How does the Light Move?

On Dec 26, 7:08*am, Antares 531 wrote:
On Fri, 25 Dec 2009 17:47:50 -0800 (PST), Newberry





wrote:
On Dec 25, 3:20*pm, Antares 531 wrote:
On Wed, 23 Dec 2009 19:12:00 -0800 (PST), Newberry

wrote:
On Dec 23, 7:06*am, PD wrote:
On Dec 22, 11:45*pm, Newberry wrote:

On Dec 22, 5:27*am, (Daryl McCullough)
wrote:

Arindam Banerjee says...

The speed of light in a dielectric medium is c/(square root of the
refractive index). I worked in the microwave area for over 8 years,
desigining strip line circuits, and it was an experimental fact that light
would travel slowly - the line lengths were thus adjusted to give the
required phase differences.

Yes, that is true. The current understanding of dielectrics at the microscopic
level is this: An external electromagnetic field is applied to a material. In
response to this external field, charges and dipoles in the material move and
change orientation. This in turn produces its own response field, which adds to
the original external field. In the case of magnetic fields, the net result is
to increase the field, as magnetic dipoles tend to line up with external
magnetic fields. In the case of electric fields, the net result is to decrease
the field, because charges and electric dipoles move around to cancel the
external field.

The propagation of electromagnetic fields in matter thus includes both the
vacuum propagation of the fields and also the (approximately linear) response of
the matter. These combined effects propagate slower than pure electromagnetic
fields in vacuum.

It was the Michelson Morley Interferomtry experiment that gave the wrong
impression (based upon a huge bungle) about all the e=mcc stuff. *It is most
unworthy for any man of honour to believe that crap, especially when I have
found out the correct equation linking mass and energy from first
principles.

I don't think so.

--
Daryl McCullough
Ithaca, NY

Can you explain the paradox of twins?

What paradox? There is a teaching puzzle, designed specifically to
highlight where students have oversimplified what relativity says. Is
this what you mean?- Hide quoted text -

Let there be a clock A on Earth and a clock B on a rocket. Accelerate
the rocket to 0.5c. Let it fly much longer than the time of
acceleration. The clock B is ticking more slowly with respect to A,
and A is ticking more slowly with respect B. Now reverse the direction
of the rocket and fly it back to Earth. The time of deceleration/
acceleration is insignificant compared to the time of flight. The
clock B is still ticking more slowly with respect to A, and A is
ticking more slowly with respect to B. Now decelerate the rocket and
land it on Earth. Time of deceleration insignificant. Compare the two
clocks. Clock B is behind clock A, and clock A is behind clock B.

Take this a bit farther...two photons leave the surface of the sun at
the same time and travel along parallel lines. What is the speed of
photon A relative to photon B? Assume, for the sake of this thought
experiment that it is possible to measure these velocities from each
photon. Think of this as hopping onto photon B for a ride and
measuring the speed of photon A while you are on this journey.

I suppose the answer is that in fact you cannot measure the velocity
of one photon from another.

Why? Okay, I realize this was just a thought experiment and could
never be objectively tested, but it seems rational, to me.

Taking this a bit farther, if space ships could travel at c, and two
such space ships were traveling along parallel lines, near each other,
what would each space ship observe as the velocity of the other?

0. (The speed would be c - epsilon.) The photons have the obligation
(according to SR) to travel at c in any inertial frame. Space ships do
not. In SR everything is based on verification. Since a photon cannot
be absorbed in another photon there is no way to say what velocity
they have wrt one another. I suppose you could dispute this account
but there is no major inconsistency.

You could probably also say that the photons travel at c in all
inertial frames except the frames that themelves travel at c. Then two
parallel photons would have the velocity 0 and two photons traveling
in the opposite directions would have the velocity 2c.

On Dec 23, 9:12*pm, Newberry wrote:
On Dec 23, 7:06*am, PD wrote:



On Dec 22, 11:45*pm, Newberry wrote:

On Dec 22, 5:27*am, (Daryl McCullough)
wrote:

Arindam Banerjee says...

The speed of light in a dielectric medium is c/(square root of the
refractive index). I worked in the microwave area for over 8 years,
desigining strip line circuits, and it was an experimental fact that light
would travel slowly - the line lengths were thus adjusted to give the
required phase differences.

Yes, that is true. The current understanding of dielectrics at the microscopic
level is this: An external electromagnetic field is applied to a material. In
response to this external field, charges and dipoles in the material move and
change orientation. This in turn produces its own response field, which adds to
the original external field. In the case of magnetic fields, the net result is
to increase the field, as magnetic dipoles tend to line up with external
magnetic fields. In the case of electric fields, the net result is to decrease
the field, because charges and electric dipoles move around to cancel the
external field.

The propagation of electromagnetic fields in matter thus includes both the
vacuum propagation of the fields and also the (approximately linear) response of
the matter. These combined effects propagate slower than pure electromagnetic
fields in vacuum.

It was the Michelson Morley Interferomtry experiment that gave the wrong
impression (based upon a huge bungle) about all the e=mcc stuff. *It is most
unworthy for any man of honour to believe that crap, especially when I have
found out the correct equation linking mass and energy from first
principles.

I don't think so.

--
Daryl McCullough
Ithaca, NY

Can you explain the paradox of twins?

What paradox? There is a teaching puzzle, designed specifically to
highlight where students have oversimplified what relativity says. Is
this what you mean?- Hide quoted text -

Let there be a clock A on Earth and a clock B on a rocket. Accelerate
the rocket to 0.5c. Let it fly much longer than the time of
acceleration. The clock B is ticking more slowly with respect to A,
and A is ticking more slowly with respect B. Now reverse the direction
of the rocket and fly it back to Earth. The time of deceleration/
acceleration is insignificant compared to the time of flight.

This is where the oversimplification occurs. A remarkable thing
happens to the reading on clock A, as seen on the rocket B, during the
acceleration back toward home.

The
clock B is still ticking more slowly with respect to A, and A is
ticking more slowly with respect to B. Now decelerate the rocket and
land it on Earth. Time of deceleration insignificant. Compare the two
clocks. Clock B is behind clock A, and clock A is behind clock B.

On Dec 25, 12:05*am, Newberry wrote:
On Dec 23, 10:10*pm, Sam Wormley wrote: On 12/24/09 12:01 AM, Newberry wrote:

If you are in a free fall does your clock still go more slowly? Since
there is no pull there should be no red shift.

* *GPS Satellites are in free fall.

This is a good example actually. The satellite clock will be delayed
by about 7 ìs/day because it moves at v = 4 km/s. [Is this the orbital
speed or speed wrt the GPS receiver?] Does the satellite also see my
clock slipping 7 ìs/day?

The GPS satellite is not in an inertial frame of reference. It is
*constantly* accelerating. Which the Earth clock is not.

This is precisely the lesson that the twin puzzle is aimed to
instruct.




See: Relativistic Effects on Satellite Clocks
*http://relativity.livingreviews.org/...=node5....Hide quoted text -

- Show quoted text -

On Dec 26, 9:57*am, PD wrote:
On Dec 23, 9:12*pm, Newberry wrote:





On Dec 23, 7:06*am, PD wrote:

On Dec 22, 11:45*pm, Newberry wrote:

On Dec 22, 5:27*am, (Daryl McCullough)
wrote:

Arindam Banerjee says...

The speed of light in a dielectric medium is c/(square root of the
refractive index). I worked in the microwave area for over 8 years,
desigining strip line circuits, and it was an experimental fact that light
would travel slowly - the line lengths were thus adjusted to give the
required phase differences.

Yes, that is true. The current understanding of dielectrics at the microscopic
level is this: An external electromagnetic field is applied to a material. In
response to this external field, charges and dipoles in the material move and
change orientation. This in turn produces its own response field, which adds to
the original external field. In the case of magnetic fields, the net result is
to increase the field, as magnetic dipoles tend to line up with external
magnetic fields. In the case of electric fields, the net result is to decrease
the field, because charges and electric dipoles move around to cancel the
external field.

The propagation of electromagnetic fields in matter thus includes both the
vacuum propagation of the fields and also the (approximately linear) response of
the matter. These combined effects propagate slower than pure electromagnetic
fields in vacuum.

It was the Michelson Morley Interferomtry experiment that gave the wrong
impression (based upon a huge bungle) about all the e=mcc stuff. *It is most
unworthy for any man of honour to believe that crap, especially when I have
found out the correct equation linking mass and energy from first
principles.

I don't think so.

--
Daryl McCullough
Ithaca, NY

Can you explain the paradox of twins?

What paradox? There is a teaching puzzle, designed specifically to
highlight where students have oversimplified what relativity says. Is
this what you mean?- Hide quoted text -

Let there be a clock A on Earth and a clock B on a rocket. Accelerate
the rocket to 0.5c. Let it fly much longer than the time of
acceleration. The clock B is ticking more slowly with respect to A,
and A is ticking more slowly with respect B. Now reverse the direction
of the rocket and fly it back to Earth. The time of deceleration/
acceleration is insignificant compared to the time of flight.

This is where the oversimplification occurs. A remarkable thing
happens to the reading on clock A, as seen on the rocket B, during the
acceleration back toward home.

I would still like to know why the Earth does not observe B's red
shift during B's acceleration back towards home.

The
clock B is still ticking more slowly with respect to A, and A is
ticking more slowly with respect to B. Now decelerate the rocket and
land it on Earth. Time of deceleration insignificant. Compare the two
clocks. Clock B is behind clock A, and clock A is behind clock B.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

On Dec 18, 11:49*pm, Pentcho Valev wrote:
On Dec 18, 3:27 am, Tom Roberts wrote in
sci.physics.relativity:

In our best model of light, QED, the photon is NOT a particle. Neither is it a
wave.

* * * * There are more things in heaven and earth, Horatio,
* * * * Than are dreamt of in your philosophy. -- Shakespeare

There is no expectation that words and concepts from your everyday life capture
the essence of phenomena far removed from you everyday experience. Photons and
quantum phenomena are indeed far removed (you experience light, not photons or
their quantum implications).

Honest Roberts stop introducing red herrings! You know that the
problem crucial for contemporary physics is: Does the speed of light
depend on the speed of the light source, as Newton's emission theory
of light assumes, or is it independent of the speed of the light
source, as Einstein's special relativity assumes. I suggest that you
return to and develop the following insights of yours:

http://groups.google.com/group/sci.p...sg/44abc7dbb30...

John Norton: "THE MICHELSON-MORLEY EXPERIMENT IS FULLY COMPATIBLE WITH
AN EMISSION THEORY OF LIGHT THAT CONTRADICTS THE LIGHT POSTULATE."

Tom Roberts: "Sure. The fact that this one experiment is compatible
with other theories does not refute relativity in any way. The full
experimental record refutes most if not all emission theories, but not
relativity."

Pentcho Valev: "THE POUND-REBKA EXPERIMENT IS FULLY COMPATIBLE WITH AN
EMISSION THEORY OF LIGHT THAT CONTRADICTS THE LIGHT POSTULATE."

Tom Roberts: "Sure. But this experiment, too, does not refute
relativity. The full experimental record refutes most if not all
emission theories, but not relativity."

Pentcho Valev


According to an outside observer, our entire galaxy is traveling away
at the speed of light.

~ BG

PD says...

The GPS satellite is not in an inertial frame of reference. It is
*constantly* accelerating. Which the Earth clock is not.

I'm sure you don't need to be told this, but for others reading,
the Earth clock is not in an inertial frame of reference, either.
For one thing, the Earth is rotating. For another, the Earth has
gravity, so something on the surface of the Earth is accelerating
upward relative to an object in free-fall.

--
Daryl McCullough
Ithaca, NY

yeah, one has to account for acceleration in both grond & orbital
frames.
surfer's paper is good, because it accounts for the so-called null
results of M&M, DCMiller et al -- also, in a graph (fig.3 .-);
it's not perfect, but it's still great!

http://arxiv.org/abs/0804.0039
"......The spacecraft observations demonstrate again that the speed
of
light is not invariant, and is isotropic only with respect to a
dynamical 3-space....."

I'm sure you don't need to be told this, but for others reading,
the Earth clock is not in an inertial frame of reference, either.
For one thing, the Earth is rotating. For another, the Earth has
gravity, so something on the surface of the Earth is accelerating
upward relative to an object in free-fall.

--l'OEuvre,
http://wlym.com
http://www.21stcenturysciencetech.co...istic_Moon.pdf

FCUK Copenhagen free carbon-credit trade rip-off;
put a tariff on imported energy!

On Dec 26, 9:59*am, PD wrote:
On Dec 25, 12:05*am, Newberry wrote:

On Dec 23, 10:10*pm, Sam Wormley wrote: On 12/24/09 12:01 AM, Newberry wrote:

If you are in a free fall does your clock still go more slowly? Since
there is no pull there should be no red shift.

* *GPS Satellites are in free fall.

This is a good example actually. The satellite clock will be delayed
by about 7 ìs/day because it moves at v = 4 km/s. [Is this the orbital
speed or speed wrt the GPS receiver?] Does the satellite also see my
clock slipping 7 ìs/day?

The GPS satellite is not in an inertial frame of reference. It is
*constantly* accelerating. Which the Earth clock is not.

This is precisely the lesson that the twin puzzle is aimed to
instruct.

So the satellite is constantly being accelerated towards the Earth and
this causes a pseudo-gravitational field pointing outwards? And this
causes the observer on the Earth to see the satellite's red shift?
[canceled by the GR blue shift.]

See: Relativistic Effects on Satellite Clocks
*http://relativity.livingreviews.org/...ode5....quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

On Dec 27, 8:16*am, (Daryl McCullough)
wrote:
PD says...

The GPS satellite is not in an inertial frame of reference. It is
*constantly* accelerating. Which the Earth clock is not.

I'm sure you don't need to be told this, but for others reading,
the Earth clock is not in an inertial frame of reference, either.
For one thing, the Earth is rotating. For another, the Earth has
gravity, so something on the surface of the Earth is accelerating
upward relative to an object in free-fall.

this is true...


--
Daryl McCullough
Ithaca, NY

On Dec 26, 4:29*pm, Newberry wrote:
On Dec 26, 9:57*am, PD wrote:

On Dec 23, 9:12*pm, Newberry wrote:

On Dec 23, 7:06*am, PD wrote:

On Dec 22, 11:45*pm, Newberry wrote:

On Dec 22, 5:27*am, (Daryl McCullough)
wrote:

Arindam Banerjee says...

The speed of light in a dielectric medium is c/(square root of the
refractive index). I worked in the microwave area for over 8 years,
desigining strip line circuits, and it was an experimental fact that light
would travel slowly - the line lengths were thus adjusted to give the
required phase differences.

Yes, that is true. The current understanding of dielectrics at the microscopic
level is this: An external electromagnetic field is applied to a material. In
response to this external field, charges and dipoles in the material move and
change orientation. This in turn produces its own response field, which adds to
the original external field. In the case of magnetic fields, the net result is
to increase the field, as magnetic dipoles tend to line up with external
magnetic fields. In the case of electric fields, the net result is to decrease
the field, because charges and electric dipoles move around to cancel the
external field.

The propagation of electromagnetic fields in matter thus includes both the
vacuum propagation of the fields and also the (approximately linear) response of
the matter. These combined effects propagate slower than pure electromagnetic
fields in vacuum.

It was the Michelson Morley Interferomtry experiment that gave the wrong
impression (based upon a huge bungle) about all the e=mcc stuff. *It is most
unworthy for any man of honour to believe that crap, especially when I have
found out the correct equation linking mass and energy from first
principles.

I don't think so.

--
Daryl McCullough
Ithaca, NY

Can you explain the paradox of twins?

What paradox? There is a teaching puzzle, designed specifically to
highlight where students have oversimplified what relativity says. Is
this what you mean?- Hide quoted text -

Let there be a clock A on Earth and a clock B on a rocket. Accelerate
the rocket to 0.5c. Let it fly much longer than the time of
acceleration. The clock B is ticking more slowly with respect to A,
and A is ticking more slowly with respect B. Now reverse the direction
of the rocket and fly it back to Earth. The time of deceleration/
acceleration is insignificant compared to the time of flight.

This is where the oversimplification occurs. A remarkable thing
happens to the reading on clock A, as seen on the rocket B, during the
acceleration back toward home.

I would still like to know why the Earth does not observe B's red
shift during B's acceleration back towards home.

Here's a nice short presentation about it.
http://math.ucr.edu/home/baez/physic...n_paradox.html




The
clock B is still ticking more slowly with respect to A, and A is
ticking more slowly with respect to B. Now decelerate the rocket and
land it on Earth. Time of deceleration insignificant. Compare the two
clocks. Clock B is behind clock A, and clock A is behind clock B.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -