Researchers Using Hubble and Keck Telescopes Find Farthest Known Galaxy in the Universe

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:LPa_b.10392$4K3.5629@fed1read06...
Now, maybe you meant something other than 'density', but that's what you
said.


Do you agree that in terms of the solar spectrum it is not actually density
that you are referring to?

I refer to the density of the entire Universe, at two different times.
The
instant of emission occured in a Universe with a mass M_u, and a size R_u.
Absorption occured in a Universe that is likely close to M_u, but R_u is
now larger. So the "time base" for the absorbing Universe is short,
compared to the "time base" at emission.

I think you are actually talking about is gravitational potential.

It is clear that all changes in relativistic frame of reference involves an
transformation that is expressable as an energy shift/red shift. So
transformation from one frame to a moving frame requires addition of
kinetic energy that is equivalent to the classical Doppler red shift.

The URL you pointed to showed a red shift arising as a consequence of the
movement between two frameworks at different gravitational potentials. In
this case, the energy requirement is measured as the well known
gravitational red shift.


I do not find any web sites that have my "unique" interpretation of red
shift. This one is always good:
URL:http://www.astro.ucla.edu/~wright/cosmo_02.htm. Anyway, think Shapiro
time delay, if you are concerned about light passing through empty space.

Is it possible you have a circular argument here?
I think you say that the red shift is NOT due to speed of recession, however
it IS due to the fact that we were closer together in the past. How do you
square the 'closer together in the past' without having us currently moving
apart (and hence giving a 'recession based' red shift)?


I will only offer that we are moving at 200-300 km/sec wrt the Universe at
large, and likely have done so since we were embedded in the CMBR. If
"rushing away" from the ancient Universe is the correct terminology, then
we do so along the time axis. I just don't think "rushing away" is the
right terminology, which is why I was bitching. It has the baggage of
describing "where did the energy come from" to make us "rush away", faster
and faster.
Are you OK with "rushing away" to describe the red shift? Maybe I'm just
being too critical...

Too late to think about this - I'll get back to you tomorrow.

Dear OG:

"OG" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:LPa_b.10392$4K3.5629@fed1read06...
Now, maybe you meant something other than 'density', but that's what
you
said.

Do you agree that in terms of the solar spectrum it is not actually
density
that you are referring to?

The spectrum is indicative of the material emitting it, with the broadening
brought about by pressure. The difference in the Earth-detected spectrum
as compared to one "physically similar" to one here on the Earth, is as you
point out, due to the gravitational potential.

I refer to the density of the entire Universe, at two different times.
The
instant of emission occured in a Universe with a mass M_u, and a size
R_u.
Absorption occured in a Universe that is likely close to M_u, but R_u
is
now larger. So the "time base" for the absorbing Universe is short,
compared to the "time base" at emission.

I think you are actually talking about is gravitational potential.

Yes.

It is clear that all changes in relativistic frame of reference involves
an
transformation that is expressable as an energy shift/red shift.

Right.

So
transformation from one frame to a moving frame requires addition of
kinetic energy that is equivalent to the classical Doppler red shift.

I don't follow how "gravitational potential" equates to "kinetic energy" in
the sense that light appears redshifted when climbing out of a well.

The URL you pointed to showed a red shift arising as a consequence of the
movement between two frameworks at different gravitational potentials. In
this case, the energy requirement is measured as the well known
gravitational red shift.

And such redshifting is NOT (entirely) due to the motion of the source
and/or emitter. It is due to WHEN the light was emitted, and WHEN it was
received. In other words it is due to the "local" gravitational potentials
of the two versions of this Universe.

I do not find any web sites that have my "unique" interpretation of red
shift. This one is always good:
URL:http://www.astro.ucla.edu/~wright/cosmo_02.htm. Anyway, think
Shapiro
time delay, if you are concerned about light passing through empty
space.

Is it possible you have a circular argument here?

I wouldn't be at all surprised.

I think you say that the red shift is NOT due to speed of recession,

Right.

however
it IS due to the fact that we were closer together in the past.

Our velocity has not changed. The source's velocity has not changed. Yet
we even say that expansion is "accelerating". What is changing? Easily we
can say the slope of the "gravitational potential well" is changing,
between *then* and *now*.

Saying that we were "closer together" in the past... our velocity in a
small closed Universe is not moving away from *anything*, since the a**hole
ahead of us is... us. Expansion is not *motion*, is not kinetic, does not
involve transfer of energy. What magical force is it that maintains all
matter no matter (;}) where located *at a given distance from us* at a
proportional recession rate?

How do you
square the 'closer together in the past' without having us currently
moving
apart (and hence giving a 'recession based' red shift)?

I square it with not requiring the transmission of momentum.

The meter is currently defined as c and time. If c is constant (and it is
to more than one order of magnitude less than the Hubble parameter), then
something happens to time.

Altering the gravitational potential alters the rate that time passes, as
observed from someplace else. So if light is emitted from someplace with a
high slope to the "gravitational potential well", and absorbed in someplace
with a lower slope, the light will be received red shifted. The past and
the present have such a relationship.

I will only offer that we are moving at 200-300 km/sec wrt the Universe
at
large, and likely have done so since we were embedded in the CMBR. If
"rushing away" from the ancient Universe is the correct terminology,
then
we do so along the time axis. I just don't think "rushing away" is the
right terminology, which is why I was bitching. It has the baggage of
describing "where did the energy come from" to make us "rush away",
faster
and faster.
Are you OK with "rushing away" to describe the red shift? Maybe I'm
just
being too critical...

Too late to think about this - I'll get back to you tomorrow.

Yes. I wear me out too, sometimes.

Be sure and question the relationship between redshifting and subtended
angle (as far as that can take us)...

David A. Smith

Hi Dave,
So
transformation from one frame to a moving frame requires addition of
kinetic energy that is equivalent to the classical Doppler red shift.

I don't follow how "gravitational potential" equates to "kinetic energy"
in
the sense that light appears redshifted when climbing out of a well.

Ah, in this sentence I was thinking about the red shift coming from velocity
changes.

The URL you pointed to showed a red shift arising as a consequence of
the
movement between two frameworks at different gravitational potentials.
In
this case, the energy requirement is measured as the well known
gravitational red shift.

And such redshifting is NOT (entirely) due to the motion of the source
and/or emitter. It is due to WHEN the light was emitted, and WHEN it was
received. In other words it is due to the "local" gravitational
potentials
of the two versions of this Universe.

I have to agree for red shifts arising from lifting out of a graviational
well. - I'm not sure how well it works across the age/size of the universe.

snip

Our velocity has not changed. The source's velocity has not changed. Yet
we even say that expansion is "accelerating". What is changing? Easily
we
can say the slope of the "gravitational potential well" is changing,
between *then* and *now*.

Well (ignoring the proposed acceleration required to explain the SN1A
measurements), won't there have been a change in velocity, due to the
'slowing down of expansion' as the universe aged? The initial kinetic energy
of the small young universe has converted into gravitational potential
energy as the large old universe now.
The classic interpretation of Hubble's constant is that it is the inverse of
the age of the universe. This
implies that when the universe was younger, the value of H must have been
higher giving faster speeds in the past.*

Although speculative it seems intuitive to me that the change in
gravitational potential energy between 'then' and 'now' is identical to the
reduced delta vee between 'us then' and 'us now'. Surely conservation of
energy demands no less.

Saying that we were "closer together" in the past... our velocity in a
small closed Universe is not moving away from *anything*, since the
a**hole
ahead of us is... us. Expansion is not *motion*, is not kinetic, does not
involve transfer of energy. What magical force is it that maintains all
matter no matter (;}) where located *at a given distance from us* at a
proportional recession rate?

Expansion against the general gravitational pull of the universe is enough
to give the expansion seen. There IS a transfer of energy (from Potential to
Kinetic).

How do you
square the 'closer together in the past' without having us currently
moving
apart (and hence giving a 'recession based' red shift)?

I square it with not requiring the transmission of momentum.

You've lost me here I'm afraid.

The meter is currently defined as c and time. If c is constant (and it is
to more than one order of magnitude less than the Hubble parameter), then
something happens to time.

Only if you assume that something has happened to the metre since then.
There's no evidence for this.

Altering the gravitational potential alters the rate that time passes, as
observed from someplace else. So if light is emitted from someplace with
a
high slope to the "gravitational potential well", and absorbed in
someplace
with a lower slope, the light will be received red shifted. The past and
the present have such a relationship.

I think I would want to see a complete cosmological treatment before I
accepted this.

snip

Be sure and question the relationship between redshifting and subtended
angle (as far as that can take us)...

Eh? I've not seen anything to make me question this relationship. Should I
be aware of something?

Cheers
Owen

On Mon, 23 Feb 2004 04:22:01 +0000, CeeBee wrote:

"OG" wrote in alt.astronomy:


DO YOU MIND I was talking about something else.

You simply can't cope with Bert's brilliance. We understand.

Rofl!