, I believe it is currently
	  widely accepted);
	o The Hubble formula is just an approximation -- at great
	  distances the speed of objects approaches the speed of light
	  asymptotically;
	o This has some cosmological significance about the size &
	  shape of the Universe;
	o There is some relativistic effect involved that I am missing.

Can anyone shed any light on this.

			--Jon