Talk:Michelson–Morley experiment/Archive 3

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The effect of the air

An anonymous IP user, 131.230.58.249, has twice introduced the following edit, justifying the edit on the basis of a non-peer-reviewed source:

"It is believed that the medium of Michelson-Morley experiment is actually the air. The speed of the air with respect of the experiment device is actually zero. No matter when and where we repeat the Michelson-Morley experiment in atmosphere, we can never observe the movement of interference fringe."
— Luo, Siwei (2012). "The Model of Wave Propagation in Classical Physics". Progress in Electromagnetics Research Symposium (Moscow).

I am sorry to say that your "air-dragging hypothesis", like the aether-dragging hypothesis, has unacceptable observational consequences that were very well understood in 1887, which is why nobody except for you, then or now, has ever brought it up as a possible explanation.

  1. The air-dragging hypothesis is completely inconsistent with the phenomenon of stellar aberration.
  2. The air-dragging hypothesis is completely inconsistent with the results of the Fizeau experiment. The air-dragging hypothesis predicts a dragging coefficient of 1.
  3. Fibre optic gyroscopes were, of course, unknown in 1887. However, if light is dragged by matter in the fashion in which you believe, then it is impossible for fibre optic gyroscopes to work.

There have been many repeats of the Fizeau experiment. The results of a repeat of the Fizeau experiment in 1988 using a ring resonator verified that the Fizeau drag coefficient equals 1-1/n2 to within ±2.8×10-4. See G. A. Sanders and S. Ezekiel, Measurement of Fresnel drag in moving media using a ring-resonator technique. JOSA B, Vol. 5, Issue 3, pp. 674-678 (1988) http://dx.doi.org/10.1364/JOSAB.5.000674

Stigmatella aurantiaca (talk) 02:06, 21 February 2013 (UTC)

  1. The air-dragging hypothesis describes light propagating in medium that has dragging effect.While stellar aberration is the phenomenon that light propagation with the moving source which has no dragging effect and wave velocity does not change. Stellar aberration is a doppler effect and in this situation wave velocity does not change.
  2. Based on Fizeau experiment, the medium water has dragging coefficient of 1. As for air, I don't think we can detect whether dragging coefficient is 1 or 1-1/n2, since compared with light velocity in the air, the velocity of air is quite small, which is negligible.
  3. Light velocity in fibre optic gyroscope is c/n. If light is dragged by matter, which means light velocity should be c/n+v (if the velocity of matter is v, and dragging coefficient is 1), rather than v.

Since the velocity of air with respect to apparatus is zero, time that light propagate at two different paths is the same 2nl/c, that is why when the apparatus is rotated by 90°, there is no movement of interference fringe. — Preceding unsigned comment added by Siwei Pi Luo (talk • contribs) 01:55, 22 February 2013 (UTC)

Off-topic discussion about subject
Your air-dragging hypothesis can explain the negative outcome of a Michelson-Morley experiment conducted in the air. However, your air-dragging hypothesis is inconsistent with the phenomenon of stellar aberration.
I do not believe that you understand the incompatibility of your air-dragging hypotheses with the phenomenon of stellar aberration. I have created a simple animation for you to contemplate.
Stellar aberration occurs when the observer's velocity has a component that is perpendicular to the line traveled by the light incoming from the star. As seen in the animation on the left, the telescope must be tilted before the star will appear in the center of the eyepiece. If your air-dragging hypothesis were true, then stellar aberration would not occur because the light would be dragged by the air which would be moving along with the telescope. As seen in the animation on the right, if the atmosphere drags light, then the telescope must be pointed directly at the star for the star to appear in the center of the eyepiece.
P.S. To sign your name, use four tildes in a row, i.e. ~~~~
I will continue tomorrow with discussion of the Fizeau experiment. Stigmatella aurantiaca (talk) 07:26, 22 February 2013 (UTC)

Admittedly, stellar aberration is a good point to discuss the dragging coefficient of air is 1 or 1-1/n2. While the observation of stellar aberration is likely be affected by many factors and the angel is not that obvious to determine dragging coefficient of air. I cite the following reading in stellar aberration, "Observations of such a star were made difficult by the limited field of view of Bradley and Molyneux's telescope, and the lack of suitable stars of sufficient brightness. One such star, however, with a right ascension nearly equal to that of γ Draconis, but in the opposite sense, was selected and kept under observation. This star was seen to possess an apparent motion similar to that which would be a consequence of the nutation of the Earth's axis; but since its declination varied only one half as much as in the case of γ Draconis, it was obvious that nutation did not supply the requisite solution. Whether the motion was due to an irregular distribution of the Earth's atmosphere, thus involving abnormal variations in the refractive index, was also investigated; here, again, negative results were obtained."

While if you can provide some more strict experiment designing and more precise results of experiments, I think it would be much better to discuss. The main argument is about how much the dragging coefficient of air is. If there is some experiments that can strictly tell the dragging coefficient of air, then I think it is more convincing and reliable.Siwei Pi Luo (talk) 16:49, 22 February 2013 (UTC)

For air, 1-1/n2 = 5.5×10−4. The difference between 1 and 5.5×10−4 is quite immense. The measured aberration of light indicates a value for the dragging coefficient MUCH closer to 5.5×10−4 than to 1. A dragging coefficient of 1 would indicate an inability to measure any stellar aberration at all. Stigmatella aurantiaca (talk) 19:25, 22 February 2013 (UTC)

Since based on Fizeau experiment it is really hard to accelerate air to a high velocity which is comparable to light. As far as my knowledge, it is difficult to conclude it is 1 or 0. For example, assume the velocity of air is 1000 m/s , the velocity light propagating in air in Fizeau experiment is 3*10^8+1000 m/s or 3*10^8-1000 m/s (if dragging coefficient is 1), and this difference is hard to be detected by experiment apparatus. If this difference is not detected by apparatus, then it would conclude dragging coefficient is close to zero which is likely to be 1-1/n2.By the way, it is difficult to accelerate the air to 1000m/s. I doubt that dragging coefficient is 1-1/n2, because in other medium like water, dragging coefficient is 1, however, in other medium like air it become another value. I mean it is likely to be consistent to all the medium. If it is 1, then for all the medium it should be 1. If it is 1-1/n2, also for all the medium it should be 1-1/n2 including water. Siwei Pi Luo (talk) 20:52, 22 February 2013 (UTC)Siwei Pi Luo (talk) 21:05, 22 February 2013 (UTC)

Meanwhile, I think Stellar aberration can also be an evidence of air dragging. Your animation reveals that if there is air dragging, apparent position of a star is not its true position. Siwei Pi Luo (talk) 21:20, 22 February 2013 (UTC)

Sorry, you have things backwards. If there is air dragging, the apparent position of a star overhead WILL BE its true position. It is EASY to tell the difference between a dragging coefficient of 1 versus a dragging coefficient of 0. A value of 1 means complete dragging. A value of 0 means no dragging.
Your explanation for the MMX results requires that the dragging coefficient be 1, or close to 1. Instead, the dragging coefficient is close to zero. Stigmatella aurantiaca (talk) 21:46, 22 February 2013 (UTC)

I beg if you assume dragging coefficient is 1, your results in fizeau experiment are still satisfied, since experiment apparatus can not detect growth of light velocity. Siwei Pi Luo (talk) 22:03, 22 February 2013 (UTC)

Based on your animation, apparent position of a star is not its true position. The star can be seen as static. apparent position is along the line of observation. Siwei Pi Luo (talk) 22:02, 22 February 2013 (UTC)

In Fizeau experiment, for example, if the velocity of air is 1000 m/s. Yes I assume dragging coefficient is 1. The velocity of light in this experiment is 3*10^8+1000 m/s(or 3*10^8-1000m/s), the issue is that normally experiment apparatus can not tell whether it is 3*10^8+1000 m/s or 3*10^8 m/s, since 1000m/s compared with light speed is negligible. In addition, experiment apparatus can not tell the difference, so it is easily to get the conclusion that light velocity in apparatus is still 3*10^8 m/s, rather than 3*10^8+1000 m/s. And then conclude dragging coefficient is 0. This is doubtable and inconvincing.

You need to imagine the stars as being infinitely far away, so that when the telescope is pointed at right angles to the ground, it is pointed directly at the star.
A dragging coefficient of 1 means complete dragging, extremely easy to measure. It doesn't make sense for you to say that air has a dragging coefficient of 1 but that it is difficult to measure. Stigmatella aurantiaca (talk) 22:10, 22 February 2013 (UTC)

It is difficult to measure, because experimental method to measure light velocity can not exactly to tell whether it is 3*10^8 m/s or 3*10^8+1000 m/s. By the way, if the air can be accelerate to a comparable velocity, then the result would be clear, like it is easy to tell whether it is 3*10^8 m/s or 3*10^8 +1*10^6 m/s. Siwei Pi Luo (talk) 22:24, 22 February 2013 (UTC)

I image the stars as being infinitely far away. And after observation, observer will treat it as along the line he observe. So the apparent position of stars are not their true position. Siwei Pi Luo (talk) 22:35, 22 February 2013 (UTC)

Interferometric methods are extremely sensitive, and assuming a dragging coefficient of 1, the difference between 3*10^8 m/s or 3*10^8+1000 m/s would be trivial to measure in a first order experiment. You can't have it both ways. You can't assume a dragging coefficient of 1, and then turn around and argue with me that since the dragging coefficient is exceedingly tiny, it would be impossible to measure accurately. Your air-dragging hypothesis REQUIRES a dragging coefficient of 1, and such a number is DIRECTLY CONTRADICTED by observation and experiment. Stigmatella aurantiaca (talk) 23:40, 22 February 2013 (UTC)

Let me put it in this way, assume dragging coefficient is 1, but we can not observe interference fringe move in Fizeau experiment, and then it is easily to conclude that the medium has no dragging effect and dragging coefficient is close to zero. After that, it is easy to beg the question that dragging coefficient is 1-1/n2.

The reason that it is hard to observe interference fringe move in Fizeau experiment is light velocity is too large compared with the velocity of air. If the velocity of air is big enough, then we may observe interfernece fringe move in Fizeau experiment, then we will realize how much dragging coefficient is. Siwei Pi Luo (talk) 23:49, 22 February 2013 (UTC)

With the result of Fizeau experiment so far, it is not sufficient to claim whether dragging coefficient is 1 or 1-1/n2. However, I trend to believe it is 1. Because this property of electromengetics wave is likely to keep consistent in all isotropic medium.Siwei Pi Luo (talk) 23:53, 22 February 2013 (UTC)

You are not being logical. A dragging coefficient of 1 would be trivial to observe in the Fizeau experiment. In fact, the dragging coefficient of air is close to zero. Therefore, air-dragging cannot be invoked as an explanation of the MMX null result. Stigmatella aurantiaca (talk) 23:59, 22 February 2013 (UTC)

If the velocity of air is big enough, indeed, I think it would be easy to observe in the Fizeau experiment. But in reality, the velocity of air is too small, compared with light, it is almost zero. So do you think this result is really reliable. Extremely speaking, if the medium is static with respect to apparatus, we can not observe the movement of interference fringe in Fizeau experiment, then can we conclude that dragging coefficient is 0?Siwei Pi Luo (talk) 00:06, 23 February 2013 (UTC)

And Michelson-Morley experiment null result is the evidence that dragging coefficient of air is 1.Siwei Pi Luo (talk) 00:29, 23 February 2013 (UTC)

It is quite pointless to keep up this argument if you don't have a reliable secondary source that explains your POV. Dicklyon (talk) 00:37, 23 February 2013 (UTC)

I know it is pointless to keep up this argument. I just wanna share knowledge and ideas in wiki, but was blocked. Siwei Pi Luo (talk) 00:45, 23 February 2013 (UTC)

...and you will continue to be blocked. I am by no means the only person monitoring this article for misguided contributions.
Now, this thing that you have about the dragging coefficient of air. Fizeau established that the dragging coefficient of air is certainly less than 0.025.(Fizeau, 1860) In the one-and-a-half centuries since Fizeau conducted his experiment, his experiment has been repeated many times with steadily increasing refinement, such that currently, his formula for the dragging coefficient has been validated to parts-per-ten-thousand over a range of materials of widely differing refractive index, from gases in a ring laser to rotating silica disks, and over a wide range of wavelengths of light.(for example, see Bilger and Stowell, 1977; Jones, 1972; Sanders and Ezekiel, 1988) There are, for excellent reasons, absolutely no serious proposals that air may have sufficient dragging effect so as to explain the MMX experiment. Stigmatella aurantiaca (talk) 06:04, 23 February 2013 (UTC)

So what? The medium velocity is not big enough. No matter how many times it repeat, they can not observe movement of interference. And it does not sufficiently support the conclusion. And based on contunity of electrical field and magnetic field, dragging coefficient may be calculated mathematically. Siwei Pi Luo (talk) 15:04, 23 February 2013 (UTC)

  1. Non-observance of interference fringe shift in the Fizeau experiment is evidence that the dragging coefficient must be very small.
  2. Large ring laser gyroscopes can measure rotation rates of 1×10-10 rad/sec over modest integration times, which would be impossible if the dragging coefficient of the gases used in the laser were 1. Over extended integration times in the hundreds of hours range, they can measure rotation rates in the 10-14 rad/sec range. The measured beat frequencies agree with theoretical computations to better than one part in 10-5. The major uncertainties in these measurements have to do with such mundane effects as changes in ground tilt, temperature variations and the like.
  3. There are plenty of references online that you use to can verify these statements of mine. You could start with Large Laser Gyroscopes for Monitoring Earth Rotation and go from there. Basically, there is NO EVIDENCE that the gases used in a ring laser gyroscope drag light by an amount significantly different than the amount calculated by Fizeau's formula. Stigmatella aurantiaca (talk) 16:15, 23 February 2013 (UTC)

The gases velocity is not large enough. Siwei Pi Luo (talk) 17:09, 23 February 2013 (UTC)

You are in a state of denial. I don't think you even know how ring laser gyros work. Look them up. What you are trying to say is that there is something strange and unique going on with the MMX experiment that cannot be independently verified with any other experiment. It doesn't matter to you that modern day re-enactmentments of the MMX experiment are performed in high vacuum using technologies that were unavailable in Michelson's day. You are totally focused on your own ad hoc explanation of the MMX results, an "explanation" that, for good reasons, was not considered even remotely viable in 1887, and which would not be accepted by any other anti-relativist today. Stigmatella aurantiaca (talk) 19:04, 23 February 2013 (UTC)

Ring laser gyroscope is a very good example to support glass dragging coefficient is 1. I cite the calculation in Sagnac effect:

If dragging coefficient is zero, then

and the statment "Under this metric, the speed of light tangent to the ring is depending on whether the light is moving against or with the rotation of the ring." in Sagnac effect .Siwei Pi Luo (talk) 23:15, 23 February 2013 (UTC)Siwei Pi Luo (talk) 23:16, 23 February 2013 (UTC)

  1. The Sagnac effect works because light is always propagated in empty space with a definite velocity [speed] c which is independent of the state of motion of the emitting body. In other words, the Sagnac effect works because of Einstein's original statement of the second postulate, which is as true in classical mechanics as it is true for special relativity. It is only various popularized restatements of the second postulate that are inconsistent with classical mechanics. (For an interesting discussion of common misconceptions about what Einstein did or did not state in his second postulate, see Baierlein(2006).)
  2. You've placed a twist on this by proposing that the Sagnac effect works because light is propagated in air with speed c/n (n ≈ 1.000293 at STP for 589.29 nm light) with respect to the air.
  3. When you write, "t1 = t2 = 2πR/c", all are you are doing is stating that the operation of the Sagnac interferometer is inconsistent with certain variants of emission theory.
  4. In a fibre optic gyro, the fibers rotate along with the source. If the dragging coefficient of the glass were 1, then the speed of light tangent to the ring would be c/n ± Rω and the time to travel around one circuit would be a constant 2πRn/c regardless whether the light is going against or with the rotation of the ring.
  5. In other words, the operation of a fibre optic gyro is inconsistent with the notion that light is dragged by the glass fibers with dragging coefficient 1.
  6. In a ring laser gyro, the gas-filled laser tube rotates with the source. The operation of a ring laser gyro is likewise inconsistent with light being dragged by the gases within the laser tube.
  7. Assuming a dragging coefficient of 1, only the open air version of the Sagnac interferometer would work. Variants of the Sagnac interferometer where the transmitting medium rotates along with the source would not work.
  8. In other words, you have shot yourself in the foot by demonstrating that, assuming a dragging coefficient of 1, fibre optic gyros and ring laser gyros should essentially operate as if emission theory were true, i.e. they shouldn't be able to work at all.
Stigmatella aurantiaca (talk) 03:17, 24 February 2013 (UTC)

General comment This discussion is getting to be very tedious. You barely know your subject and constantly contradict yourself. If you want to expound on your private theory, I suggest that you either start a blog, or sign onto one of the physics forums that host interminable discussions about relativity by others like yourself. I suggest http://www.physicsforums.com/ or https://groups.google.com/forum/?fromgroups#!forum/sci.physics Stigmatella aurantiaca (talk) 03:48, 24 February 2013 (UTC)

If Siwei Pi Luo has at least a few reliable wp:secondary sources for what he proposes to add to the article, then the other contributors can simply decide whether the addition would be worth taking on board. Up to now, the above discussion was entirely about the subject, so it doesn't belong here per wp:TPG, and it clearly never should have escalated beyond Siwei's first reply.
Time to close and {{collapsetop|Off-topic discussion about subject}} ... {{collapsebottom}}? - DVdm (talk) 05:50, 24 February 2013 (UTC)
Thank you. I intended to archive this entire conversation and any future attempts by Siwei Pi Luo to renew the conversation as an off-topic discussion, but collapsing would also work. As a courtesy, we should wait for SPL to acknowledge that that is what we are doing. Stigmatella aurantiaca (talk) 08:16, 24 February 2013 (UTC)

Thanks for asking. Well, no problem for archiving it as an off-topic discussion.Siwei Pi Luo (talk) 19:18, 24 February 2013 (UTC)

 Ok, section partly collapsed. Cheers - DVdm (talk) 21:30, 24 February 2013 (UTC)
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