Universal "ether" time?

James A. Donald kirjutas:
On 17 May 2007 12:18:38 -0700,
wrote:
Where is the zero point of the speed of time?

Anywhere you choose it. If you are worried about
relativistic effects of planetary motion, a good place
to station your reference clock would be in orbit a
sufficient distance from the sun.

Do clocks run with different speed at different
latitudes (according to how fast Earth rotates with
them)?

Yes.

Does the speed of clock differ between night (when
Earth rotates in direction of orbit) and day (when the
rotation is against orbit)?

Depends on your reference clock. If your reference
clock is moving with the earth, then no. Whether the
earth clocks go faster or slower depends on how they are
moving relative to the reference clock.

are there any seasonal changes due to Earth orbiting
faster and slower?

Depends on your reference clock. If it is floating in
an orbit sufficiently far from the sun that we can
consider it to be near enough stationary, then yes.

Due to being deeper in the gravity potential well of
Sun and shallower again?

Yes. Being deeper in the gravity well slows down time,
and being faster also slows down time, so clocks in
orbits near the sun run slow relative to clocks in
orbits further out.

What about orbital movement being sometimes towards
and sometimes against the movement of Sun?

This only matters if your reference clock is not moving
with the sun. Now, instead of placing it in distant
orbit around the sun, place it in distant orbit around
the galaxy. Then the movement of the sun matters.

How much is speed of clocks on Earth slowed by the
gravity well of Milky Way and crown? How big is the
actual gravity well of Milky Way?

I seem to recollect the gravity well is something around
100000 km2sec-2, not sure,.

Is any one sure?

After all, if we look at a distant galaxy, the spectral shift is a
combination of:

1) redshift of light when leaving the gravity well of the distant
galaxy

2) red or sometimes blue shift due to real movement of that galaxy
relative to Milky Way

3) blue shift of the light when entering the gravity well of Milky
Way.

Do we have any clue about what 3) might be?

If so, the gravitational
slowing of time due the galaxy is something around one
part in a million.

Where can the zero point of gravitational potential be
found?

Anywhere you choose.

On 22 May 2007 08:17:24 -0700, wrote:


James A. Donald kirjutas:
On 17 May 2007 12:18:38 -0700,
snip

How much is speed of clocks on Earth slowed by the
gravity well of Milky Way and crown? How big is the
actual gravity well of Milky Way?

I seem to recollect the gravity well is something around
100000 km2sec-2, not sure,.

Is any one sure?

After all, if we look at a distant galaxy, the spectral shift is a
combination of:

1) redshift of light when leaving the gravity well of the distant
galaxy

2) red or sometimes blue shift due to real movement of that galaxy
relative to Milky Way

3) blue shift of the light when entering the gravity well of Milky
Way.

If so, the gravitational
s
Do we have any clue about what 3) might be?
snip
There's a blue shift of 635 m/s at Sol's surface, and of 0.208 m/s at
Earth's surface. Divide by c.
John Polasek

wrote in message
ups.com...
....
3) blue shift of the light when entering the gravity well of Milky
Way.

Do we have any clue about what 3) might be?

We can measure the speeds of stars and gas clouds
as they orbit the galaxy. That gives an estimate
of the mass of the galaxy and its distribution. We
can measure how far we are from the centre so that
tells us how far into the well we lie. The blue
shift, and the coordinate rate of clocks relative
to an equivalent clock in inter-galactic space
follow from those.

George

John C. Polasek wrote:

There's a blue shift of 635 m/s at Sol's surface, and of 0.208 m/s at
Earth's surface. Divide by c.

Blueshift is a measurement of a change in frequency. A blueshift
expressed as a speed doesn't make much sense.


--
Erik Max Francis && && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM, Y!M erikmaxfrancis
Gods are born and die, but the atom endures.
-- Alexander Chase, 1966

wrote:

Is any one sure?

After all, if we look at a distant galaxy, the spectral shift is a
combination of:

1) redshift of light when leaving the gravity well of the distant
galaxy

2) red or sometimes blue shift due to real movement of that galaxy
relative to Milky Way

3) blue shift of the light when entering the gravity well of Milky
Way.

You're also missing 4. extinction (reddening) due to gas and dust, and
5. redshift due to cosmological expansion.

Do we have any clue about what 3) might be?

Sure; very little. To first order, gravitational redshift z for a
photon starting at a distance r from a mass m and escaping to infinity is

z = (G m)/(c^2 r).

Thus, this would be the _blue_shift from a photon travelling from
infinity to a distance r from a mass m.

For our Galaxy and our location in our Galaxy, m = 2 x 10^42 kg, r = 3 x
10^20 m, so z = 5 x 10^-6. This is an utterly negligible redshift, as z
is defined as

z = delta lambda/lambda

It means that the gravitational redshift would change wavelengths by
about five parts per million. We can't usually measure wavelengths of
photons that accurately anyway, so it's an important redshift.

This also applies to your case 1, which is just the time reverse of the
same process. What controls redshifts from intergalactic objects is
peculiar motions (2) for nearby objects, and extinction and cosmological
redshift (4, 5) for distant objects. Gravitational redshift is only
significant if you're talking about a photon coming from very near a
very massive object indeed, such as a galactic black hole, and
gravitational blueshift is only significant if you're very near one of
those massive objects yourself, in which case you've probably got bigger
problems than observing distant galaxies.

--
Erik Max Francis && && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM, Y!M erikmaxfrancis
Gods are born and die, but the atom endures.
-- Alexander Chase, 1966

Erik Max Francis wrote:

It means that the gravitational redshift would change wavelengths by
about five parts per million. We can't usually measure wavelengths of
photons that accurately anyway, so it's an important redshift.

.... I meant "unimportant," of course.

--
Erik Max Francis && && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM, Y!M erikmaxfrancis
Once the people begin to reason, all is lost.
-- Voltaire

On Tue, 22 May 2007 13:43:19 -0700, Erik Max Francis
wrote:

John C. Polasek wrote:

There's a blue shift of 635 m/s at Sol's surface, and of 0.208 m/s at
Earth's surface. Divide by c.

Blueshift is a measurement of a change in frequency. A blueshift
expressed as a speed doesn't make much sense.

Actually redshift and blueshift are changes in wavelength not
frequency. 635m/s/c is fractional increase in velocity of light and
thus, lambda, from Sol's surface, Conversely it is the decrease in
lambda for light reaching the sun, a blue shift. My equation for this
is dc^2/2/dr = cdc/dr = MG/r^2.
It defines how c accelerates away when leaving M.
The reduced frequency after emission is not affected whatsoever by
gravity, only the clock radiator is.
John Polasek

John C. Polasek wrote:

Actually redshift and blueshift are changes in wavelength not
frequency.

Whether you express it as a change in frequency or wavelength is a
matter of taste, although admittedly wavelength is more common.
Frequency nu and wavelength lambda re related by lambda nu = c.

635m/s/c is fractional increase in velocity of light and
thus, lambda, from Sol's surface, Conversely it is the decrease in
lambda for light reaching the sun, a blue shift.

Except that gravitational redshift has nothing to do with a change in
the speed of light. The speed of light is always constant locally, so
your approach is completely wrong.

Wavelength, lambda, is measured in units of distance. Change in
wavelength, delta lambda, is also measured in units of distance. The
redshift parameter, defined as z = delta lambda/lambda, is a distance
divided by a distance.

If one prefers to talk about frequencies instead of wavelengths, then
frequency nu is in inverse units of time. Change in frequency, delta
nu, is also in inverse units of time. The redshift parameter is thus

z = delta lambda/lambda = (c/delta nu)/(c/nu) = nu/delta nu,

which is also, of course, dimensionless. None of these terms has units
of speed at all.

My equation for this
is dc^2/2/dr = cdc/dr = MG/r^2.
It defines how c accelerates away when leaving M.

c does not "accelerate," so I don't know where you're getting that
equation. Wavelength changes, not the speed of light. The
gravitational redshift equation is (to first order)

z = (G m)/(c^2 r).

--
Erik Max Francis && && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM, Y!M erikmaxfrancis
The core of our defense is the faith we have in the institutions we
defend. -- Franklin D. Roosevelt, 1940

On Tue, 22 May 2007 18:02:41 -0700, Erik Max Francis
wrote:

John C. Polasek wrote:

Actually redshift and blueshift are changes in wavelength not
frequency.

snip.

635m/s/c is fractional increase in velocity of light and
thus, lambda, from Sol's surface, Conversely it is the decrease in
lambda for light reaching the sun, a blue shift.

snip
Excuse me if I feel compelled to excise your puerile and verbose
primer regarding wavelength and frequency. I am well acquainted with
the principles, as are others.
Both Pound/Rebka and also Brault proved that there was gravitational
redshift and measured it, as well as they could. There is a lot of
poppycock about gravitational redshift. I have shown how it works in
another thread " Relativity hypnotists explain the Pound Rebka
experiment." sci.physics.relativity 5/18/2007 4:56PM.
There I have reduced the whole Pound Rebka experiment to a simple
table that explains my equation. You are free to insert your own
numbers and present them for review. The fact is, you don't know what
causes gravitational redshift.
My equation for this
is dc^2/2/dr = cdc/dr = MG/r^2.
It defines how c accelerates away when leaving M.

c does not "accelerate," so I don't know where you're getting that
equation. Wavelength changes, not the speed of light.
Right: E = h*nu, the energy is unaffected by gravity. The wavelength
stretches on the way up at cdc/dr. The frequency started low in the
well and stayed that way.
The
gravitational redshift equation is (to first order)

z = (G m)/(c^2 r).
So tell me how it works.
John Polasek.

: John C. Polasek
: The fact is, you don't know what causes gravitational redshift.

Gravity.

So, you are another of the multitude that conclude Einstein
got it all wrong, and the speed of light isn't invariant after all?
Just to be clear what position you're staking out.


Wayne Throop http://sheol.org/throopw