How can galaxies move FTL relative to each other?

Hello,

If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light. Simliarly,
soon after the Big Bang, objects moved faster than light. (In both
cases, I'm relying on memory.)

You can tell me that the sources I've read are worthless. Fine. You
can tell me I've remembered wrong. Fine.

But if I'm correct, how can these be?

The explanations I've read go something like this:
1. "The speed-of-light rule doesn't apply at quantum sizes, such as
were in play during the first moments after the Big Bang."
(Why not? And does that mean that subatomic objects can move
FTL?)
2. The speed-of-light rule doesn't apply at vast distances, such as
the distances between galaxies."
(Why not? At which distances does the speed rule become moot?)
3. The speed-of-light rule applies, and it is not violated. The
objects aren't really moving FTL. Instead, the space containing them
is explanding FTL.
(Oh really? How can we tell the difference between "two objects
moving relative to each other" and "space expanding or contracting
between two objects"?)

This is a serious, if naive, question. Thank you for all serious
answers.

Ted Shoemaker

"Ted Shoemaker" wrote in message
...
| Hello,
|
| If I read correctly, galaxies are generally moving away from each
| other, sometimes at speeds greater than that of light. Simliarly,
| soon after the Big Bang, objects moved faster than light. (In both
| cases, I'm relying on memory.)
|
| You can tell me that the sources I've read are worthless. Fine. You
| can tell me I've remembered wrong. Fine.

Ok, done.

On Oct 20, 1:20*pm, Ted Shoemaker wrote:
Hello,

If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light. *Simliarly,
soon after the Big Bang, objects moved faster than light. *(In both
cases, I'm relying on memory.)

You can tell me that the sources I've read are worthless. *Fine. *You
can tell me I've remembered wrong. *Fine.

But if I'm correct, how can these be?

The explanations I've read go something like this:
1. *"The speed-of-light rule doesn't apply at quantum sizes, such as
were in play during the first moments after the Big Bang."
* * *(Why not? *And does that mean that subatomic objects can move
FTL?)
2. *The speed-of-light rule doesn't apply at vast distances, such as
the distances between galaxies."
* * *(Why not? *At which distances does the speed rule become moot?)
3. *The speed-of-light rule applies, and it is not violated. *The
objects aren't really moving FTL. *Instead, the space containing them
is explanding FTL.
* * *(Oh really? *How can we tell the difference between "two objects
moving relative to each other" and "space expanding or contracting
between two objects"?)

This is a serious, if naive, question. *Thank you for all serious
answers.

Ted Shoemaker

0.5 c is as fast as anything physical can be forced to move.

Perhaps the voodoo physics of SR/GR makes it only seem as though
greater velocity is possible. However, the force of gravity and
gravity lensing should be faster than light.

~ BG

"Androcles" wrote in message
...

"Ted Shoemaker" wrote in message
...
| Hello,
|
| If I read correctly, galaxies are generally moving away from each
| other, sometimes at speeds greater than that of light. Simliarly,
| soon after the Big Bang, objects moved faster than light. (In both
| cases, I'm relying on memory.)
|
| You can tell me that the sources I've read are worthless. Fine. You
| can tell me I've remembered wrong. Fine.

Ok, done.


So, someone raises some very valid points and that's your contribution ???

On Oct 20, 3:20*pm, Ted Shoemaker wrote:
Hello,

If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light. *Simliarly,
soon after the Big Bang, objects moved faster than light. *(In both
cases, I'm relying on memory.)

You can tell me that the sources I've read are worthless. *Fine. *You
can tell me I've remembered wrong. *Fine.

But if I'm correct, how can these be?

The explanations I've read go something like this:
1. *"The speed-of-light rule doesn't apply at quantum sizes, such as
were in play during the first moments after the Big Bang."
* * *(Why not? *And does that mean that subatomic objects can move
FTL?)
2. *The speed-of-light rule doesn't apply at vast distances, such as
the distances between galaxies."
* * *(Why not? *At which distances does the speed rule become moot?)
3. *The speed-of-light rule applies, and it is not violated. *The
objects aren't really moving FTL. *Instead, the space containing them
is explanding FTL.
* * *(Oh really? *How can we tell the difference between "two objects
moving relative to each other" and "space expanding or contracting
between two objects"?)

This is a serious, if naive, question. *Thank you for all serious
answers.

Ted Shoemaker

There is no such thing as speed of light unless you are comparing the
state of
one object to another.

So to say the galaxies are fleeing from one another greater than the
speed of light
is a vague, meaningless statement, since you are not comparing the
state of one object
to another, but to a whole fleet of obects.

On Oct 20, 5:39*pm, Mark Earnest wrote:
On Oct 20, 3:20*pm, Ted Shoemaker wrote:





Hello,

If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light. *Simliarly,
soon after the Big Bang, objects moved faster than light. *(In both
cases, I'm relying on memory.)

You can tell me that the sources I've read are worthless. *Fine. *You
can tell me I've remembered wrong. *Fine.

But if I'm correct, how can these be?

The explanations I've read go something like this:
1. *"The speed-of-light rule doesn't apply at quantum sizes, such as
were in play during the first moments after the Big Bang."
* * *(Why not? *And does that mean that subatomic objects can move
FTL?)
2. *The speed-of-light rule doesn't apply at vast distances, such as
the distances between galaxies."
* * *(Why not? *At which distances does the speed rule become moot?)
3. *The speed-of-light rule applies, and it is not violated. *The
objects aren't really moving FTL. *Instead, the space containing them
is explanding FTL.
* * *(Oh really? *How can we tell the difference between "two objects
moving relative to each other" and "space expanding or contracting
between two objects"?)

This is a serious, if naive, question. *Thank you for all serious
answers.

Ted Shoemaker

There is no such thing as speed of light unless you are comparing the
state of
one object to another.

So to say the galaxies are fleeing from one another greater than the
speed of light
is a vague, meaningless statement, since you are not comparing the
state of one object
to another, but to a whole fleet of obects.- Hide quoted text -

- Show quoted text -

You can scan the Milky Way in one second. How much faster than light
is that? TreBert

(Ted Shoemaker) wrote:
If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light.

Relative to each other, sure. If you and I are each driving 55mph in
exactly opposite directions toward one another, and we collide head-on,
each of us feels a 110mph (55+55) impact _in our frame of reference_.

By the same logic, if we are each driving 500mph (jet-powered cars)
in exactly opposite directions _away from_ one another, the combined
velocity as seen in either of our frames of reference is 1,000mph -
so while we'd still be able to see each other receding in the distance,
we wouldn't be able to _hear_ each other, because the combined velocity
is greater than the speed of sound, so sound you emit can't reach me.

So if you have two galaxies moving away from each other with a combined
velocity greater than the speed of light, light one emits can't reach
the other. Not very difficult.

Simliarly, soon after the Big Bang, objects moved faster than light.
(In both cases, I'm relying on memory.)

I haven't heard this, so I won't try to explain it.

-Dan

--
djb@ | Dan Birchall - Observation System Associate - Subaru Telescope.
naoj | Views I express are my own, obviously not those of my employer.
..org | Our atmospheric inversion layer keeps silly people below 3000m.

"Dan Birchall" wrote in message
...
| (Ted Shoemaker) wrote:
| If I read correctly, galaxies are generally moving away from each
| other, sometimes at speeds greater than that of light.
|
| Relative to each other, sure. If you and I are each driving 55mph in
| exactly opposite directions toward one another, and we collide head-on,
| each of us feels a 110mph (55+55) impact _in our frame of reference_.
|
| By the same logic, if we are each driving 500mph (jet-powered cars)
| in exactly opposite directions _away from_ one another, the combined
| velocity as seen in either of our frames of reference is 1,000mph -
| so while we'd still be able to see each other receding in the distance,
| we wouldn't be able to _hear_ each other, because the combined velocity
| is greater than the speed of sound, so sound you emit can't reach me.
|
| So if you have two galaxies moving away from each other with a combined
| velocity greater than the speed of light, light one emits can't reach
| the other. Not very difficult.
|
| Simliarly, soon after the Big Bang, objects moved faster than light.
| (In both cases, I'm relying on memory.)
|
| I haven't heard this, so I won't try to explain it.
|
| -Dan
By the same logic, a car travelling at 60 mph that leaves an hour later
it will pass a car travelling at 50 mph after 300 miles.
So if you have a star moving in an elliptical orbit at just the right
distance
it will appear to go nova as all the light enters your telescope at the same
time.
Not very difficult.
http://www.androcles01.pwp.blueyonder.co.uk/Doolin'sStar.GIF
Real data:
http://www.britastro.org/vss/gifc/00918-ck.gif

On Oct 20, 5:00*pm, bert wrote:
On Oct 20, 5:39*pm, Mark Earnest wrote:



On Oct 20, 3:20*pm, Ted Shoemaker wrote:

Hello,

If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light. *Simliarly,
soon after the Big Bang, objects moved faster than light. *(In both
cases, I'm relying on memory.)

You can tell me that the sources I've read are worthless. *Fine. *You
can tell me I've remembered wrong. *Fine.

But if I'm correct, how can these be?

The explanations I've read go something like this:
1. *"The speed-of-light rule doesn't apply at quantum sizes, such as
were in play during the first moments after the Big Bang."
* * *(Why not? *And does that mean that subatomic objects can move
FTL?)
2. *The speed-of-light rule doesn't apply at vast distances, such as
the distances between galaxies."
* * *(Why not? *At which distances does the speed rule become moot?)
3. *The speed-of-light rule applies, and it is not violated. *The
objects aren't really moving FTL. *Instead, the space containing them
is explanding FTL.
* * *(Oh really? *How can we tell the difference between "two objects
moving relative to each other" and "space expanding or contracting
between two objects"?)

This is a serious, if naive, question. *Thank you for all serious
answers.

Ted Shoemaker

There is no such thing as speed of light unless you are comparing the
state of
one object to another.

So to say the galaxies are fleeing from one another greater than the
speed of light
is a vague, meaningless statement, since you are not comparing the
state of one object
to another, but to a whole fleet of obects.- Hide quoted text -

- Show quoted text -

You can scan the Milky Way in one second. How much faster than light
is that? * TreBert

Good one, but not quite the same thing.

~ BG

On Oct 20, 7:00*pm, bert wrote:
On Oct 20, 5:39*pm, Mark Earnest wrote:





On Oct 20, 3:20*pm, Ted Shoemaker wrote:

Hello,

If I read correctly, galaxies are generally moving away from each
other, sometimes at speeds greater than that of light. *Simliarly,
soon after the Big Bang, objects moved faster than light. *(In both
cases, I'm relying on memory.)

You can tell me that the sources I've read are worthless. *Fine. *You
can tell me I've remembered wrong. *Fine.

But if I'm correct, how can these be?

The explanations I've read go something like this:
1. *"The speed-of-light rule doesn't apply at quantum sizes, such as
were in play during the first moments after the Big Bang."
* * *(Why not? *And does that mean that subatomic objects can move
FTL?)
2. *The speed-of-light rule doesn't apply at vast distances, such as
the distances between galaxies."
* * *(Why not? *At which distances does the speed rule become moot?)
3. *The speed-of-light rule applies, and it is not violated. *The
objects aren't really moving FTL. *Instead, the space containing them
is explanding FTL.
* * *(Oh really? *How can we tell the difference between "two objects
moving relative to each other" and "space expanding or contracting
between two objects"?)

This is a serious, if naive, question. *Thank you for all serious
answers.

Ted Shoemaker

There is no such thing as speed of light unless you are comparing the
state of
one object to another.

So to say the galaxies are fleeing from one another greater than the
speed of light
is a vague, meaningless statement, since you are not comparing the
state of one object
to another, but to a whole fleet of obects.- Hide quoted text -

- Show quoted text -

You can scan the Milky Way in one second. How much faster than light
is that? * TreBert- Hide quoted text -

- Show quoted text -

If you assume that you can touch a star just by looking at it, which
is
feasible if you consider the spirits of things, then sure, your line
of vision exceeds
the speed of light all the time when looking up at the night time sky
on any clear night.