Time dilation #2

On Apr 9, 10:33*pm, Tom Roberts wrote in
sci.physics.relativity:
bill wrote:
A person is located on a mountain top and is looking at a (very large)
clock (B) at sea-level.
He notices that clock B is ticking over at a slower rate than his own
clock (A) as theorized by Einstein in general theory and as ratified
by the Wallops Island experiment where a clock at sea-level, being
located in a strong gravitational tidal area, will tick over at a
slower rate than an identical clock on top of a mountain that is in a
weaker gravitational tidal area.

Note that what you call "gravitational tidal area" is really called
"Newtonian gravitational potential", valid in the Newtonian
approximation to GR. Indeed, tidal forces/effects are not involved
(tidal forces are second derivatives of the Newtonian potential).

Note that while A _SEES_ B tick at a slower rate, this does not imply
that clock B actually ticks at a slower rate than clock A. Indeed, in GR
this is modeled as an artifact of the COMPARISON [#], not as an effect
or modification of the clocks themselves: both clocks tick at their
usual (proper) rates, but their tick rates appear different when
situated and compared as you describe.

* * * * [#] This comparison is via EM signals in curved spacetime..

Is he entitled to be of the opinion that if he were to move to sea-
level his clock would be subjected to the same 'law' of physics thus
it will then be ticking over at a slower rate than it is before he
starts his descent?

No. See above -- this is not an effect ON THE CLOCKS, but rather OF THE
COMPARISON. Note that he is entitled to expect that if he carries his
clock down and puts it right next to B that the two clocks will tick at
the same rate.

Your statements are expressed with the implicit assumption there there
is some "global", "universal", or "absolute" way to determine a clock's
tick rate. In GR there is no such thing -- all you can do is compare
clocks to other clocks; the method of comparison can, and usually does,
affect the result.

Tom Roberts

Honest Roberts, your cleverer brothers Einsteinians expose the
"artifact of the COMPARISON" in a somewhat clearer way:

http://www.people.fas.harvard.edu/~djmorin/book.html
Chapter 14: "The equivalence principle has a striking consequence
concerning the behavior of clocks in a gravitational field. It implies
that higher clocks run faster than lower clocks. If you put a watch on
top of a tower, and then stand on the ground, you will see the watch
on the tower tick faster than an identical watch on your wrist. When
you take the watch down and compare it to the one on your wrist, it
will show more time elapsed."

However, Honest Roberts, even your cleverer brothers Einsteinians
would never answer the following question:

Is the "artifact of the COMPARISON" (that is, gravitational time
dilation) consistent with Einsteiniana's dicovery that the speed of
light is CONSTANT in a gravitational field, or is it consistent with
Einsteiniana's discovery that the speed of light is VARIABLE in a
gravitational field and obeys e.g. Einstein's 1911 equation c'=c(1+gh/
c^2) given by Newton's emission theory of light?

Pentcho Valev

On Apr 9, 11:26 pm, Pentcho Valev wrote:
c'=c(1+gh/c^2) given by Newton's emission theory of light?


The old fart Pentcho is back jacking off to his old idiocy.

"Pentcho Valev" wrote in message
...
On Apr 9, 10:33 pm, Tom Roberts wrote in
sci.physics.relativity:
bill wrote:
A person is located on a mountain top and is looking at a (very large)
clock (B) at sea-level.
He notices that clock B is ticking over at a slower rate than his own
clock (A) as theorized by Einstein in general theory and as ratified
by the Wallops Island experiment where a clock at sea-level, being
located in a strong gravitational tidal area, will tick over at a
slower rate than an identical clock on top of a mountain that is in a
weaker gravitational tidal area.

Note that what you call "gravitational tidal area" is really called
"Newtonian gravitational potential", valid in the Newtonian
approximation to GR. Indeed, tidal forces/effects are not involved
(tidal forces are second derivatives of the Newtonian potential).

Note that while A _SEES_ B tick at a slower rate, this does not imply
that clock B actually ticks at a slower rate than clock A. Indeed, in GR
this is modeled as an artifact of the COMPARISON [#], not as an effect
or modification of the clocks themselves: both clocks tick at their
usual (proper) rates, but their tick rates appear different when
situated and compared as you describe.

[#] This comparison is via EM signals in curved spacetime.

Is he entitled to be of the opinion that if he were to move to sea-
level his clock would be subjected to the same 'law' of physics thus
it will then be ticking over at a slower rate than it is before he
starts his descent?

No. See above -- this is not an effect ON THE CLOCKS, but rather OF THE
COMPARISON. Note that he is entitled to expect that if he carries his
clock down and puts it right next to B that the two clocks will tick at
the same rate.

Your statements are expressed with the implicit assumption there there
is some "global", "universal", or "absolute" way to determine a clock's
tick rate. In GR there is no such thing -- all you can do is compare
clocks to other clocks; the method of comparison can, and usually does,
affect the result.

Tom Roberts

: Honest Roberts, your cleverer brothers Einsteinians expose the
: "artifact of the COMPARISON" in a somewhat clearer way:

: http://www.people.fas.harvard.edu/~djmorin/book.html
: Chapter 14: "The equivalence principle has a striking consequence
: concerning the behavior of clocks in a gravitational field. It implies
: that higher clocks run faster than lower clocks. If you put a watch on
: top of a tower, and then stand on the ground, you will see the watch
: on the tower tick faster than an identical watch on your wrist. When
: you take the watch down and compare it to the one on your wrist, it
: will show more time elapsed."

: However, Honest Roberts, even your cleverer brothers Einsteinians
: would never answer the following question:

: Is the "artifact of the COMPARISON" (that is, gravitational time
: dilation) consistent with Einsteiniana's dicovery that the speed of
: light is CONSTANT in a gravitational field,

Both are nonsense. Einstein's discovery was just the contrary in both cases:

1. "Thus the clock goes more slowly if set up in the neighbourhood of
ponderable masses. From this it follows that the spectral lines of light
reaching us from the surface of large stars must appear displaced towards
the red end of the spectrum."
- http://www.alberteinstein.info/galle..._pp146-200.pdf
(p.198)

2. "according to the general theory of relativity, the law of the constancy
of the velocity of light in vacuo, which constitutes one of the two
fundamental assumptions in the special theory of relativity and to which we
have already frequently referred, cannot claim any unlimited validity"
- http://www.bartleby.com/173/22.html
- see also the same p.198 of the first ref. for details.

: or is it consistent with
: Einsteiniana's discovery that the speed of light is VARIABLE in a
: gravitational field and obeys e.g. Einstein's 1911 equation c'=c(1+gh/
: c^2) given by Newton's emission theory of light?

You should instead refer to his corrected equations of 1916 - which are NOT
given by Newton's theory.

Good luck.
Harald

On Apr 10, 12:48*pm, "harry"
wrote:
"Pentcho Valev" wrote:
: or is it consistent with
: Einsteiniana's discovery that the speed of light is VARIABLE in a
: gravitational field and obeys e.g. Einstein's 1911 equation c'=c(1+gh/
: c^2) given by Newton's emission theory of light?

You should instead refer to his corrected equations of 1916 - which are NOT
given by Newton's theory.

In 1915 Einstein replaced c'=c(1+gh/c^2) with c'=c(1+2gh/c^2):

http://www.mathpages.com/rr/s6-01/6-01.htm
"In geometrical units we define c_0 = 1, so Einstein's 1911 formula
can be written simply as c=1+phi. However, this formula for the speed
of light (not to mention this whole approach to gravity) turned out to
be incorrect, as Einstein realized during the years leading up to 1915
and the completion of the general theory. In fact, the general theory
of relativity doesn't give any equation for the speed of light at a
particular location, because the effect of gravity cannot be
represented by a simple scalar field of c values. Instead, the "speed
of light" at a each point depends on the direction of the light ray
through that point, as well as on the choice of coordinate systems, so
we can't generally talk about the value of c at a given point in a non-
vanishing gravitational field. However, if we consider just radial
light rays near a spherically symmetrical (and non- rotating) mass,
and if we agree to use a specific set of coordinates, namely those in
which the metric coefficients are independent of t, then we can read a
formula analogous to Einstein's 1911 formula directly from the
Schwarzschild metric. (...) In the Newtonian limit the classical
gravitational potential at a distance r from mass m is phi=-m/r, so if
we let c_r = dr/dt denote the radial speed of light in Schwarzschild
coordinates, we have c_r =1+2phi, which corresponds to Einstein's 1911
equation, except that we have a factor of 2 instead of 1 on the
potential term."

However the new equation, c'=c(1+2gh/c^2), was incompatible with the
gravitational redshift factor experimentally confirmed by Pound and
Rebka:

http://www.blazelabs.com/f-g-gcont.asp
"So, faced with this evidence most readers must be wondering why we
learn about the importance of the constancy of speed of light. Did
Einstein miss this? Sometimes I find out that what's written in our
textbooks is just a biased version taken from the original work, so
after searching within the original text of the theory of GR by
Einstein, I found this quote: "In the second place our result shows
that, according to the general theory of relativity, the law of the
constancy of the velocity of light in vacuo, which constitutes one of
the two fundamental assumptions in the special theory of relativity
and to which we have already frequently referred, cannot claim any
unlimited validity. A curvature of rays of light can only take place
when the velocity of propagation of light varies with position. Now we
might think that as a consequence of this, the special theory of
relativity and with it the whole theory of relativity would be laid in
the dust. But in reality this is not the case. We can only conclude
that the special theory of relativity cannot claim an unlimited domain
of validity ; its results hold only so long as we are able to
disregard the influences of gravitational fields on the phenomena
(e.g. of light)." - Albert Einstein (1879-1955) - The General Theory
of Relativity: Chapter 22 - A Few Inferences from the General
Principle of Relativity-. Today we find that since the Special Theory
of Relativity unfortunately became part of the so called mainstream
science, it is considered a sacrilege to even suggest that the speed
of light be anything other than a constant. This is somewhat
surprising since even Einstein himself suggested in a paper "On the
Influence of Gravitation on the Propagation of Light," Annalen der
Physik, 35, 1911, that the speed of light might vary with the
gravitational potential. Indeed, the variation of the speed of light
in a vacuum or space is explicitly shown in Einstein's calculation for
the angle at which light should bend upon the influence of gravity.
One can find his calculation in his paper. The result is c'=c(1+V/c^2)
where V is the gravitational potential relative to the point where the
measurement is taken. 1+V/c^2 is also known as the GRAVITATIONAL
REDSHIFT FACTOR."

Pentcho Valev

"Pentcho Valev" wrote in message
...
On Apr 10, 12:48 pm, "harry"
wrote:
"Pentcho Valev" wrote:
: or is it consistent with
: Einsteiniana's discovery that the speed of light is VARIABLE in a
: gravitational field and obeys e.g. Einstein's 1911 equation c'=c(1+gh/
: c^2) given by Newton's emission theory of light?

You should instead refer to his corrected equations of 1916 - which are
NOT
given by Newton's theory.

: In 1915 Einstein replaced c'=c(1+gh/c^2) with c'=c(1+2gh/c^2):

: http://www.mathpages.com/rr/s6-01/6-01.htm
[...]

In view of what you write below, you certainly did not understand the
explanation of mathpages that light speed is a function of direction and in
this case *perpendicular* to the star. But even that is irrelevant for your
problem.

: However the new equation, c'=c(1+2gh/c^2), was incompatible with the
: gravitational redshift factor experimentally confirmed by Pound and
: Rebka:

[..]

: "The result is c'=c(1+V/c^2)
: where V is the gravitational potential relative to the point where the
: measurement is taken. 1+V/c^2 is also known as the GRAVITATIONAL
: REDSHIFT FACTOR."

By chance I already cited the redshift prediction here above (in the part
you snipped). You failed to notice that gravitational redshift is only due
to the difference in resonance frequencies - neither of which depends on the
speed of light between the point of emission and the point of reception. And
I explained this too many times to you already.

Good luck - you need it.
Harald

"harry" wrote in message
...

"Pentcho Valev" wrote in message
...
On Apr 10, 12:48 pm, "harry"
wrote:
"Pentcho Valev" wrote:
: or is it consistent with
: Einsteiniana's discovery that the speed of light is VARIABLE in a
: gravitational field and obeys e.g. Einstein's 1911 equation c'=c(1+gh/
: c^2) given by Newton's emission theory of light?

You should instead refer to his corrected equations of 1916 - which are
NOT given by Newton's theory.

: In 1915 Einstein replaced c'=c(1+gh/c^2) with c'=c(1+2gh/c^2):

: http://www.mathpages.com/rr/s6-01/6-01.htm
[...]

In view of what you write below, you certainly did not understand the
explanation of mathpages that light speed is a function of direction and
in this case *perpendicular* to the star. But even that is irrelevant for
your problem.

: However the new equation, c'=c(1+2gh/c^2), was incompatible with the
: gravitational redshift factor experimentally confirmed by Pound and
: Rebka:

[..]

: "The result is c'=c(1+V/c^2)
: where V is the gravitational potential relative to the point where the
: measurement is taken. 1+V/c^2 is also known as the GRAVITATIONAL
: REDSHIFT FACTOR."

By chance I already cited the redshift prediction here above (in the part
you snipped). You failed to notice that gravitational redshift is only due
to the difference in resonance frequencies - neither of which depends on
the speed of light between the point of emission and the point of
reception. And I explained this too many times to you already.

Good luck - you need it.
Harald

However, there is more to it! Although Pentcho misdirected his attack, the
above equation of mathpages does appear to be erroneous. Reminder,
mathpages:

"we have c_r =1+2phi, which corresponds to Einstein's 1911
equation, except that we have a factor of 2 instead of 1 on the
potential term."

According to Einstein 1916, the tangential length of a measuring rod is
*not* affected by gravity. Thus the tangential speed of light should
decrease with increasing gravity just as he assumed in 1911, when he only
accounted for time dilation and forgot to account for a possible change of
length. By way of fast verification, when comparing the equations in his
1916 paper I do find the same factor 8*pi*r for tangential speed of light as
well as time dilation, which is consistent (locally the value c must be
found).
Apparently the different light bending prediction of 1916 was due to an
important detail of the calculation (which I never reproduced), and not due
to a change in the light speed equation as sometimes suggested in the
literature.

As a matter of fact, the information about this topic in the literature is
both scarce and confused. I would welcome constructive clarifications about
Einstein's 1916 paper (p.197-198) from people who studied Einstein's GRT. As
a reminder, you can get it he
http://www.alberteinstein.info/galle..._pp146-200.pdf

Harald

On Apr 10, 12:26*am, Pentcho Valev wrote:
On Apr 9, 10:33*pm, Tom Roberts wrote in
sci.physics.relativity:





bill wrote:
A person is located on a mountain top and is looking at a (very large)
clock (B) at sea-level.
He notices that clock B is ticking over at a slower rate than his own
clock (A) as theorized by Einstein in general theory and as ratified
by the Wallops Island experiment where a clock at sea-level, being
located in a strong gravitational tidal area, will tick over at a
slower rate than an identical clock on top of a mountain that is in a
weaker gravitational tidal area.

Note that what you call "gravitational tidal area" is really called
"Newtonian gravitational potential", valid in the Newtonian
approximation to GR. Indeed, tidal forces/effects are not involved
(tidal forces are second derivatives of the Newtonian potential).

Note that while A _SEES_ B tick at a slower rate, this does not imply
that clock B actually ticks at a slower rate than clock A. Indeed, in GR
this is modeled as an artifact of the COMPARISON [#], not as an effect
or modification of the clocks themselves: both clocks tick at their
usual (proper) rates, but their tick rates appear different when
situated and compared as you describe.

* * * * [#] This comparison is via EM signals in curved spacetime.

Is he entitled to be of the opinion that if he were to move to sea-
level his clock would be subjected to the same 'law' of physics thus
it will then be ticking over at a slower rate than it is before he
starts his descent?

No. See above -- this is not an effect ON THE CLOCKS, but rather OF THE
COMPARISON. Note that he is entitled to expect that if he carries his
clock down and puts it right next to B that the two clocks will tick at
the same rate.

Your statements are expressed with the implicit assumption there there
is some "global", "universal", or "absolute" way to determine a clock's
tick rate. In GR there is no such thing -- all you can do is compare
clocks to other clocks; the method of comparison can, and usually does,
affect the result.

Tom Roberts

Honest Roberts, your cleverer brothers Einsteinians expose the
"artifact of the COMPARISON" in a somewhat clearer way:

http://www.people.fas.harvard.edu/~djmorin/book.html
Chapter 14: "The equivalence principle has a striking consequence
concerning the behavior of clocks in a gravitational field. It implies
that higher clocks run faster than lower clocks. If you put a watch on
top of a tower, and then stand on the ground, you will see the watch
on the tower tick faster than an identical watch on your wrist. When
you take the watch down and compare it to the one on your wrist, it
will show more time elapsed."

However, Honest Roberts, even your cleverer brothers Einsteinians
would never answer the following question:

Is the "artifact of the COMPARISON" (that is, gravitational time
dilation) consistent with Einsteiniana's dicovery that the speed of
light is CONSTANT in a gravitational field, or is it consistent with
Einsteiniana's discovery that the speed of light is VARIABLE in a
gravitational field and obeys e.g. Einstein's 1911 equation c'=c(1+gh/
c^2) given by Newton's emission theory of light?

Pentcho Valev

Einstein arrived to Special Relativity.

The next is General Relativity.

Nobody else can put together the Complete Relativity, nor many want.
Many
theoretical physicists were looking for the Unified Theory.

Three steps.

The created Special Inertia for dark matter. It worked.

*c'=c(1+gh/c^2) given by Newton's emission theory of light?

The old fart Pentcho is back jacking off to his old idiocy.

He is darkened by his French side. You by your American side. "He is
back Jack. Hey, Jackass!"

"harry" wrote:
...the above equation of mathpages does appear to be erroneous. Reminder,
mathpages: "we have c_r =1+2phi, which corresponds to Einstein's 1911
equation, except that we have a factor of 2 instead of 1 on the
potential term."

That equation is correct, assuming "c_r" represents the radial speed
in Schwarzschild coordinates. What makes you think it isn't correct?

Apparently the different light bending prediction of 1916 was due to an
important detail of the calculation (which I never reproduced)...

The calculation can be found in many good references (including the
mathpages you mentioned above), and the source of the doubling of the
deflection is clearly shown.

... and not due to a change in the light speed equation as sometimes
suggested in the literature.

The same fact that causes the speed of light to be different in
different directions also results in the factor of 2 in the
deflection. Perhaps this is what the literature is suggesting?

As a matter of fact, the information about this topic in the literature is
both scarce and confused.

I know a guy who was married fived times, and says each of his wives
was impossible to live with.

"Henry Sharma" wrote in message
...
"harry" wrote:
...the above equation of mathpages does appear to be erroneous. Reminder,
mathpages: "we have c_r =1+2phi, which corresponds to Einstein's 1911
equation, except that we have a factor of 2 instead of 1 on the
potential term."

That equation is correct, assuming "c_r" represents the radial speed
in Schwarzschild coordinates. What makes you think it isn't correct?

Ai! I forgot that Pencho just cited the radial speed eventhough I noticed it
in my earlier posting! Indeed, that's correct, thanks for reminding me. :-)

Apparently the different light bending prediction of 1916 was due to an
important detail of the calculation (which I never reproduced)...

The calculation can be found in many good references (including the
mathpages you mentioned above), and the source of the doubling of the
deflection is clearly shown.

In the meantime I found a more detailed calculation in the GRT textbook by
Adler, Bazin and Schiffer. They repeat Einstein's calculation of double
bending using the Huygens principle with more detail than Einstein in 1916.

... and not due to a change in the light speed equation as sometimes
suggested in the literature.

The same fact that causes the speed of light to be different in
different directions also results in the factor of 2 in the
deflection. Perhaps this is what the literature is suggesting?

Perhaps.

As a matter of fact, the information about this topic in the literature is
both scarce and confused.

I know a guy who was married fived times, and says each of his wives
was impossible to live with.

:-))

Thanks,
Harald