Could 80-year-old ether experiments have detected a cosmological temperature gradient?

February 8, 2016 by Lisa Zyga feature
ether
Design of a modern ether-drift experiment, in which the light frequencies from two lasers in perpendicular directions are compared at a beat note detector. Credit: M. Consoli, et al. ©2016 EPLA

(Phys.org)—In a new study, scientists have proposed that tiny residual effects measured by ether-drift experiments in the 1920s and '30s may be the first evidence of a temperature gradient that was theorized in the 1970s, but never before detected in a laboratory. The theorized temperature gradient is thought to be caused by the solar system moving at 370 km/sec through the cosmic background radiation (CBR), which is the faint electromagnetic radiation that fills the universe.

The researchers, Maurizio Consoli from INFN, along with Alessandro Pluchino and Andrea Rapisarda from INFN and the University of Catania in Italy, have published a paper on their reinterpretation of the ether-drift experiments in a recent issue of EPL.

"The main significance of our work is that those small residual effects found in all ether-drift experiments in gaseous systems, usually considered as uninteresting thermal disturbances, might instead represent the first experimental evidence for the Earth's within the CBR," Consoli told Phys.org.

"The interest of our work is twofold. On the one hand, there is an important historical interest because these small effects were obtained well before the discovery of the CBR (in 1965 by Penzias and Wilson, Astrophys. J. Lett. 142 (1965) 419) and well before the observation of the Earth's motion within the CBR (in 1977 by Smoot, Gorenstein and Muller, Phys. Rev. Lett. 39 (1977) 898, with the U2 experiment). On the other hand, the agreement between optical measurements in a laboratory and direct measurements of the CBR in space would indicate how powerful optical interferometers can be."

Background

In the 19th century, one of the most controversial questions in science was whether empty space was truly empty like a vacuum or whether it contained a medium known as ether. Ether had been proposed as a medium through which light waves could travel, since light's wave-like properties had recently been discovered, and it was believed that all waves needed some kind of medium to propagate through.

The first crucial experiment to provide evidence that ether does not exist as classically predicted came in 1887, when Michelson and Morley famously showed that light travels at the same speed in the perpendicular arms of an interferometer. If ether existed—and if it behaved as expected—it would be predicted to slow light down more in one direction than in the perpendicular direction, since motion through the ether is "anisotropic," or directionally dependent.

According to Consoli, Pluchino, and Rapisarda, however, the Michelson-Morley experiment did not yield a strictly null result because of its limited precision. The classically predicted effect of ether-drift was 10-8, while the Michelson-Morley experiment had a precision of 10-9—precise enough to rule out the classically predicted effect, but hazy enough to leave some room for the possibility of a smaller-than-expected effect.

In the years since, 20 or so similar experiments have been performed that further increased the precision, with the most recent test achieving the highest precision yet of 10-18 just last year (M. Nagel et al., Nature Comm. 6 (2015) 8174).

Scientists performing these tests today aren't as interested in disproving the existence of ether as they are in validating the foundations of Einstein's theory of special relativity. A difference in the speed of light in any two perpendicular directions in an inertial reference frame would contradict special relativity, since relativity requires a vacuum within which the speed of light is constant. Many important concepts emerge from this fact, including that the universe has no preferred reference frame, that there is no absolute space or time, and that you can never really tell for sure whether you are at rest or in constant motion since all motion is relative.

A matter of interpretation

At first glance, the 20 or so experiments performed since 1887 seem to have steadily improved the precision in support of the view that there is no ether and no preferred reference frame.

However, not all the results were perfectly unambiguous. In particular, Dayton Miller's 1933 optical interferometer experiment detected so-called "fringe shifts," which were much smaller than any expected effect but large enough to be considered non-negligible. To make things more complicated, these residual effects were irregular and not consistently reproducible.

At the time, the fringe shifts were written off to temperature differences inside the lab, since fluctuations of even a tiny fraction of a degree could have caused the observations. However, Miller disagreed with this interpretation. He argued that his measurements could not be explained by uniform heating, only by some non-uniform, directional effect.

Miller's experiment was not the only one to detect unexpectedly tiny effects. As Consoli and Pluchino, together with Caroline Matheson at the University of Cambridge, showed in a previous paper (Eur. Phys. J. Plus 128 (2013) 71 and arXiv:1302.3508 [physics.gen-ph]), all of the ether-drift experiments that were performed in gaseous media (either air or helium), including the original Michelson-Morley experiment, detected very small residual effects that were generally ignored.

In their new paper, the researchers argue that all of these residual effects may provide the first indirect evidence of the temperature anisotropy caused by the Earth's motion within the CBR. Previous direct observations of the CBR in space found that the entire solar system is moving at a velocity of about 370 km/sec toward a specific point in the sky, creating a "kinematic dipole," which is basically a Doppler effect. As a consequence, "an observer moving through the CBR would see different temperatures in different directions," as the researchers explain in their paper. But so far no study has actually measured in a laboratory the predicted caused by the solar system's movement.

The scientists explained that the temperature gradient is universal in the sense that all observers moving within the CBR (even hypothetical observers living on distant planets) will see a qualitatively similar effect. However, the quantitative aspects are different and depend on the particular state of motion of each planet and its surroundings.

"This motion is called 'peculiar' because it is characteristic of our local position in the universe," Pluchino said. "In fact, it is obtained by combining the motion of our galaxy, and of the local group of galaxies, with a velocity of about 600 km/sec toward what is called the Great Attractor (a large concentration of matter situated at about 100 Mpc from us), along with the motion of the solar system within our galaxy. Therefore, an observer placed at the opposite site of our galaxy will also see a dipole anisotropy but, for him, the kinematical parameters will be different."

By analyzing the data from the interferometer experiments in gaseous systems, the researchers found that all of the residual effects produced velocities in good agreement with the theoretical velocity of 370 km/sec.

"The average Miller fringe shift was giving exactly the same observable velocity as in Michelson-Morley," Pluchino said. "Therefore, the standard thermal interpretation of Miller's data is only acceptable if this temperature effect has a non-local origin, i.e., it does not depend on the particular conditions of its laboratory."

The scientists explain that the reason why this temperature effect and velocity had not been noticed before now is because their new interpretation is based on relativity.

"The basic difference with the standard point of view is that one should correctly reinterpret the observations according to relativity and not just use the (incorrect) classical formulas," Pluchino said.

The researchers also addressed the question of why not all of the ether-drift experiments detected fringe shifts, only those performed in gaseous media. As technology progressed over the decades, researchers carried out the experiments in different media, such as a vacuum or solid dielectrics. Traditionally, researchers have thought that the experiments were all testing the same thing, regardless of the medium.

But the Italian scientists think otherwise. If their proposal is correct, then the CBR temperature gradient would affect gaseous systems more strongly than others because the weakly bound gas molecules can be set in motion more easily by a thermal gradient than the molecules in a solid, which would not be expected to move very much. And in the case of a vacuum, a temperature gradient would have no matter to act on at all.

Implications

The scientists suggest that their interpretation could be tested by a new generation of precise laser interferometers, which like the early experiments could attempt to detect small differences in the speed of light between perpendicular directions in a gaseous medium. This type of experiment would provide a much more precise test than those of the '20s and '30s, and even more precise than the most recent test in a gaseous medium, which was performed in the '60s (which also detected residual time variations that the scientists show are consistent with the new interpretation).

If future experiments detect the expected signal, it would have far-reaching consequences on everything from physics to biology.

"If this temperature gradient could be definitely confirmed in a laboratory, it would mean that everything on Earth (and on any other celestial body moving through the CBR) is exposed to a tiny energy flow," Consoli said. "This flow is now very weak but, in the past, was substantially stronger when the CBR temperature was higher. Therefore, it has represented (and still represents) a sort of background noise which is independent of any localized source. It is known that such non-equilibrium condition can induce (or it could have induced) forms of self-organization in matter. Therefore, our result could also be relevant for those research areas which look for the origin of complexity in nature."

What do the results mean for special relativity?

"Clearly, the whole analysis uses a relativistic formalism," Consoli said. "But the final picture is different from standard . In fact, the temperature gradient due to the Earth's motion within the CBR can affect a weakly bound gaseous matter and, therefore, the velocity of light propagating inside it. Small differences in perpendicular directions can thus be detected with an interferometer. In this way, with measurements performed entirely inside a laboratory, one could distinguish between a state of rest and a state of uniform motion. This is not too surprising since the CBR was not known in 1905."

Rather than speculate on this area, the researchers prefer to focus on more practical implications.

"Our findings emphasize the power of optical interferometry in a laboratory," Consoli said. "This could give precious, complementary information to the direct observations of the CBR in space."

Explore further: Special relativity from first principles

More information: M. Consoli, et al. "Cosmic Background Radiation and 'ether-drift' experiments." EPL. DOI: 10.1209/0295-5075/113/19001 . Also at arXiv:1601.06518 [astro-ph.CO]

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Phys1
4.2 / 5 (12) Feb 08, 2016
"As a consequence, "an observer moving through the CBR would see different temperatures in different directions," as the researchers explain in their paper."
If this is true then the CBR represents an absolute reference frame !
antialias_physorg
4.6 / 5 (11) Feb 08, 2016
"If this temperature gradient could be definitely confirmed in a laboratory, it would mean that everything on Earth (and on any other celestial body moving through the CBR) is exposed to a tiny energy flow,"

Hmmm...CBR power generators anyone? (Just kidding. the resulting power flow would be astronomically small)
Graeme
4.6 / 5 (5) Feb 08, 2016
There would be a far higher difference in radiation from the Earth and the sky, which would totally mask a millikelvin difference in CMB. But I suppose someone can check that experiment out again.
dirk_bruere
3.6 / 5 (5) Feb 08, 2016
Would the effect still show up if the apparatus was shielded from microwaves?
Eikka
4.3 / 5 (11) Feb 08, 2016
If this is true then the CBR represents an absolute reference frame !


No more than waves on an ocean tell a ship where it is.

The photons of the microwave background radiation are conceptually no different from a cloud of interstellar dust that you're flying through. Colliding with the CBR doesn't tell you how it is moving or where in space it is in absolute terms - only in terms relative to you.

Using the CBR as a reference frame would be like saying "Take the third hurricane to the left from Barbados".
billpress11
2.8 / 5 (4) Feb 08, 2016
This is what has always puzzled me, Einstein stated that motion does not add or subtract from the speed of light. If that is true why wouldn't there be a slight difference in the background temperature of the CMB if we are moving relative to it? If the CBR frequency is increased or decreased ever so slightly by the earth's motion through it shouldn't we also measure as a slight increase or decrease in the temperature of the CBR that we would measure?
Phys1
3.1 / 5 (7) Feb 08, 2016
@Eikka
If the CMBR appears differently in function of the speed of an "observer moving through" then the CMBR sets an absolute reference frame.
No more than waves on an ocean tell a ship where it is.

The comparison fails for at least two reasons. The waves can tell you how _fast_ the ship is. In the case of the CMBR the waves have constant speed independent of the speed of the observer.
Zorcon
3 / 5 (10) Feb 08, 2016
"As a consequence, "an observer moving through the CBR would see different temperatures in different directions," as the researchers explain in their paper."
If this is true then the CBR represents an absolute reference frame !

But not necessarily a universal one. It would provide an absolute reference frame with respect to the observable universe from the time of recombination though (unless or until some violation of special relativity turns up!).
Zorcon
2.9 / 5 (8) Feb 08, 2016
This is what has always puzzled me, Einstein stated that motion does not add or subtract from the speed of light. If that is true why wouldn't there be a slight difference in the background temperature of the CMB if we are moving relative to it? If the CBR frequency is increased or decreased ever so slightly by the earth's motion through it shouldn't we also measure as a slight increase or decrease in the temperature of the CBR that we would measure?

Doppler shift.
Phys1
3.7 / 5 (6) Feb 08, 2016
continued
In fact the local group moves with 600 km/s with respect to the CMBR.
This means that the CMBR sets an absolute velocity reference frame
when I believed velocity was relative.
Phys1
3.7 / 5 (6) Feb 08, 2016
continued
As there is an absolute rest frame SR all of a sudden seems less self evident.
billpress11
3.3 / 5 (7) Feb 08, 2016
This is what has always puzzled me, Einstein stated that motion does not add or subtract from the speed of light. If that is true why wouldn't there be a slight difference in the background temperature of the CMB if we are moving relative to it? If the CBR frequency is increased or decreased ever so slightly by the earth's motion through it shouldn't we also measure as a slight increase or decrease in the temperature of the CBR that we would measure?

Doppler shift.

Isn't that exactly what would create a slight increase in the temperature in the forward direction of motion? And increase in frequency should increase the temperature observed shouldn't it?
Torbjorn_Larsson_OM
4.6 / 5 (11) Feb 08, 2016
"It is known that such non-equilibrium condition can induce (or it could have induced) forms of self-organization in matter. Therefore, our result could also be relevant for those research areas which look for the origin of complexity in nature.""

Not likely, the huge non-equilibrium from a planet orbiting a star in the HZ would drown it out re geology, biology et cetera.

@Phys1: Physicists doesn't count the CMB rest frame (which is what the article describes) as an *absolute* reference frame because it is not given by relativity but is a relativistic rest frame among others.

Cf if the universe had been rotating then the effect would have not set up an absolute spin frame, or the value of the electron mass or charge which are also not absolute mass or charge references as the values could have been different, et cetera.

But like the GPS satellite system it can set up a useful reference frame.
promile
Feb 08, 2016
This comment has been removed by a moderator.
promile
Feb 08, 2016
This comment has been removed by a moderator.
Phys1
3.9 / 5 (7) Feb 08, 2016
@TLOM
The rest frame of the universe, sounds pretty absolute to me.
if the universe had been rotating

linear motion is relative and has no absolute meaning (until this afternoon).
Rotation however is absolute.
Phys1
3.9 / 5 (7) Feb 08, 2016
This is what has always puzzled me, Einstein stated that motion does not add or subtract from the speed of light. If that is true why wouldn't there be a slight difference in the background temperature of the CMB if we are moving relative to it? If the CBR frequency is increased or decreased ever so slightly by the earth's motion through it shouldn't we also measure as a slight increase or decrease in the temperature of the CBR that we would measure?

Doppler shift.

Isn't that exactly what would create a slight increase in the temperature in the forward direction of motion? And increase in frequency should increase the temperature observed shouldn't it?

Yes.
https://en.wikipe...ack_body
Phys1
3.2 / 5 (9) Feb 08, 2016
@promile
You may not care ;-) , but I took you off the list for your comments.
Enough physics there.
promile
Feb 08, 2016
This comment has been removed by a moderator.
Zorcon
3.3 / 5 (10) Feb 08, 2016
continued
As there is an absolute rest frame SR all of a sudden seems less self evident.

There is still no evidence for an absolute rest frame.

*IF* one exists, there is no reason to suppose the local portion of the universe was at rest when the CBR was emitted. So the CMBR we observe only provides a local rest frame.

You could call it an "absolute rest frame with respect to that portion of the universe from the time of recombination, that we can observe" but why? A qualified "absolute" is no longer absolute and has no bearing on SR.

The observable portion of the CBR also varies with time. The horizon grew faster than the expansion for billions of years, so our sample now encompasses many orders of magnitude more than it would have at CBR emission. In the distant future everything not gravitationally bound will recede past the horizon. So your "absolute" frame also varies with time.

I would love to see an exception to SR (new physics!). But this isn't it.
promile
Feb 08, 2016
This comment has been removed by a moderator.
Phys1
3.6 / 5 (7) Feb 08, 2016
continued
As there is an absolute rest frame SR all of a sudden seems less self evident.

There is still no evidence for an absolute rest frame.

The CBR sets a velocity reference in my opinion.
Why do you say that is this not an absolute reference?

*IF* one exists, there is no reason to suppose the local portion of the universe was at rest when the CBR was emitted. So the CMBR we observe only provides a local rest frame.

That is correct, but the definition of a reference frame does not require that.
I agree that this does in no way contradict SR, but it makes SR even less intuitive.
AGreatWhopper
3.4 / 5 (9) Feb 08, 2016
Physicists used to scoff at psychology papers because they "start with error variance", the idea being that many main effects are tiny signals in the residual variance. I knew one researcher once that used to say, "Error variance??? That's my universe!"

That was often cited as why so many of the best statisticians work in the soft sciences. The idea was that solid physics has such nice clear main effects that you don't need advanced stat to tease out a relationship.

No longer. "Publish or perish" has overtaken even the hard sciences.
vlaaing peerd
3 / 5 (1) Feb 09, 2016
hm surprisingly sensible comments in an article that mentions ether.

I'm interested in what Phys already remarked. It appears to me you can indeed use it as an absolute frame of reference and independently measure the velocity of any object in the universe from it.

This should be a problem with Einstein stating there is no absolute frame of reference.

So, does anyone have an idea what I'm missing?
promile
Feb 09, 2016
This comment has been removed by a moderator.
antialias_physorg
5 / 5 (4) Feb 09, 2016
The idea was that solid physics has such nice clear main effects that you don't need advanced stat to tease out a relationship.

Really? That idea must be 100 years old. Advanced statistical analyses are at the core of all sciences - and have been for a very long time.

And it's not really surprising, because the effects that can be seen with the naked eye and are "clearly X or Y" have long ago been observed and published. Anyone who thinks that they're going to just take a cursory glance at something and immediately 'intuit' some new knowledge from that are just kidding themselves.
promile
Feb 09, 2016
This comment has been removed by a moderator.
Uncle Ira
3.2 / 5 (11) Feb 09, 2016
Anyone who thinks that they're going to just take a cursory glance at something and immediately 'intuit' some new knowledge from that are just kidding themselves.


There is a lot of peoples here at the physorg just kidding around with them selfs (and kidding around with all the rest of us too.)
Mike_Massen
2.5 / 5 (11) Feb 09, 2016
Uncle Ira says
.. lot of peoples here at the physorg just kidding around with them selfs (and kidding around with all the rest of us too)
ie. You mindlessly copy old google links defame me & fail checking those making claims were real, they are only dumb nicknames just like you who make many ugly claims ?

Why Uncle Ira, can't you prove any claims & attack me personally ?

ie.
1. ebay account closed due to theft ?
2. False testimonials about my products ?
3. many "whiny" emails ?
4. Script bugs compiling profiles of comment activity ?
5. "Mental" reminding you made big mistakes, proven yet you Fail to apologise ?

Who's the irrational personality & hides behind a facile manipulative nickname ?

Own up Uncle Ira, you made mistakes, post facile odd humor with "skippy/cher" & evidently have comprehension errors & cognitive deficits/drunk ?

Who's insane; he who stalks making ugly false claims to try to put me down or he who only defends ?

Defamation <> Honorable !
Mike_Massen
2.6 / 5 (10) Feb 09, 2016
Zorcon offers
There is still no evidence for an absolute rest frame
Concretely concur & leads me to raise Q re potential possibility of an initial angular momentum at earliest point re BB origin in any/all our accepted dimensions - wondering if there is way to ascertain methodology to determine if evidence there was none at all & if so with what level of uncertainty & if there is likely symmetry re all 3D rotational modes & how one might craft a suitable filter/experiment, even at our singular location, to delineate such information from a mostly singular reference point comparatively - ie Since we only have CMBR observations so very local to our own reference frame @ Earth ?

FWIW: See you are new here, letting you know, have a long standing dispute with odd ball posters; likes of Uncle Ira, antigoracle, bluehigh, Benni, bschott & few others that only act prejudicially to try to diminish & distract from useful Physics dialectic, thanks for fresh approach, cheers
Uncle Ira
3 / 5 (8) Feb 10, 2016
Mike the Skippy says,

Uncle Ira blah, blah, blah and a few more blahs, and I am just too cool for the school and everybody stop what they are doing and look at me blah, blah and a few more blahs for good measured


Well Mike-Skippy, Ira's world is not all about you. But you sure do seem to enjoy my attentions, otherwise why would you take every opportunity to show us your mental conditions?

Now don't get jealous, but I got out way ahead of you on that super analyzing computer program to use on the foolishment on the physorg stuffs. I fed him with your foolishments and he told me that the group I fed in had a Borderline Personality Disorder, and a Narcissistic Personality Disorder, and a Histrionic Disorder, and a Bipolar Personality Disorder too.

When I told him it was not a group but just one Skippy, he told me I had one really sick Skippy, maybe a meth-head-Skippy.

Now what? You going to write some more emails to the physorg? Take me to court again?
Uncle Ira
3 / 5 (8) Feb 10, 2016
P.S. for Mike the Skippy.

I almost forget. Why you don't put on your silly looking pointy cap and pipe down Skippy. The last few days days and some more today I been really busy with school kids' radio club. It's the annual School Club Roundup and I volunteer to help them. So if you want to fool around with me you will have to settle for just a few minutes here or there for now.

Laissez les bons temps rouler P'tit Couyon. (That's coonass for: "Little Fool, that silly looking pointy cap sure looking good on you.")
gkam
2.3 / 5 (9) Feb 10, 2016
"Why Uncle Ira, can't you prove any claims & attack me personally ?"
--------------------------------------

It is all he has. Remember how he calls this "The Uncle Ira Show"? He plays these silly games and thinks he is outsmarting somebody.

Apparently, he is unaware of Twitter, made for him and high-schools all over the nation.
Eikka
not rated yet Feb 16, 2016
The comparison fails for at least two reasons. The waves can tell you how _fast_ the ship is. In the case of the CMBR the waves have constant speed independent of the speed of the observer.


Constant speed relative to what?

A ship on an ocean can't tell its own speed from the waves because it can't know how fast the waves are going relative to land. It may be riding an ocean current, which means the actual propagation speed of the waves is undefined without further reference.

Of course you can use the CBR as a local reference, but not as an absolute reference because you'd have to invent a "land" to act as a stationary backdrop of space to tell that you're moving in the absolute sense.
Hyperfuzzy
not rated yet Feb 17, 2016
How do you compensate for the non-linear medium? i.e 1st order, 3rd order, 5th order, ... then polarization, atomic polarization, ... don't forget the existing "body" field of the planet, etc. See potential energy and kinetic energy of QM, without the misconception. Or is it hypnotism from looking into a mirror? So yea, we can always be more precise. The lack of precision only proves the lack of precision. We would have to peel away all local before we get to the universal. You need the fields of each particle and it's motion, etc..

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