Isotropic and anisotropic propagation of light

[Aether]

It must be worrying that scientists (Silvertooth, DeWitte, Navia and Augusto, see http://arxiv.org/PS_cache/astro-ph/pdf/0604/0604145.pdf ) are reporting anisotropy in the one-way speed of light of around 400km/s, which is the Earth’s velocity relative to the CMB.

More evidence: - Michelson-Morley Experiments Revisited and the Cosmic Background Radiation Preferred Frame. Cahill re-analysis of the old results (1887) from the Michelson-Morley interferometer experiment that was designed to detect absolute motion, and reveals an absolute speed of the Earth of v=359+/-54 km/s, which is in excellent agreement with the speed of v=365+/-18 km/s determined from the dipole fit, in 1991, to the NASA COBE satellite Cosmic Background Radiation (CBR) observations.
http://www.arxiv.org/abs/physics/0205065

I wrote a paper on this subject last year and showed it to Reg Cahill. He made some suggestions, and after I addressed those within the paper he personally endorsed me at arxiv.org to post papers there. The paper discusses an experiment that I am preparing to carry out myself, and I'll post it when I have some definitive results.

Now, you and I both know that M-M experiments are two-way experiments, right? So why are you connecting this subject to one-way experiments?

 

[Hans de Vries]

More evidence: - Michelson-Morley Experiments Revisited and the Cosmic Background Radiation Preferred Frame. Cahill re-analysis of the old results (1887) from the Michelson-Morley interferometer experiment that was designed to detect absolute motion, and reveals an absolute speed of the Earth of v=359+/-54 km/s,

How can anyone believe this at all. Such huge relative deviations (>0.1%)
translate to errors of circa 40 km in the Global Positioning System which
would have to be corrected continuously every 24 hours when the Earth
rotates around its axis.

Regards, Hans

 

[Aether]

How can anyone believe this at all. Such huge relative deviations (>0.1%)
translate to errors of circa 40 km in the Global Positioning System which
would have to be corrected continuously every 24 hours when the Earth
rotates around its axis.

Regards, Hans

GPS satellites orbit at an altitude of 20,200km, so the fraction of time that the signal is propagating in "gas mode" through the atmosphere is relatively small. Also, the proposed effect is of second-order.

 

[clj4]

What is worrying is that clj4 actually seems to buy the experimental results described in the Navia paper, and insists that where the authors went wrong is in their claim that said results are inconsistent with SR.

No, I am not "buying" the Navia paper, quite the opposite I pointed out that it is most likely a hoax. So, please stop your lamentable diversions.
When you run out of scientific arguments you start resorting to outright lies? Are you getting that desperate ? See here, in this thread, my first answer to the Navia "masterpiece":

https://www.physicsforums.com/showpost.php?p=958066&postcount=17

One-way speed of light anisotropy is never going to be "formally verified" as it is a mathematical concept in the first place rather than a physical concept. There are consequences for relativity, or at least for most people's concept of what relativity actually is, but these have always been there. What is at stake in future experiments is local Lorentz symmetry.

Repeating the same lies do not make them into scientific truth. You have been given ample proof to the opposite. About 11 papers (and growing) on the subject. From reputable scientists, published in top tier journals.

 

[Hans de Vries]

GPS satellites orbit at an altitude of 20,200km, so the fraction of time that the signal is propagating in "gas mode" through the atmosphere is relatively small. Also, the proposed effect is of second-order.

Well, looking at this paper,

Reginald T. Cahill claims that the MM experiment can be used after all
to measure the absolute motion through the aether, it however should
be done in a medium with a refractive index higher than 1.00 (vacuum)

He then claims that he can read the absolute speed through the aether
from MM's 1887 (120 year old) experiment because it was done in air
with a refractive index of 1.00029.

According to Cahill, the effect becomes more visible with \sqrt{n-1}
Why doesn't he just put the simplest MM setup in water which makes
it more than 30 times more sensitive as in air. Even the simplest
table-top experiment would reveal the absolute speed with better
than 1% accuracy.

Running LIGO without a vacuum would measure the absolute speed
with what? one-in-a-million? one-in-a-billion?
http://www.ligo.caltech.edu/docs/G/G040436-00/G040436-00.ppt

Aether, please don't let me waste my time with reading this stuff.


Regards, Hans

 

[clj4]

More evidence: - Michelson-Morley Experiments Revisited and the Cosmic Background Radiation Preferred Frame. Cahill re-analysis of the old results (1887) from the Michelson-Morley interferometer experiment that was designed to detect absolute motion, and reveals an absolute speed of the Earth of v=359+/-54 km/s, which is in excellent agreement with the speed of v=365+/-18 km/s determined from the dipole fit, in 1991, to the NASA COBE satellite Cosmic Background Radiation (CBR) observations.
http://www.arxiv.org/abs/physics/0205065

Reg Cahill is known as a kook, I will be surprised if his paper made it into any reputable journal. Here is a list of his "masterpieces":

http://www.scieng.flinders.edu.au/cpes/people/cahill_r/processphysics.html

"The Process Physics group and collaborators are conducting various experiments including new designs for absolute motion detectors; these include novel interferometer experiments and coaxial cable propagation-time experiments. The main aim of these experiments is the systematic study of the gravitational waves of the new theory of gravity. These have already been detected in the experiments by Miller, Torr and Kolen, and DeWitte."

 

[clj4]

I wrote a paper on this subject last year and showed it to Reg Cahill. He made some suggestions, and after I addressed those within the paper he personally endorsed me at arxiv.org to post papers there. The paper discusses an experiment that I am preparing to carry out myself, and I'll post it when I have some definitive results.

Now, you and I both know that M-M experiments are two-way experiments, right? So why are you connecting this subject to one-way experiments?

Yes, Reg Cahill is a well known antirelativist kook, so what did you expect ? Of course he endorsed your paper.You got the "seal of approval" from a nut. It doesn't mean anything.

 

[wisp]

Even the simplest table-top experiment would reveal the absolute speed with better than 1% accuracy.

Aether, please don't let me waste my time with reading this stuff.

Regards, Hans

Hans. I won't was your time discussing this with you but someone has done this simple water test, see: -

[Quack link deleted]

 

[JustinLevy]

Wisp and Aether,
SR has been proven quite well in many many tests. Please stop bringing debates of this into many relativity discussions. If you are going to complain about experimental proof of SR, please make one topic devoted to this, and keep the complaints in this topic.


In regards to Aethers comment: One-way speed of light anisotropy is never going to be \"formally verified\" as it is a mathematical concept in the first place rather than a physical concept.

This may be techincally true (I am not sure why clj4 is denying it), but that does not make SR incorrect as you are reading into it too much. I have already commented on this here:
https://www.physicsforums.com/showpost.php?p=968985&postcount=75

Do you agree with that?
So in effort to prevent everyone from arguing about two different things:


Clj4, do you agree that GR allows us to use any coordinate systems and even the speed of light is not invarient when considering general coordinate transformations?

Aether, do you understand that this does not mean SR is wrong, as SR is only applicable in inertial frames?



To this question Aether originally answered: I am not claiming here that SR is wrong.
But you now appear to have changed your mind? Please clarify.
And clj4 must have overlooked the question, maybe he can clarify his position as well.

You two should really agree what you are arguing about before continuing on for more and more posts.

 

[Aether]

In regards to Aethers comment: One-way speed of light anisotropy is never going to be \"formally verified\" as it is a mathematical concept in the first place rather than a physical concept.

This may be techincally true (I am not sure why clj4 is denying it), but that does not make SR incorrect as you are reading into it too much. I have already commented on this here:
https://www.physicsforums.com/showpost.php?p=968985&postcount=75

Do you agree with that?

No objection.

Aether, do you understand that this does not mean SR is wrong, as SR is only applicable in inertial frames?

Yes. My point is that it is coordinate-system dependent, and when that dependency is accounted for we may perform experiments to test local Lorentz invariance.

To this question Aether originally answered: I am not claiming here that SR is wrong.
But you now appear to have changed your mind? Please clarify.

I haven't changed my mind. To what exactly are you referring?

 

[ZapperZ]

Hans. I won't was your time discussing this with you but someone has done this simple water test, see: -

1. You refused to show where the cahill paper has been published. It means that you don't care if such a thing has been accepted as a valid enough paper in a peer-reviewed journal.

2. You are now citing someone's personal cranky website as "evidence" for such a thing.

You obviously do not consider the PF Guidelines as something that applies to you.

Zz.

 

[clj4]

Well, looking at this paper,

Reginald T. Cahill claims that the MM experiment can be used after all
to measure the absolute motion through the aether, it however should
be done in a medium with a refractive index higher than 1.00 (vacuum)

He then claims that he can read the absolute speed through the aether
from MM's 1887 (120 year old) experiment because it was done in air
with a refractive index of 1.00029.

According to Cahill, the effect becomes more visible with \sqrt{n-1}
Why doesn't he just put the simplest MM setup in water which makes
it more than 30 times more sensitive as in air. Even the simplest
table-top experiment would reveal the absolute speed with better
than 1% accuracy.

Running LIGO without a vacuum would measure the absolute speed
with what? one-in-a-million? one-in-a-billion?
http://www.ligo.caltech.edu/docs/G/G040436-00/G040436-00.ppt

Aether, please don't let me waste my time with reading this stuff.Regards, Hans

Hans and ZapperZ

The "paper" cited by "Aether" would be a perfect example of physics fraud.
It is a beatiful case to set in front of the graduate students and let them have at it.
It should be a new thread, since it was thrown in by "Aether" as a diversion from the OWLS discussion.
Here are a few points to start the new thread (ZapperZ , can you move this in a new thread?)

1. As both of you have asked: how come that no one has tried a MMX experiment in a medium with refrigency higher than 1? Well, there have been at least TWO such experiments, by reputed scientists with...NULL results:

[1]Shamir and Fox, N. Cim. 62B no. 2 (1969), p258.
A repetition of the MMX with the optical paths in perspex (n = 1.49), and a laser-based optics sensitive to ~0.00003 fringe. They report a null result with an upper limit on V_aether of 6.64 km/s.

[2]Trimmer et al., Phys. Rev. D8, p3321 (1973); Phys. Rev. D9 p2489 (1974).
A triangle interferometer with one leg in glass. They set an upper limit on the anisotropy of 0.025 m/s. This is about one-millionth of the Earth's orbital velocity and about 1/10,000 of its rotational velocity.

So, "Aether" may be working on yet another such experiment. The result (if the experiment is not going to be forged) should be null, contradicting Cahill. Kind of strange that Cahill wrote his paper in 2002 but did not do any experiment. He seemed content to fake the explanation of the MM and Miller experiments.

2. What is the deal with the Reg Cahill paper?
Aside from being a well known kook, his paper is dead wrong. Can you spot the error? Hint: the light speed in the moving refringent medium is not c/n when calculated wrt to the CMBR frame. Cahill does not understand the elementary speed composition! He doesn't even understand the old Fizeau law for speed of light in moving bodies (which agrees with the relativistic explanation!)

3. How about "Aether's" recent follow-up on the Cahill paper? (see post 61). I think I found it here:

http://arxiv.org/ftp/physics/papers/0603/0603267.pdf

It is nothing less than an attempt to resurect the long dead "Lorentz-FitzGerald contraction", the long dead 1904 Lorentz theory.

We should really separate this from the current thread. On the other hand, should we even discuss kooky theories?

 

[wisp]

You obviously do not consider the PF Guidelines as something that applies to you.
Zz.

OK, I’ll try and stick with papers that have been published in a peer-reviewed journal, but it limits the scope to be able to challenge mainstream views.

 

[wisp]

Re: clj4 link
****
http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&...


Test of the isotropy of the one-way speed of light using hydrogen-maser frequency standards
Timothy P. Krisher, Lute Maleki, George F. Lutes, Lori E. Primas, Ronald T. Logan, and John D. Anderson
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109
Clifford M. Will
McDonnell Center for the Space Sciences, Department of Physics, Washington University, St. Louis, Missouri 63130
Received 25 September 1989
A new test of the isotropy of the one-way velocity of light has been performed using NASA’s Deep Space Network (DSN). During five rotations of the Earth, we compared the phases of two hydrogen-maser frequency standards separated by 21 km using an ultrastable fiber optics link. Because of the unique design of the experiment, it is possible to derive independent limits on anisotropies that are linear and quadratic in the velocity of the Earth with respect to a preferred frame. Assuming that the anisotropies have not been partially canceled by systematic environmental effects on the instrumentation, the best limits that can be inferred from the data are Δc/c<3.5×10-7 and Δc/c<2×10-8 for linear and quadratic dependencies, respectively, on the velocity of the Earth with respect to the cosmic microwave background. The theoretical interpretation of the experiment is discussed.

****

Why don’t physicists write in plain English? What exactly are they saying here?

I understand this as: - They tested for a variation in the one-way speed of light and reported a negative result.
But this negative result was only with respect to the cosmic microwave radiation (CMR) frame. Do they not want to report the variation in the one-way speed of light in the earth-frame in which their test equipment resides?

What was the point in stating an upper limit on the one-way linear anisotropy of 100 m/s for an earth-based test, when the limit only applies to a frame moving at 400km/s relative to the earth?
If the CMR is an ether frame, then all they are saying is that light moves at constant speed through the ether.

 

[ZapperZ]

OK, I’ll try and stick with papers that have been published in a peer-reviewed journal, but it limits the scope to be able to challenge mainstream views.

Well tough! That's the rule you have agreed to. Would you like me to quote some crackpot website to challenge YOUR views?

Zz.

 

[clj4]

Re: clj4 link
****
http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&...Test of the isotropy of the one-way speed of light using hydrogen-maser frequency standards
Timothy P. Krisher, Lute Maleki, George F. Lutes, Lori E. Primas, Ronald T. Logan, and John D. Anderson
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109
Clifford M. Will
McDonnell Center for the Space Sciences, Department of Physics, Washington University, St. Louis, Missouri 63130
Received 25 September 1989
A new test of the isotropy of the one-way velocity of light has been performed using NASA’s Deep Space Network (DSN). During five rotations of the Earth, we compared the phases of two hydrogen-maser frequency standards separated by 21 km using an ultrastable fiber optics link. Because of the unique design of the experiment, it is possible to derive independent limits on anisotropies that are linear and quadratic in the velocity of the Earth with respect to a preferred frame. Assuming that the anisotropies have not been partially canceled by systematic environmental effects on the instrumentation, the best limits that can be inferred from the data are Δc/c<3.5×10-7 and Δc/c<2×10-8 for linear and quadratic dependencies, respectively, on the velocity of the Earth with respect to the cosmic microwave background. The theoretical interpretation of the experiment is discussed.

****

Why don’t physicists write in plain English? What exactly are they saying here?

I understand this as: - They tested for a variation in the one-way speed of light and reported a negative result.
But this negative result was only with respect to the cosmic microwave radiation (CMR) frame. Do they not want to report the variation in the one-way speed of light in the earth-frame in which their test equipment resides?

What was the point in stating an upper limit on the one-way linear anisotropy of 100 m/s for an earth-based test, when the limit only applies to a frame moving at 400km/s relative to the earth?
If the CMR is an ether frame, then all they are saying is that light moves at constant speed through the ether.

You are understanding it incorrectly. Your bias prevents you from understanding it. Tough.

 

[Aether]

Re: clj4 link
****
http://prola.aps.org/abstract/PRD/v42/i2/p731_1?qid=6c4ab66eee46e0e8&...


Test of the isotropy of the one-way speed of light using hydrogen-maser frequency standards
Timothy P. Krisher, Lute Maleki, George F. Lutes, Lori E. Primas, Ronald T. Logan, and John D. Anderson
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109
Clifford M. Will
McDonnell Center for the Space Sciences, Department of Physics, Washington University, St. Louis, Missouri 63130
Received 25 September 1989
A new test of the isotropy of the one-way velocity of light has been performed using NASA’s Deep Space Network (DSN). During five rotations of the Earth, we compared the phases of two hydrogen-maser frequency standards separated by 21 km using an ultrastable fiber optics link. Because of the unique design of the experiment, it is possible to derive independent limits on anisotropies that are linear and quadratic in the velocity of the Earth with respect to a preferred frame. Assuming that the anisotropies have not been partially canceled by systematic environmental effects on the instrumentation, the best limits that can be inferred from the data are Δc/c<3.5×10-7 and Δc/c<2×10-8 for linear and quadratic dependencies, respectively, on the velocity of the Earth with respect to the cosmic microwave background. The theoretical interpretation of the experiment is discussed.

****

Why don’t physicists write in plain English? What exactly are they saying here?

I understand this as: - They tested for a variation in the one-way speed of light and reported a negative result.
But this negative result was only with respect to the cosmic microwave radiation (CMR) frame. Do they not want to report the variation in the one-way speed of light in the earth-frame in which their test equipment resides?

What was the point in stating an upper limit on the one-way linear anisotropy of 100 m/s for an earth-based test, when the limit only applies to a frame moving at 400km/s relative to the earth?
If the CMR is an ether frame, then all they are saying is that light moves at constant speed through the ether.

Do you have a copy of the paper, or are you only looking at the abstract? The paper describes a series of measurements made in the laboratory frame, and their analysis boils this down to the more concise statements made in the abstract. Their claim about "measuring" the "one-way speed of light" is coordinate-system dependent, and needlessly confusing. What they actually "measure" is the Mansouri-Sexl parameter \alpha.

 

[clj4]

Do you have a copy of the paper, or are you only looking at the abstract? The paper describes a series of measurements made in the laboratory frame, and their analysis boils this down to the more concise statements made in the abstract. Their claim about "measuring" the "one-way speed of light" is coordinate-system dependent, and needlessly confusing. What they actually "measure" is the Mansouri-Sexl parameter \alpha.

You don't understand what you read either. In addition , you willfully and shamelessly distort what the authors say, the authors never claim to be "measuring" the "one-way speed of light" Here is exactly what they say:

"A new test of the isotropy of the one-way velocity of light has been performed using NASA’s Deep Space Network (DSN)."

ISOTROPY, this is what they measured (more exactly they put constraint bars on ANISOTROPY). For a while I thought I was discussing with a person interested in scientific truth. Not after I found out what you stand for in your web page:

http://levynewphysics.com/

You are not here to discuss science, you are here to push your anti-science, antirelativistic views.

 

[Aether]

You don't understand what you read either. In addition , you willfully and shamelessly distort what the authors say, the authors never claim to be "measuring" the "one-way speed of light" Here is exactly what they say:

"A new test of the isotropy of the one-way velocity of light has been performed using NASA’s Deep Space Network (DSN)."

ISOTROPY, this is what they measured (more exactly they put constraint bars on ANISOTROPY).

Ok, their claim about "measuring" the "isotropy of the one-way velocity of light" is coordinate-system dependent, and needlessly confusing. What they are actually trying to "measure" is the Mansouri-Sexl parameter \alpha.

For a while I thought I was discussing with a person interested in scientific truth. Not after I found out what you stand for in your web page:

http://levynewphysics.com/

You are not here to discuss science, you are here to push your anti-science, antirelativistic views.

This isn't my web page. I've never seen it before.

 

[wisp]

You don't understand what you read either... the authors never claim to be "measuring" the "one-way speed of light" Here is exactly what they say:

"A new test of the isotropy of the one-way velocity of light has been performed using NASA’s Deep Space Network (DSN)."

ISOTROPY, this is what they measured (more exactly they put constraint bars on ANISOTROPY).

Thanks for your reply in defining the purpose of this test – it’s as clear as mud.
This is confusing. If you look up the definitions of ISOTROPY, ISOTROPIC, ANISOTROPIC, ANISOTROPY they are defined as: -

http://en.wikipedia.org/wiki/Isotropic

http://www.pcmag.com/encyclopedia_term/0,2542,t=isotropic&i=45480,00.asp

Isotropic: Definition of: isotropic
Refers to properties, such as transmission speed, that are the same regardless of the direction that is measured. Contrast with anisotropic.

Definition of: anisotropic :-
Refers to properties, such as transmission speed, that vary depending on the direction of measurement. Contrast with isotropic.

So to sum up – This test doesn’t measure the one-way speed of light (your words).

 

[wisp]

Some clj4 quotes

#13

Secondly, contrary to what you think, one way speed of light has been measured repeatedly to be equal to c INDEPENDENT of the RELATIVE movement of the observer and the source.

#21

The third paper, while it only "suggests" a means of executing one way light speed measurements looks awfully close in approach to the one way experiment of Gagnon.

Obviously there’s confusion in the wording used. So for the benefit of all, can anyone explain in plain English explain what the difference are between the two statements: -

1) Experiments that measure variations in the one-way speed of light
2) Experiments that measure anisotropy in the one-way speed of light.

 

[clj4]

Ok, their claim about "measuring" the "isotropy of the one-way velocity of light" is coordinate-system dependent, and needlessly confusing. What they are actually trying to "measure" is the Mansouri-Sexl parameter \alpha.

This isn't my web page. I've never seen it before.

..and neither is this "masterpiece" of antirelativism that you are boasting about here:

https://www.physicsforums.com/showpost.php?p=970766&postcount=61

The one that is collecting dust at arxiv.org:

http://arxiv.org/ftp/physics/papers/0603/0603267.pdf

The one endorsed by Reg Cahill.

 

[Aether]

..and neither is this "masterpiece" of antirelativism that you are boasting about here:

https://www.physicsforums.com/showpost.php?p=970766&postcount=61

Correct.

The one that is collecting dust at arxiv.org:

http://arxiv.org/ftp/physics/papers/0603/0603267.pdf

The one endorsed by Reg Cahill.

This is not my paper. I'll offer to make my paper on this subject immediately available to Zz, pervect, JesseM, Hurkyl, Tom Mattson, or Garth (sorry if I left anyone out) if any or all of them want to help referee it. Btw, this subject has nothing at all to do with my own personal theory that I have mentioned; it is simply an opportunity to do some interesting experiments out of my own pocket.

 

[clj4]

Correct.

This is not my paper. I'll offer to make my paper on this subject immediately available to Zz, pervect, JesseM, Hurkyl, Tom Mattson, or Garth (sorry if I left anyone out) if any or all of them want to help referee it. Btw, this subject has nothing at all to do with my own personal theory that I have mentioned; it is simply an opportunity to do some interesting experiments out of my own pocket.

Yes, you missed me.I'll have a look at it.

 

[quantumdude]

Aether,

If you've written a paper that you'd like to discuss but that hasn't been peer-reviewed you can send it to the IR Forum, where it will go into a moderation queue. Anyone who wears the "PF Admin", "PF Mentor", or "Science Advisor" emblems will be able to review it. All of the people on your list fall into one of those categories.

 

[Aether]

Aether,

If you've written a paper that you'd like to discuss but that hasn't been peer-reviewed you can send it to the IR Forum, where it will go into a moderation queue. Anyone who wears the "PF Admin", "PF Mentor", or "Science Advisor" emblems will be able to review it. All of the people on your list fall into one of those categories.

Thank-you, Tom. I know that, and appreciate the availability of the IR forum. I'm preparing to actually carry out some experiments, and don't want to post my paper in public before I have actual results to share. Is there any way to post the paper, get feedback, and delay public viewing until a later time?

 

[quantumdude]

The only way is to send it to IR and then correspond with the reviewers. It can be held in the moderation queue indefinitely.

 

[Aether]

The only way is to send it to IR and then correspond with the reviewers.

Thanks. I'll review my paper for compliance with IR guidelines, and then drop it into the moderation queue.

It can be held in the moderation queue indefinitely.

No doubt!

 

[quantumdude]

No doubt!

I'm just saying, we advertise a turnaround time of 30 days for action to be taken on IR threads. I didn't want you to think that we would automatically make your paper public after that time. We'll hold it as long as you want.

 

[clj4]

I'm just saying, we advertise a turnaround time of 30 days for action to be taken on IR threads. I didn't want you to think that we would automatically make your paper public after that time. We'll hold it as long as you want.

Aether,
I promise a turnaround of 1 day. If it is correct, I will say so. If it is wrong, you know by now that I can spot errors very fast.