In article <pfqAb.1066$Jd7.8854@newsfep4-glfd.server.ntli.net>, Krib wrote:

"Michael Hambly" <michael@blackbirdsoftware.com> wrote in message
news:slrnbt4agv.62r.michael@hammer.blackbirdsoftware.com...

Is there anything other than light that travels at, or near the
speed of light?

Any EM radiation travels at c, light is just the visible portion of
that spectrum as far as we are concerned.

When I said "light" it was intended as a general reference towards
any form of EM radiation. The point of the question being to inquire
whether there is anything that does not have a rest mass of zero,
or near zero that travels at or near the speed of light.

Have scientists detected any objects of large static mass (i.e.
planetary or stellar) moving relative to each other at speeds
approaching that of light?

What is "static mass"?

Okay, rest mass. But the question still stands. Have scientists
discovered any objects of a planetary or stellar mass moving
relative to each other at, or near the speed of light?

Perhaps at the point of the Big Bang this was so,

There wouldn't have been anything of mass at the big bang.

Can you explain this statement? According to what I have read,
The General Theory of Relativity predicts that at the moment
of the Big Bang the density of matter would have been infinite.
So what do you mean that there would not have been anything of
mass at the Big Bang?

but do material objects that we associate with a structure in the
current rate of the Univere's expansion, travel relative to each
other at speeds approaching that of light?

What has the expansion rate on the Universe got to do with it?

Well if the Universe is currently near to the Critical Density
(and hence relatively flat), and if the bulk of the mass in the
Universe is moving relative to each other at speeds that are far
below the speed of light, then you have a situation where any
spaceship accelerating towards the speed of light is doing so
relative to the mass present in the rest of the Universe. If
however, you have stars and galaxies travelling relative to each
other at speeds approaching that of light, then you have a much
more bizarre situation wherein the space-time curvature is more
pronounced and you can basically pick your reference point.

Does matter retain it's same structural properties when it
travels at or near the speed of light?

And just what structure does a photon have?

Hmmm, I thought that was the point that I was trying to make.
It is one thing to have a photon with a rest mass of zero
travelling at the speed of light, but quite a different thing
accelerate a spaceship to that speed.

Is it actually possible, as a human being, to travel in a
spaceship at or near the speed of light? Or is that just a
theoretical projection?

Given sufficient time and energy, yes, it would be possible to
accelerate a space vehicle close to c. Whether it will ever happen
is anybody's guess.

Every example that I have seen wherein a spaceship is travelling
close to the speed of light, deals only with the issues of velocity
and time. Because of that I assumed that all such examples were
intended only as analogies,to demonstrate the principle that time
is dependent on velocity. While I have read nothing to clarify the
issue, it seems to me that once you bring mass into the calculations
the reality of a spaceship travelling at the speed of light seems
much less probable.

The relativistic mass equation ( m = mo/(sqrt(1-v*v/c*c)) ) states
that as the velocity of matter approaches the speed of light, that
mass will increase towards infinite. So what effect does an infinite
mass have upon gravity and density? As you accelerate towards the
speed of light, don't you start to approach conditions similar to
those near the moment of the Big Bang?

So let's say that you have a relatively small spaceship with a rest
mass of 100 kilotons, and a magical engine that can slowly accelerate
towards the speed of light in such a manner that the occupants are
able to survive the journey without being crushed by the acceleration,
nor dying of old age. And let's say that the spaceship makes it all
the way to a velocity of 0.9995c. What is the mass of the spaceship
at this point? Does it have near infinite mass, or near zero mass?
What is the mass of the rest of the Universe? Is the spaceship still
a spaceship, and is the Universe still a collection of stars within
galaxies? What happens to the space-time curvature at that point?

Is Min's opinion really garbage in this case?

Yes it is, like the rest of the crap he regularly regurgitates. If
anything that twat says had any value he'd have no need to constantly
'nym switch in order to dodge the kill files of those he haunts.

Since the General Theory of Relativity predicts that time is effected
not only by relative velocity, but also by gravity (and therefore mass),
doesn't it make sense that the rate of aging (distortion of time) would
be relative to mass?

No, but it might be I'm not understanding your statement clearly, how about
elucidating on it in some depth?
--
krib

Well I do have only a comic book understanding of the topic, so
it's very possible that I am out in left field. That's why I'm
asking questions, rather than making statements.