Some troubling assumptions of SR

On Sat, 24 Feb 2007 21:15:50 GMT, Michael Press
wrote:

In article
,
Lester Zick wrote:

On Fri, 23 Feb 2007 23:19:18 -0800, Michael Press
wrote:

In article ,
Bob Kolker wrote:

Michael Press wrote:

So now geometric contraction is speculation? What is
geometric contraction?

Distance contraction and time dilation have been verified experimentally
with pi muons.

Yes, I know. David Frisch taught the freshman physics
problem solving session I was in. I was asking to see
if LZ would tell me exactly what he makes of it.

Obviously it failed.

LZ writes at length and will not clarify exactly what
he means by anything he says.

Well I thought that was pretty clarified.

~v~~

On Feb 24, 4:12 am, "George Dishman" wrote:
wrote in message

oups.com...





On Feb 23, 8:56 am, "George Dishman" wrote:
wrote in message
groups.com...
...
If you want to get precise you could use a sound beam. You can ame a
beam of sound at someone 100 meters away and the person standing next
to them wont hear a thing.

http://www.meyersound.com/support/pa...g/figure_3.jpg

Interesting, however sound is a longitudinal wave so
I'm always sceptical of those analogies. If I wanted
accuracy I would use Maxwell's Equations which were
intended for EM and should be equally applicable to
an aether theory.

Considering that Maxwell's equations were derived from aether theory I
am sure they would work perfectly, so long as they are properly
applied. But we weren't talking about calculating a result. We were
talking about doing an actual experiment to see if predictions matched
up with with observed results.

I don't agree, I think the experiment has already been
done first by Bradley in the 1850s IIRC and recently by
Hipparcos. The observed amount of aberration is well
documented. What is in question is whether a dragged
aether predicts the obsereved aberration or not and my
take is that Maxwell's Equations would be the definitive
way to check that.

Yes, I am aware of Bradley's work which established that stellar
aberration exists. The experiment I was suggesting shows that a
dragged media could could account for the effect. You seemed
receptive to the idea, even suggesting what equipment should be used.
But now you want to revert to calculating a result. I'm not sure how
you intend to apply Maxwell's equations but would note that they are
in agreement with SR, and they were derived from a vortex aether
theory so they must be in agreement with that as well. If your
analysis some how comes up with the ather theory predicting a result
that differs from SR I would suggest looking at how things are defined
in the two theories. As I have previously shown the dragged aether
definiton of abberation provided by Mitchell Jones causes the two
theories to not agree.

With aether theory you don't know the
rest frame of the aether. It could be fully dragged, partially
dragged, or not dragged at all as in LET. At least with air we know
what its state of motion is, and we can work with speeds that are a
fair fraction of the speed of sound.

My reason for suggesting the "sound beam" was because it could be
accurately aimed and the sound path could be plotted. Step a few feet
off to either side of the path and you would hear nothing.

OK, if you wanted to do that I would suggest you use two
crystals and launch a transverse (shear) wave into one.

Tx
========
|
v
|
========

Then add a second crystal below with a detector Rx fixed
to the opposite face

Tx
========
|
v first crystal at rest
|
========
|
v --- second crystal in motion
|
========
Rx

The second crystal must be in motion relative to the first.
Now the trick is predict what happens at the boundary
between the crystals bearing in mind it is a transverse
wave. I think that's difficult and probably not intuitive.

Last time I checked I wasn't living inside a crystal Sound in air
may not be a perfect analogy but I think it is closer to the aether
than a solid crystal.

I get the impression that Mitchell Jones is a supporter of an aether
theory. His definition of aberation uses a path defined by the rest
frame of the medium. There is no way that he can get results based on
that definition to agree with SR.

He doesn't need to, he needs to get it to agree with
observed aberration. Of course the same theory might
then fail other tests but that's not the topic ;-)

When different definitions are used the two theories can predict the
same result but not be in agreement on why those results are
observed. For SR there can be no aberation for two objects at rest in
the same frame. Period. End of story.

True and we are discussing whether dragged aether can explain
observed aberration so it is a given that the source and
observer must be in relative motion.

Tell that to Mitchell not me.

With the definition Mitchell
provided for aberation, and the method used for determining the path,
he ends up saying there is aberation but it is canceled out by drift.
There is no disagreement about what is observed but there is
disagreement about whether there is aberation or not because of the
different definitions.

I agree, aberration is observed but can a dragged aether
explain it? All the sources I have seen say no and my own
thoughts based on Huygens method tend to agree.

Read the above again. I said that using Mitchell's definition of
abberation his dragged aether theory predicts abberation even though
there is no relative motion between the source and receiver. Change
the definition of abberation to the same one used by SR and the
theories are in agreement.

Bruce

In article .com,
"PD" wrote:

snip

The perspective issue is a little closer to the truth. Again the
confusion is about what is real. "Length" as a strictly spatial
quantity by definition is also intrinsically a *projection* of a real,
4D property. While the 4D property (not strictly speaking a length) is
observer-independent, it shouldn't be surprising that the projection
of a 4D property onto 3D space is observer-dependent.

The situation is comparable to one in which only angular measures are
available for three-dimensional observations. From a distance, each of a
perfect cube's edges subtends a different arc in the visual field,
depending on the observer's position. But by applying appropriate
transformations to the angular coördinates obtained from different
points of view, in effect undoing the projection of the 3-D scene onto a
2-D retina (or other sensor), the invariant properties of the cube can
be calculated. There's no illusion involved unless the observed angular
measurements are mistaken for absolute distances; they're equally real
but with different realms of applicability.

You may have seen the Penrose/Escher 'impossible cube', which has edges
connecting to the opposite corners:

http://www.vitruvius.com.br/arquitextos/arq000/imagens/236_3.jpg.

People have made photographs of what appears to be such an object by
shooting a specially constructed model from an angle that makes certain
disconnected members overlap. Such a photo is a faithful representation
of the real object, so can scarcely be called an illusion. That only
arises when we insist on perceiving the overlaps as joints; the
impossible figure is a construct of our minds, fooled by cues that are
usually quite reliable for navigating our surroundings but can be
contrived to mislead.

--
Odysseus

wrote in message
oups.com...
On Feb 24, 4:12 am, "George Dishman" wrote:
wrote in message
oups.com...
On Feb 23, 8:56 am, "George Dishman" wrote:
wrote in message
groups.com...
...
If you want to get precise you could use a sound beam. You can ame
a
beam of sound at someone 100 meters away and the person standing
next
to them wont hear a thing.

http://www.meyersound.com/support/pa...g/figure_3.jpg

Interesting, however sound is a longitudinal wave so
I'm always sceptical of those analogies. If I wanted
accuracy I would use Maxwell's Equations which were
intended for EM and should be equally applicable to
an aether theory.

Considering that Maxwell's equations were derived from aether theory I
am sure they would work perfectly, so long as they are properly
applied. But we weren't talking about calculating a result. We were
talking about doing an actual experiment to see if predictions matched
up with with observed results.

I don't agree, I think the experiment has already been
done first by Bradley in the 1850s IIRC and recently by
Hipparcos. The observed amount of aberration is well
documented. What is in question is whether a dragged
aether predicts the obsereved aberration or not and my
take is that Maxwell's Equations would be the definitive
way to check that.

Yes, I am aware of Bradley's work which established that stellar
aberration exists. The experiment I was suggesting shows that a
dragged media could could account for the effect. You seemed
receptive to the idea, even suggesting what equipment should be used.
But now you want to revert to calculating a result.

What I was saying was that I felt a slightly different
experiment would be needed to simulate it, EM waves are
transverse and we need a sliding boundary so the
alternative I suggested seemed closer and perhaps
feasible although still not perfect. However, I still
maintain that to test a theory, you make a prediction
using that theory and compare against actual observation.
The observations already exist so I really see no need to
try to duplicate them with a poorer equivalent when we
know the result from the real thing.

I'm not sure how
you intend to apply Maxwell's equations

I guess take a distant point source and see how the waves
propagate through the boundary. The hard part would be
detailing how the aether was represented

but would note that they are
in agreement with SR, and they were derived from a vortex aether
theory so they must be in agreement with that as well.

Well as I understand it, only an un-dragged Lorentzian
aether is fully compatible with SR so some differences
should show up using a dragged Galilean aether. The
question would be whether there is a difference in this
particular observation. For example there is no difference
in the MMx so perhaps that could apply here too.

If your
analysis some how comes up with the ather theory predicting a result
that differs from SR I would suggest looking at how things are defined
in the two theories. As I have previously shown the dragged aether
definiton of abberation provided by Mitchell Jones causes the two
theories to not agree.

I agree you have to be careful to use the same quantity
in each but that's another question. What I suggested at
the start was that I believe it is understood generally
that a dragged aether would not be compatible with the
observation of stellar aberration and that's as far as I
would go.

With aether theory you don't know the
rest frame of the aether. It could be fully dragged, partially
dragged, or not dragged at all as in LET. At least with air we know
what its state of motion is, and we can work with speeds that are a
fair fraction of the speed of sound.

My reason for suggesting the "sound beam" was because it could be
accurately aimed and the sound path could be plotted. Step a few feet
off to either side of the path and you would hear nothing.

OK, if you wanted to do that I would suggest you use two
crystals and launch a transverse (shear) wave into one.

Tx
========
|
v
|
========

Then add a second crystal below with a detector Rx fixed
to the opposite face

Tx
========
|
v first crystal at rest
|
========
|
v --- second crystal in motion
|
========
Rx

The second crystal must be in motion relative to the first.
Now the trick is predict what happens at the boundary
between the crystals bearing in mind it is a transverse
wave. I think that's difficult and probably not intuitive.

Last time I checked I wasn't living inside a crystal

According to aether theory you were To support transverse
waves, you need such a material and with very specific
properties.

Sound in air
may not be a perfect analogy but I think it is closer to the aether
than a solid crystal.

Air cannot support transverse waves at all.

I get the impression that Mitchell Jones is a supporter of an aether
theory. His definition of aberation uses a path defined by the rest
frame of the medium. There is no way that he can get results based
on
that definition to agree with SR.

He doesn't need to, he needs to get it to agree with
observed aberration. Of course the same theory might
then fail other tests but that's not the topic ;-)

When different definitions are used the two theories can predict the
same result but not be in agreement on why those results are
observed. For SR there can be no aberation for two objects at rest in
the same frame. Period. End of story.

True and we are discussing whether dragged aether can explain
observed aberration so it is a given that the source and
observer must be in relative motion.

Tell that to Mitchell not me.

I was just agreeing with you. Observed aberration is due to
the varying velocity of the Earth in orbit as you know and
that is what his dragged aether must explain.

With the definition Mitchell
provided for aberation, and the method used for determining the path,
he ends up saying there is aberation but it is canceled out by drift.
There is no disagreement about what is observed but there is
disagreement about whether there is aberation or not because of the
different definitions.

I agree, aberration is observed but can a dragged aether
explain it? All the sources I have seen say no and my own
thoughts based on Huygens method tend to agree.

Read the above again. I said that using Mitchell's definition of
abberation his dragged aether theory predicts abberation even though
there is no relative motion between the source and receiver.

That would be another problem but harder to test.

Change
the definition of abberation to the same one used by SR and the
theories are in agreement.

My understanding is that dragged aether predicts no
aberration when in fact we observe it, that was the
original point. SR certainly gets it right so I think
their predictions differ.

George

Problem is all those frames of reference with different FLTs overlap
in space and objects can't just pick and choose which FLT they want to
use and which not since they all are supposed to apply equally.

What do you mean when you say that the frames 'overlap'? The only
meaning I can get is essentially the same assaying that polar and
rectangular coordinates overlap. Yes, they are different ways of
describing the same phenomena.

Also, it is often much simpler algebraically to do calculations in one
frame rather than another.

I'll be sure to mention that to the next muon I see.

Non-responsive, silly comment noted.


these different coordinate systems is as useful as, say, shifting
back and forth between polar and rectangular coordiantes.

Difference is that polar and rectangular coordinates are not
temporally dependent anisometries. They're just different versions of
the same thing.

Actually, the analogy is fairly precise. Different frames are just
'different versions of the same thing' to use your terminolology.
Yes, they transform both the space and the time coordinates, but
so what? The rectangular to polar conversion is much more anisotropic.

--Dan Grubb

In article ,
"George Dishman" wrote:

"Mitchell Jones" wrote in message
...
In article ,
"George Dishman" wrote:
"Mitchell Jones" wrote in message
...
In article ,
"George Dishman" wrote:
...
For a gravitationally entrained aether, there should be
no aberration because the light is dragged along with
the aether which in turn is dragged by the Earth.

***{Incorrect. We are not talking about all the aether in the universe
being dragged along by the Earth. We are talking about only that
portion
which is in the region of the Earth's gravitational dominance being
dragged along by the Earth.

Right, and since the ligh't transverse motion realtive
to the earth is eliminated, so is aberration.

***{No. Aberration is a deviation in the pathway of a signal as it
passes into a "receiver," and is due to the component of motion of the
receiver perpendicular to the previously established path of the signal.

Right. Now as I understand the argument, the aether is moving
with the telescope so there is no transverse motion relative
to the receiver.

***{In the context of the gravitationally entrained aether theory, there
is no transverse motion relative to a ground-based telescope. However,
the telescope is not the "receiver," where the calculation of aberration
is concerned. The "receiver," instead, is the pool of aether entrained
by the Earth. The question at issue is whether the direction of the
incoming photons will be deviated in accordance with Tan^-1 (V1/V2)
when the wave that they comprise transitions from the Sun's pool to the
Earth's pool. --MJ}***

The magnitude of the deviation is Tan^-1 (V1/V2) where V1 is the
component of velocity of the receiver perpendicular to the previously
established signal pathway, and V2 is the velocity of the signal
relative to the external medium--i.e., the medium outside of the
receiver.

The "receiver," in the case we are discussing, is the pool of aether
entrained by the Earth,

I see the "receiver" as being the telescope itself.

***{There is obviously no aberration as the beam of light enters the
barrel of a ground-based telescope: there is no relative motion between
the telescope and the pool of aether entrained by the Earth. Result: V1
= 0 miles/sec, and the aberration angle is Tan^-1 (V1/V2) = Tan^-1
(0/186000) = 0 degrees. Thus the telescope must be pointed straight down
the incoming beam of light from the star, as it exists in the Earth's
pool. The question, however, is whether the beam of light in the Earth's
pool is a straight line extension of the beam in the Sun's pool. And,
since the Earth's pool has a component of motion of up to 18 miles/sec
perpendicular to an incoming beam of light from the Sun's pool, it
follows that as the beam transitions between the two pools, there will
in fact be an aberration in the amount of up to Tan^-1 (18/186000) =
..00554 degrees, or 19.96 arcseconds. --MJ}***

and the incoming lightpath (from a distant star)
lies in the pool of aether entrained by the Sun. Since the Earth's pool
moves within the Sun's pool at 18 miles/'sec, due to the motion of the
Earth in its orbit, it follows that the Earth's pool may have a
component of motion perpendicular to the incoming lightpath of as much
as 18 miles/sec. Result: the new lightpath that will be established in
the Earth's pool can deviate from that of the prior pathway by as much
as Tan^-1 (18/186000) = 5.5x10^-3 degrees, or 19.96 arcseconds.

What this means is that the pathway of the signal will be aberrated when
it enters the Earth's pool. Ground based telescopes will, as a
consequence have to be aimed along the new pathway, in order to be
centered on the star.

Bottom line: the aberration does not take place as the light enters the
telescope, but rather takes place as it transits from the Sun's pool to
the Earth's pool.

Take a simple version, imagine there is a sharp boundary
between the two regions:


Star

----
----
---- wavefronts
----
=====++++===== boundary

-- Earth dragged aether

Using Huygens construction (we are talking classical waves
after all), the wavefronts which were perpendicular to the
direction of motion hit the boundary simultaneously. The
next construction results in a wavefront still perpendicular
to the boundary which then propagates to the telescope.

Sun dragged aether --

=====++++===== boundary
----
---- wavefronts
----
||
|| telescope
||

Clearly the telescope is perpendicular to the boundary which
would also be the case if the Earth were not moving - no
aberration.

***{The argument you are using rests on the premise (a) that light waves
are continuous (do not consist of discrete parts), and (b) that the
plane of the waves must be tilted in order for aberration to occur. If
such premises were a necessary part of a wave theory, then all wave
theories would be refuted, since they would obviously result in no
aberration, whether the aether existed or not. Since aberration has been
observed and measured for some 300 years, it is clear that the sort of
wave interpretation you are using is incorrect.

In a defensible wave theory, light waves are not mathematically
continuous in nature. Instead, they result from the mass behavior of the
particles, called photons, that comprise them. When the photons in an
incoming plane wavefront cross from the pool of aether entrained by the
Sun to that entrained by the Earth, each photon is individually deviated
from its former path in the amount of Tan^-1 (V1/V2). The wave front
itself need not be tilted. The direction of the photons within the wave
front, tilted or not, changes by the amount of the aberration angle.
Hence a ground based telescope must be tilted by that angle, if the
photons are to fall straight down its sides.

In the case of a space based telescope moving in Earth's orbit, but
outside of Earth's pool of aether, the plane waves would reach the
telescope while still in the Sun's pool. However, the orbital velocity
of 18 miles/sec would still produce an aberration. The reason: once a
wavefront moved past the front of the telescope, a circular segment
would be sliced out of it. If the telescope were stationary while the
circular wave section moved down the barrel, the circular section would
pass intact out the bottom of the telescope, and into the eye of the
observer. If, however, the telescope is moving perpendicular to the
direction of movement of the incoming wave fronts at 18 miles/sec, which
is the speed of the Earth in its orbit, then all or part of each
sliced-out circular section will strike the side of the barrel before
reaching the bottom, unless the telescope barrel is tilted in accordance
with Tan^-1 (V1/V2). Only when it is so tilted will the circular wave
slices progress down the barrel without touching the sides.

--Mitchell Jones}***

Aether in the region where the Moon's field
is dominant will, of course, be dragged along by the Moon;

So why don't we see stars just before and just after
occultation by the Moon being displaced to the east?

***{Let's get concrete. Assume that the Moon is on the dark side of
Earth. The Earth and its entrained aether pool are moving along the
Earth's orbit at 18 miles/sec. The Moon is moving along parallel to them
at a speed of 18 miles/sec plus its orbital speed around the Earth,
which is about 2000 mph, or .555 miles/sec. Total speed of the Moon's
aether pool is thus 18.555 miles/sec. The aberration of a light beam
that enters the Moon's pool on the way to a ground based telescope on
Earth will be Tan^-1 (18.555/186000) = 5.7x10^-3 degrees, or 20.58
arcseconds, with the deviation being in the opposite direction of the
Moon's motion. But then, a fraction of a second later, the beam of light
will transit from its path in the Moon's pool to a new path in the
Earth's pool. In effect, the Earth's pool will be moving oppositely to
the Moon's motion in its orbit with a speed of .555 miles/sec, so the
aberration across that transition will be Tan^-1 (.555/186000) =
1.71x10^-4 degrees, or .62 arcseconds. This aberration will subtract
from the 20.58 arcsecond deviation that occurred when the beam entered
the Moon's pool, leaving a net deviation of 19.96 arcseconds, which is
exactly the same as the deviation that would have occurred if the
passage through the Moon's pool had not taken place. And that, of
course, is why we don't see lightpath deviations from stars when they
pass through the Moon's pool before entering the Earth's pool: the
aberration that occurs upon entering the pool is reversed when exiting
the pool. --MJ}***

Yes, my mistake, I was thinking of a sideways displacement
rather than a change of direction. The light would be moved
sideways but that would not be detectable (I think).

Star
*
|
|
( / -Moon- )
|
|

Earth

aether in the
region where the Sun's field is dominant will be dragged along by the
Sun; etc.

What this means is that there is no conceptual difference between the
passage of a beam of light from a star into an atmosphere of air which
is moving perpendicular to it at 18 miles/sec, and the passage of the
very same beam into an atmosphere of aether that is moving
perpendicular
to it at 18 miles/sec. In both cases, there will be a directional
aberration of 19.96 arcseconds for which ground based telescopes will
have to be adjusted, if they are to be centered on the star in
question.

Bottom line: stellar aberration is due to the mathematical relationship
between the speed of light and the component of motion of the telescope
perpendicular to the path of the light beam, irrespective of whether
the
telescope is immersed in an atmosphere of air, an atmosphere of air and
aether, or neither.

Your logic would require that you claim no aberration of a beam of
starlight passing into an atmosphere of air, since there is obviously
no
difference, conceptually, between that and the actual case where the
atmosphere is composed of both aether and air. I suspect, however, that
you make no such claim. :-)

The difference is that there is a shear at the atmospheric
boundary. For entry perpendicular to the surface I believe
aberration would be eliminated

***{No. Refraction would be eliminated, but the sort of aberration we
are discussing (stellar aberration) is due to the component of motion of
the receiver perpendicular to the previously established path of the
signal, and has nothing to do with the entry angle into the receiver. To
make that clear, suppose that a railway ore-car is sitting on a siding,
and a huge mass of dried Gillette Foamy shaving cream fills it to the
brim. Now imagine that a bowling ball is dropped straight down onto the
mass of dried shaving cream, with a velocity of 60 mph when it reaches
it. Result: it will cut a tunnel straight down into the shaving cream.
Next, imagine that the ore-car is moving at 60 mph when the bowling ball
falls into it. Result: the pathway cut through the foam by the bowling
ball will deviate from the original path in the amount of Tan^-1 (60/60)
= 45 degrees. That's the way aberration works, when the resistance of
the medium within the "receiver" is, for whatever reason, insufficient
to slow the speed of the moving object or wave.

Hold on, you are teating the light as a massive object
independent of the foam.

***{Yes. The plane waves are not mathematically continuous. Each is
composed to vast numbers of photons moving in parallel paths, and each
photon has an effective mass (not its rest mass) of hf/c^2. --MJ}***

In the aether model, light is
a transverse wave propagating through the foam.

***{You speak of "the aether model" as if there was ever a generalized
consensus regarding its characteristics. However, that has never been
the case. About the only thing all variants of aether theory had in
common was the idea of a transparent medium pervading all of space.
Everything else about it was hotly debated, and the same remains true
today, even though most people today are afraid of being laughed at if
they call the transparent medium in question by its proper name. Result:
they call it "the Dirac Sea," or "quantum foam," or "the zero-point
field," or "dark matter," etc. --MJ}***

In the
air above the car, the speed of sound is isotropic but
when it enters the foam in the moving car, the speed
becomes anisotropic. Your analogy doesn't illustrate
that.

***{Aberration doesn't arise from variations in wave speed in different
media, but from the velocity component of the receiver perpendicular to
the direction of the incoming photons. It is a purely mechanical
process, exactly like the process by which the bowling ball produces a
slanted tunnel when it falls into the moving mass of foam. --MJ}***

[snip]

George

************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ

On Feb 26, 10:27 am, Mitchell Jones wrote:
In article ,
"George Dishman" wrote:



"Mitchell Jones" wrote in message
...
In article ,
"George Dishman" wrote:
"Mitchell Jones" wrote in message
...
In article ,
"George Dishman" wrote:
...
For a gravitationally entrained aether, there should be
no aberration because the light is dragged along with
the aether which in turn is dragged by the Earth.

***{Incorrect. We are not talking about all the aether in the universe
being dragged along by the Earth. We are talking about only that
portion
which is in the region of the Earth's gravitational dominance being
dragged along by the Earth.

Right, and since the ligh't transverse motion realtive
to the earth is eliminated, so is aberration.

***{No. Aberration is a deviation in the pathway of a signal as it
passes into a "receiver," and is due to the component of motion of the
receiver perpendicular to the previously established path of the signal.

Right. Now as I understand the argument, the aether is moving
with the telescope so there is no transverse motion relative
to the receiver.

***{In the context of the gravitationally entrained aether theory, there
is no transverse motion relative to a ground-based telescope. However,
the telescope is not the "receiver," where the calculation of aberration
is concerned. The "receiver," instead, is the pool of aether entrained
by the Earth. The question at issue is whether the direction of the
incoming photons will be deviated in accordance with Tan^-1 (V1/V2)
when the wave that they comprise transitions from the Sun's pool to the
Earth's pool. --MJ}***

The magnitude of the deviation is Tan^-1 (V1/V2) where V1 is the
component of velocity of the receiver perpendicular to the previously
established signal pathway, and V2 is the velocity of the signal
relative to the external medium--i.e., the medium outside of the
receiver.

The "receiver," in the case we are discussing, is the pool of aether
entrained by the Earth,

I see the "receiver" as being the telescope itself.

***{There is obviously no aberration as the beam of light enters the
barrel of a ground-based telescope: there is no relative motion between
the telescope and the pool of aether entrained by the Earth.

You seem to be assuming that:
(a) the angular width of the patch of sky seen by a telescope
is 0 degrees. It isn't. Notice that in any telescope picture, there
appears more than one star. They have an angular separation.

(b) the fact that the same star can be seen at two different
seasons must mean it's at the same position in the sky. If there
is a small amount of aberration so that the star remains within
the same patch of sky, then it would show up in the telescope.
If there were a large enough aberration, you'd still see the
star by looking in a different direction.

Why do you think it's impossible to look in a different direction?

- Randy

In article .com,
" wrote:

On Feb 24, 4:12 am, "George Dishman" wrote:

[snip]

The observed amount of aberration is well
documented. What is in question is whether a dragged
aether predicts the obsereved aberration or not and my
take is that Maxwell's Equations would be the definitive
way to check that.

Yes, I am aware of Bradley's work which established that stellar
aberration exists. The experiment I was suggesting shows that a
dragged media could could account for the effect. You seemed
receptive to the idea, even suggesting what equipment should be used.
But now you want to revert to calculating a result. I'm not sure how
you intend to apply Maxwell's equations but would note that they are
in agreement with SR, and they were derived from a vortex aether
theory so they must be in agreement with that as well. If your
analysis some how comes up with the ather theory predicting a result
that differs from SR I would suggest looking at how things are defined
in the two theories. As I have previously shown the dragged aether
definiton of abberation provided by Mitchell Jones causes the two
theories to not agree.

***{There is a huge difference between a gravitationally entrained
aether theory and an aether drag theory. Drag would reflect a tendency
of matter, which is porous with respect to the aether, to carry some
aether along with it when it moves, in much the same way that a sponge,
when moved through the air, carries some air along with it.
Gravitational entrainment, however, arises because the aether has
gravitational mass, and, in the zone of gravitational dominance of a
celestial body, is carried along with the body in the same way that the
Earth carries its atmosphere along as it moves around the Sun. Drag is a
weak effect of the sort investigated by Fizeau, wherein there is a
constant flow of aether through the moving object that is dragging the
aether. In drag, aether pressure rises inside the moving object due to a
Bernoulli type of effect in which kinetic energy is converted into
pressure energy. Entrainment, on the other hand, is a strong effect: the
aether in the region of gravitational dominance of a body is attached to
the body, and, save in the outer reaches of that region, is not
exchanged with external aether. In drag, there is significant flow of
aether through the moving object; in entrainment, flow through the
object is negligible.

One of the things a gravitationally entrained aether theory predicts is
that Michelson-Morley type experiments will show a null result. There
was no aether wind in Michelson's lab because his lab was attached to
the Earth by gravity, and so was the aether in his lab. Hence there was
no relative motion between them. And, likewise, the gravitationally
entrained aether theory predicts a stellar aberration of up to 20
arcseconds, due to the component of motion of the Earth and its
entrained aether, of up to 18 miles/sec perpendicular to the direction
of the incoming starlight.

Regarding your suggested conflict with SR, please be specific.

--Mitchell Jones}***

[snip]


When different definitions are used the two theories can predict the
same result but not be in agreement on why those results are
observed. For SR there can be no aberation for two objects at rest in
the same frame. Period. End of story.

True and we are discussing whether dragged aether can explain
observed aberration so it is a given that the source and
observer must be in relative motion.

Tell that to Mitchell not me.

***{No need to tell it to me. I don't disagree with it. There is no
relative motion between the aether entrained by the Earth and a
ground-based telescope, and so there is no aberration when the lightpath
transitions into the barrel of the telescope. There is, however,
relative motion of up to 18 miles/sec between the pool of aether
gravitationally entrained by the Earth and the pool of aether
gravitationally entrained by the Sun. Result: across that transition, an
aberration in the lightpath of up to 20 arcseconds will occur. The
effect of this change in the lightpath angle, however, is the same as if
it had occurred as the light entered the telescope--to wit: the
telescope must be aligned along the aberrated lightpath, for best
viewing of the emitting object. --MJ}***

With the definition Mitchell
provided for aberation, and the method used for determining the path,
he ends up saying there is aberation but it is canceled out by drift.

***{No. The aberration is not canceled out by anything, and, because it
is not canceled out, ground-based telescopes have to be aligned along
the aberrated lightpath, if they are to have the best view of the
emitting object. All I am saying is that the aberration does not take
place as the light enters the telescope, but rather as it transitions
from the Sun's pool into the Earth's pool. In other words, there is an
angle between the lightpath in the Sun's pool and the lightpath in the
Earth's pool, in the amount of Tan^-1 (V1/V2), where V1 is the component
of velocity of the receiver (the Earth's pool) perpendicular to the
lightpath in the Sun's pool, and V2 is the speed of light. --MJ}***

There is no disagreement about what is observed but there is
disagreement about whether there is aberation or not because of the
different definitions.

I agree, aberration is observed but can a dragged aether
explain it? All the sources I have seen say no and my own
thoughts based on Huygens method tend to agree.

Read the above again. I said that using Mitchell's definition of
abberation his dragged aether theory predicts abberation even though
there is no relative motion between the source and receiver. Change
the definition of abberation to the same one used by SR and the
theories are in agreement.

Bruce

************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ

On Feb 25, 2:13 pm, "George Dishman" wrote:
wrote in message

oups.com...





On Feb 24, 4:12 am, "George Dishman" wrote:
wrote in message
groups.com...
On Feb 23, 8:56 am, "George Dishman" wrote:
wrote in message
groups.com...
...
If you want to get precise you could use a sound beam. You can ame
a
beam of sound at someone 100 meters away and the person standing
next
to them wont hear a thing.

http://www.meyersound.com/support/pa...g/figure_3.jpg

Interesting, however sound is a longitudinal wave so
I'm always sceptical of those analogies. If I wanted
accuracy I would use Maxwell's Equations which were
intended for EM and should be equally applicable to
an aether theory.

Considering that Maxwell's equations were derived from aether theory I
am sure they would work perfectly, so long as they are properly
applied. But we weren't talking about calculating a result. We were
talking about doing an actual experiment to see if predictions matched
up with with observed results.

I don't agree, I think the experiment has already been
done first by Bradley in the 1850s IIRC and recently by
Hipparcos. The observed amount of aberration is well
documented. What is in question is whether a dragged
aether predicts the obsereved aberration or not and my
take is that Maxwell's Equations would be the definitive
way to check that.

Yes, I am aware of Bradley's work which established that stellar
aberration exists. The experiment I was suggesting shows that a
dragged media could could account for the effect. You seemed
receptive to the idea, even suggesting what equipment should be used.
But now you want to revert to calculating a result.

What I was saying was that I felt a slightly different
experiment would be needed to simulate it, EM waves are
transverse and we need a sliding boundary so the
alternative I suggested seemed closer and perhaps
feasible although still not perfect. However, I still
maintain that to test a theory, you make a prediction
using that theory and compare against actual observation.
The observations already exist so I really see no need to
try to duplicate them with a poorer equivalent when we
know the result from the real thing.

And it was my contention that improper analysis of how signals travel
through a medium could be revealed by examining how sound travels
through air. As you have said, the observations already exist, so
what we need to determine is if the theory can account for the
observations. I am saying the classical analysis uses the wrong path
for the signal. Correct that error and the predictions agree with
observations.

I'm not sure how
you intend to apply Maxwell's equations

I guess take a distant point source and see how the waves
propagate through the boundary. The hard part would be
detailing how the aether was represented

but would note that they are
in agreement with SR, and they were derived from a vortex aether
theory so they must be in agreement with that as well.

Well as I understand it, only an un-dragged Lorentzian
aether is fully compatible with SR so some differences
should show up using a dragged Galilean aether. The
question would be whether there is a difference in this
particular observation. For example there is no difference
in the MMx so perhaps that could apply here too.

Maxwell was not using Lorentzian aether when he developed his
equations, and I would assume that a "vortex aether" would involve
some dragging. That would suggest that if there was any
incompatability between the aether theory and SR, Maxwell's equations
would not reveal it.

If your
analysis some how comes up with the ather theory predicting a result
that differs from SR I would suggest looking at how things are defined
in the two theories. As I have previously shown the dragged aether
definiton of abberation provided by Mitchell Jones causes the two
theories to not agree.

I agree you have to be careful to use the same quantity
in each but that's another question. What I suggested at
the start was that I believe it is understood generally
that a dragged aether would not be compatible with the
observation of stellar aberration and that's as far as I
would go.

And I think you believe that due to incorrect annalysis of what
dragged aether theory predicts.





With aether theory you don't know the
rest frame of the aether. It could be fully dragged, partially
dragged, or not dragged at all as in LET. At least with air we know
what its state of motion is, and we can work with speeds that are a
fair fraction of the speed of sound.

My reason for suggesting the "sound beam" was because it could be
accurately aimed and the sound path could be plotted. Step a few feet
off to either side of the path and you would hear nothing.

OK, if you wanted to do that I would suggest you use two
crystals and launch a transverse (shear) wave into one.

Tx
========
|
v
|
========

Then add a second crystal below with a detector Rx fixed
to the opposite face

Tx
========
|
v first crystal at rest
|
========
|
v --- second crystal in motion
|
========
Rx

The second crystal must be in motion relative to the first.
Now the trick is predict what happens at the boundary
between the crystals bearing in mind it is a transverse
wave. I think that's difficult and probably not intuitive.

Last time I checked I wasn't living inside a crystal

According to aether theory you were To support transverse
waves, you need such a material and with very specific
properties.

Sound in air
may not be a perfect analogy but I think it is closer to the aether
than a solid crystal.

Air cannot support transverse waves at all.

And crystals do not allow planets to pass through.





I get the impression that Mitchell Jones is a supporter of an aether
theory. His definition of aberation uses a path defined by the rest
frame of the medium. There is no way that he can get results based
on
that definition to agree with SR.

He doesn't need to, he needs to get it to agree with
observed aberration. Of course the same theory might
then fail other tests but that's not the topic ;-)

When different definitions are used the two theories can predict the
same result but not be in agreement on why those results are
observed. For SR there can be no aberation for two objects at rest in
the same frame. Period. End of story.

True and we are discussing whether dragged aether can explain
observed aberration so it is a given that the source and
observer must be in relative motion.

Tell that to Mitchell not me.

I was just agreeing with you. Observed aberration is due to
the varying velocity of the Earth in orbit as you know and
that is what his dragged aether must explain.

With the definition Mitchell
provided for aberation, and the method used for determining the path,
he ends up saying there is aberation but it is canceled out by drift.
There is no disagreement about what is observed but there is
disagreement about whether there is aberation or not because of the
different definitions.

I agree, aberration is observed but can a dragged aether
explain it? All the sources I have seen say no and my own
thoughts based on Huygens method tend to agree.

Read the above again. I said that using Mitchell's definition of
abberation his dragged aether theory predicts abberation even though
there is no relative motion between the source and receiver.

That would be another problem but harder to test.

Change
the definition of abberation to the same one used by SR and the
theories are in agreement.

My understanding is that dragged aether predicts no
aberration when in fact we observe it, that was the
original point. SR certainly gets it right so I think
their predictions differ.

On Feb 26, 2:38 pm, Mitchell Jones wrote:
In article .com,

" wrote:
On Feb 24, 4:12 am, "George Dishman" wrote:

[snip]





The observed amount of aberration is well
documented. What is in question is whether a dragged
aether predicts the obsereved aberration or not and my
take is that Maxwell's Equations would be the definitive
way to check that.

Yes, I am aware of Bradley's work which established that stellar
aberration exists. The experiment I was suggesting shows that a
dragged media could could account for the effect. You seemed
receptive to the idea, even suggesting what equipment should be used.
But now you want to revert to calculating a result. I'm not sure how
you intend to apply Maxwell's equations but would note that they are
in agreement with SR, and they were derived from a vortex aether
theory so they must be in agreement with that as well. If your
analysis some how comes up with the ather theory predicting a result
that differs from SR I would suggest looking at how things are defined
in the two theories. As I have previously shown the dragged aether
definiton of abberation provided by Mitchell Jones causes the two
theories to not agree.

***{There is a huge difference between a gravitationally entrained
aether theory and an aether drag theory. Drag would reflect a tendency
of matter, which is porous with respect to the aether, to carry some
aether along with it when it moves, in much the same way that a sponge,
when moved through the air, carries some air along with it.
Gravitational entrainment, however, arises because the aether has
gravitational mass, and, in the zone of gravitational dominance of a
celestial body, is carried along with the body in the same way that the
Earth carries its atmosphere along as it moves around the Sun. Drag is a
weak effect of the sort investigated by Fizeau, wherein there is a
constant flow of aether through the moving object that is dragging the
aether. In drag, aether pressure rises inside the moving object due to a
Bernoulli type of effect in which kinetic energy is converted into
pressure energy. Entrainment, on the other hand, is a strong effect: the
aether in the region of gravitational dominance of a body is attached to
the body, and, save in the outer reaches of that region, is not
exchanged with external aether. In drag, there is significant flow of
aether through the moving object; in entrainment, flow through the
object is negligible.

You are just talking a matter of degree between no drag and full
drag. I say that either one and any in between can account for
abberation.

One of the things a gravitationally entrained aether theory predicts is
that Michelson-Morley type experiments will show a null result. There
was no aether wind in Michelson's lab because his lab was attached to
the Earth by gravity, and so was the aether in his lab. Hence there was
no relative motion between them. And, likewise, the gravitationally
entrained aether theory predicts a stellar aberration of up to 20
arcseconds, due to the component of motion of the Earth and its
entrained aether, of up to 18 miles/sec perpendicular to the direction
of the incoming starlight.

Regarding your suggested conflict with SR, please be specific.

--Mitchell Jones}***

SR says that the path from the emitter to the receiver is a straight
line. The abberation angle shows up due to the relative motion
between the emitter and receiver. Your analysis shows a kink in the
signal's path when it crosses a boundry.

[snip]



When different definitions are used the two theories can predict the
same result but not be in agreement on why those results are
observed. For SR there can be no aberation for two objects at rest in
the same frame. Period. End of story.

True and we are discussing whether dragged aether can explain
observed aberration so it is a given that the source and
observer must be in relative motion.

Tell that to Mitchell not me.

***{No need to tell it to me. I don't disagree with it. There is no
relative motion between the aether entrained by the Earth and a
ground-based telescope, and so there is no aberration when the lightpath
transitions into the barrel of the telescope. There is, however,
relative motion of up to 18 miles/sec between the pool of aether
gravitationally entrained by the Earth and the pool of aether
gravitationally entrained by the Sun. Result: across that transition, an
aberration in the lightpath of up to 20 arcseconds will occur. The
effect of this change in the lightpath angle, however, is the same as if
it had occurred as the light entered the telescope--to wit: the
telescope must be aligned along the aberrated lightpath, for best
viewing of the emitting object. --MJ}***

My comments were about two stationary observers with the medium
passing perpendicular to the sight line between them. You predicted a
signal path coming from down wind and that wind drift canceled the
abberation. SR says the signal path is the same as the sight line.

With the definition Mitchell
provided for aberation, and the method used for determining the path,
he ends up saying there is aberation but it is canceled out by drift.

***{No. The aberration is not canceled out by anything, and, because it
is not canceled out, ground-based telescopes have to be aligned along
the aberrated lightpath, if they are to have the best view of the
emitting object. All I am saying is that the aberration does not take
place as the light enters the telescope, but rather as it transitions
from the Sun's pool into the Earth's pool. In other words, there is an
angle between the lightpath in the Sun's pool and the lightpath in the
Earth's pool, in the amount of Tan^-1 (V1/V2), where V1 is the component
of velocity of the receiver (the Earth's pool) perpendicular to the
lightpath in the Sun's pool, and V2 is the speed of light. --MJ}***

There is no disagreement about what is observed but there is
disagreement about whether there is aberation or not because of the
different definitions.

I agree, aberration is observed but can a dragged aether
explain it? All the sources I have seen say no and my own
thoughts based on Huygens method tend to agree.

Read the above again. I said that using Mitchell's definition of
abberation his dragged aether theory predicts abberation even though
there is no relative motion between the source and receiver. Change
the definition of abberation to the same one used by SR and the
theories are in agreement.

Bruce

************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ- Hide quoted text -

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