Sam Wormley wrote:
I don't think this answers the question.
This is just 2 equations to describe how a wavelength shift can be related
to two different causes.

Question .. how can we distinguish a red shift due to a moving object from a
red shift due to a gravitational field.

md wrote:
relativity predicts a red-shift for light traveling "up" in a gravity
field. Doppler predicts a red-shift for light emitted from an object
moving away from us.

How can we distinguish the two? When we measure the red-shift of a
distant object, how can we conclude that it moves away from us? It might
also be that it is not moving away, but it is very heavy instead?


Relativistic Redshift
http://scienceworld.wolfram.com/phys...cRedshift.html

Gravitational Redshift
http://scienceworld.wolfram.com/phys...lRedshift.html

Doppler Effect
http://scienceworld.wolfram.com/phys...lerEffect.html

These three sources of redshift can usually be sorted by the context
of other data made in the measurement process.

md wrote:
relativity predicts a red-shift for light traveling "up" in a gravity field.
Doppler predicts a red-shift for light emitted from an object moving away from us.

How can we distinguish the two? When we measure the red-shift of a distant object, how can we
conclude that it moves away from us? It might also be that it is not moving away, but it is
very heavy instead?


Relativistic Redshift
http://scienceworld.wolfram.com/phys...cRedshift.html

Gravitational Redshift
http://scienceworld.wolfram.com/phys...lRedshift.html

Doppler Effect
http://scienceworld.wolfram.com/phys...lerEffect.html

These three sources of redshift can usually be sorted by the context
of other data made in the measurement process.

"Sam Wormley" wrote in message news:exPPd.66163$EG1.51167@attbi_s53...
md wrote:
relativity predicts a red-shift for light traveling "up" in a gravity field.
Doppler predicts a red-shift for light emitted from an object moving away from us.

How can we distinguish the two? When we measure the red-shift of a distant object, how can
we
conclude that it moves away from us? It might also be that it is not moving away, but it is
very heavy instead?


Relativistic Redshift
http://scienceworld.wolfram.com/phys...cRedshift.html

Gravitational Redshift
http://scienceworld.wolfram.com/phys...lRedshift.html

Doppler Effect
http://scienceworld.wolfram.com/phys...lerEffect.html

thanks for the formulae, but they did not really answer my question.

These three sources of redshift can usually be sorted by the context
of other data made in the measurement process.

how?
--
md
10" LX200GPS-SMT
ETX105
www.xs4all.nl/~martlian

One way is to take the measurements in a binary system. From the spectral type
of the component stars, an estimate of their distance, and their orbital period,
all measurable through telescopes and some inferring, you can get the pairs
motion around each other and through space, at least in the line of sight. From
this you can eliminate causes of red shift due to motion, eliminate them, and
uncover other red shift effects.

This was, in fact, how gravitationally induced red shift was measured for the
first time, using the white dwarf companion of Sirius, I believe, if not the one
around Procyon, but I believe it was Sirius. The period, mass, and the pair's
mutual motion through space are measurable or can be calculated from the
observed. From this, all red shifts due to motion can be eliminated. Then
because the companion has a high surface gravity, it can produce a gravitational
red shift, which was what was left when the other causes were eliminated, and it
matched what Einstein predicted for the mass of the companion.
--
Sincerely,
--- Dave
----------------------------------------------------------------------
It don't mean a thing
unless it has that certain "je ne sais quoi"
Duke Ellington
----------------------------------------------------------------------

"md" not given to avoid spam wrote in message
...

"Sam Wormley" wrote in message
news:exPPd.66163$EG1.51167@attbi_s53...
md wrote:
relativity predicts a red-shift for light traveling "up" in a gravity
field.
Doppler predicts a red-shift for light emitted from an object moving away
from us.

How can we distinguish the two? When we measure the red-shift of a distant
object, how can
we
conclude that it moves away from us? It might also be that it is not moving
away, but it is
very heavy instead?


Relativistic Redshift
http://scienceworld.wolfram.com/phys...cRedshift.html

Gravitational Redshift
http://scienceworld.wolfram.com/phys...lRedshift.html

Doppler Effect
http://scienceworld.wolfram.com/phys...lerEffect.html

thanks for the formulae, but they did not really answer my question.

These three sources of redshift can usually be sorted by the context
of other data made in the measurement process.

how?
--
md
10" LX200GPS-SMT
ETX105
www.xs4all.nl/~martlian

On Mon, 14 Feb 2005 05:08:56 GMT, "David Nakamoto"
wrote:

One way is to take the measurements in a binary system. From the spectral type
of the component stars, an estimate of their distance, and their orbital period,
all measurable through telescopes and some inferring, you can get the pairs
motion around each other and through space, at least in the line of sight. From
this you can eliminate causes of red shift due to motion, eliminate them, and
uncover other red shift effects.

This was, in fact, how gravitationally induced red shift was measured for the
first time, using the white dwarf companion of Sirius, I believe, if not the one
around Procyon, but I believe it was Sirius. The period, mass, and the pair's
mutual motion through space are measurable or can be calculated from the
observed. From this, all red shifts due to motion can be eliminated. Then
because the companion has a high surface gravity, it can produce a gravitational
red shift, which was what was left when the other causes were eliminated, and it
matched what Einstein predicted for the mass of the companion.
Gravity can be ruled out pretty much because it is a feeble effect.
The sun has pretty good gravity 27G but the gravity redshift z = 635/c
= 0.0000021.
A galaxy with this shift would have Doppler velocity of 635km/second
which is very small cosmologically, well, 0.0000021 of c. The distance
computed using Hubble's constant would be 30,000 LY which is only
about 1 2 millionth of the radius of the universe (13BLY).
Mr. Dual Space

If you have something to say, write an equation.
If you have nothing to say, write an essay

"John C. Polasek" wrote in message
...
On Mon, 14 Feb 2005 05:08:56 GMT, "David Nakamoto"
wrote:

One way is to take the measurements in a binary system. From the spectral type
of the component stars, an estimate of their distance, and their orbital period,
all measurable through telescopes and some inferring, you can get the pairs
motion around each other and through space, at least in the line of sight. From
this you can eliminate causes of red shift due to motion, eliminate them, and
uncover other red shift effects.

This was, in fact, how gravitationally induced red shift was measured for the
first time, using the white dwarf companion of Sirius, I believe, if not the one
around Procyon, but I believe it was Sirius. The period, mass, and the pair's
mutual motion through space are measurable or can be calculated from the
observed. From this, all red shifts due to motion can be eliminated. Then
because the companion has a high surface gravity, it can produce a gravitational
red shift, which was what was left when the other causes were eliminated, and it
matched what Einstein predicted for the mass of the companion.

Gravity can be ruled out pretty much because it is a feeble effect.

it would solve some dark matter issues :-) perhaps we have it all wrong and are those galaxies
much heavier than we thought ;-)

John C. Polasek wrote:
On Mon, 14 Feb 2005 05:08:56 GMT, "David Nakamoto"
wrote:


One way is to take the measurements in a binary system. From the spectral type
of the component stars, an estimate of their distance, and their orbital period,
all measurable through telescopes and some inferring, you can get the pairs
motion around each other and through space, at least in the line of sight. From
this you can eliminate causes of red shift due to motion, eliminate them, and
uncover other red shift effects.

This was, in fact, how gravitationally induced red shift was measured for the
first time, using the white dwarf companion of Sirius, I believe, if not the one
around Procyon, but I believe it was Sirius. The period, mass, and the pair's
mutual motion through space are measurable or can be calculated from the
observed. From this, all red shifts due to motion can be eliminated. Then
because the companion has a high surface gravity, it can produce a gravitational
red shift, which was what was left when the other causes were eliminated, and it
matched what Einstein predicted for the mass of the companion.

Gravity can be ruled out pretty much because it is a feeble effect.
The sun has pretty good gravity 27G but the gravity redshift z = 635/c
= 0.0000021.
A galaxy with this shift would have Doppler velocity of 635km/second
which is very small cosmologically, well, 0.0000021 of c. The distance
computed using Hubble's constant would be 30,000 LY which is only
about 1 2 millionth of the radius of the universe (13BLY).

What makes you think that the radius of the universe is 13 BLY?


Bye,
Bjoern

md wrote:
"John C. Polasek" wrote in message
...

On Mon, 14 Feb 2005 05:08:56 GMT, "David Nakamoto"
wrote:


One way is to take the measurements in a binary system. From the spectral type
of the component stars, an estimate of their distance, and their orbital period,
all measurable through telescopes and some inferring, you can get the pairs
motion around each other and through space, at least in the line of sight. From
this you can eliminate causes of red shift due to motion, eliminate them, and
uncover other red shift effects.

This was, in fact, how gravitationally induced red shift was measured for the
first time, using the white dwarf companion of Sirius, I believe, if not the one
around Procyon, but I believe it was Sirius. The period, mass, and the pair's
mutual motion through space are measurable or can be calculated from the
observed. From this, all red shifts due to motion can be eliminated. Then
because the companion has a high surface gravity, it can produce a gravitational
red shift, which was what was left when the other causes were eliminated, and it
matched what Einstein predicted for the mass of the companion.

Gravity can be ruled out pretty much because it is a feeble effect.


it would solve some dark matter issues :-) perhaps we have it all wrong and are those galaxies
much heavier than we thought ;-)

Err, that would not solve dark matter issues - that would make them
*bigger*. We can measure with methods independent of Hubble's law for
many galaxies how far away they are. Then we can, using the seen
brightness, estimate how much mass is there. And that visible mass is by
far not enough to account for the observed red shift. So, if the red
shift is due to the gravitation of the galaxy, there has to be a *huge*
amount of non-visible, i.e. dark matter in them!


Bye,
Bjoern

On Tue, 15 Feb 2005 10:05:38 +0100, Bjoern Feuerbacher
wrote:

John C. Polasek wrote:
On Mon, 14 Feb 2005 05:08:56 GMT, "David Nakamoto"
wrote:


One way is to take the measurements in a binary system. From the spectral type
of the component stars, an estimate of their distance, and their orbital period,
all measurable through telescopes and some inferring, you can get the pairs
motion around each other and through space, at least in the line of sight. From
this you can eliminate causes of red shift due to motion, eliminate them, and
uncover other red shift effects.

This was, in fact, how gravitationally induced red shift was measured for the
first time, using the white dwarf companion of Sirius, I believe, if not the one
around Procyon, but I believe it was Sirius. The period, mass, and the pair's
mutual motion through space are measurable or can be calculated from the
observed. From this, all red shifts due to motion can be eliminated. Then
because the companion has a high surface gravity, it can produce a gravitational
red shift, which was what was left when the other causes were eliminated, and it
matched what Einstein predicted for the mass of the companion.

Gravity can be ruled out pretty much because it is a feeble effect.
The sun has pretty good gravity 27G but the gravity redshift z = 635/c
= 0.0000021.
A galaxy with this shift would have Doppler velocity of 635km/second
which is very small cosmologically, well, 0.0000021 of c. The distance
computed using Hubble's constant would be 30,000 LY which is only
about 1 2 millionth of the radius of the universe (13BLY).

What makes you think that the radius of the universe is 13 BLY?


Bye,
Bjoern
13 BLY or 1.23x10^26 m is generally recognized as the radius of the
universe. It is the popularly accepted age in yrs x the speed of light
on the TIME axis. It is part of my Dual Space theory and a little
diagram explaining this can be seen at http://www.dualspace.net.
This same theory is also capable of explaining the Pioneer 10 anomaly
on which topic relativity remains mute.

But if you have another number for the radius, feel free to use it and
I think you will find the imputed galactic distance of 30,000 LY for
the Sun will still be an immeasurably low fraction thereof.
John Polasek

If you have something to say write an equation.
If you have nothing to say, write an essay.

On Tue, 15 Feb 2005 10:17:32 -0500, John C. Polasek
wrote:

13 BLY or 1.23x10^26 m is generally recognized as the radius of the
universe...

It is certainly not "generally" recognized as such. You've just defined
the part that is visible. Most cosmologists consider the Universe to be
a good deal larger than that, however.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com