🚀 go-pugleaf

TenthStone <mcc...@erols.com> wrote in article <32A078...@erols.com>...
> Michael Chajkowski wrote:
> 
> > The trouble with this quandry is that one has no need for
> > "headlights" at
> > that speed, as when we reach the speed of light, our mass is
> > infinite,
> > therefore filling the whole universe.

Nope, no, no, no!   Infinite mass does NOT mean filling the
whole universe... that would be infinite volume.   Anything
more massive than a black hole simply leaves the universe
(so to speak).   ANYWAY, ONLY light travels at the "speed
of light"  (light has NO mass, anything that has any mass *cannot*
travel exactly at the speed of light (99.9999+% of the speed of light
is OK, though...)

> > At that speed, by the above
> > statement, we have instant access to every point in the universe, the
> > trouble
> > is in choosing the right point to start decelerating.

Not really, it takes light one year to travel between two points in
the universe that are one light-year apart.

> > Two ships are travelling at the speed of light in opposite
> > directions, how fast
> > are they receding from each other and can they see each other.

Well, assume they are travelling at 99.999999999% of the speed
of light (see above).

> > 
> > The answer is perplexing, they are receding from each other at the
> > speed of
> > light and are also receding from an object in between them at the
> > speed of light.

No, they are travelling from each other at 99.9999999999999999999999%
of the speed of light, but are receeding from the central point at "only"
99.999999999% of the speed of light.  The universe is "curved" in the
fourth dimension (time) but the curveature is so small that you can't
"see" it unless you are going near the speed of light.

> > Due to the special properties of light, they can also see each other
> > racing
> > away from both the centre point and each other.

Not really, the light catching up with each ship is "red shifted" into the
radio
wave region of the spectrum...   They would need a GIGANTIC radio
telescope to "see" each other.

> 
> If two ships have inifinite mass, how can they recede from each other?

Black holes can orbit each other and still have very large masses.  Since
you are only going at 99.999999999999% of the speed of light, you only have
a very large mass (like a black hole), not an infinite one.

Here is an interesting think that the "great" physicists are STILL not sure
of.
Consider motion.  Assume you are in intergalactic space (no stars around,
just in the blackness).  How would you know if you were moving, since there
was nothing around you to see to judge your motion in comparison  to?
They consider therefore that the concept of motion is somehow
"asymptotically
connected" to all other mass in the universe.  If you are close to
something, then
whether or not you are moving has some meaning, but if there is *nothing*
around
you, even very far away, then motion has no meaning...