Update 6/NOV/2017 Gravity, AS ETHER, replaced with electromagNetic field, AS ETHER
Cut and paste: weinsteinsletter.weebly.com/aether.html
The Impossible Experiment An Impossible Experiment? The topics are the experiments of Michelson. Most usually Michelson was teamed with Morley, so I will use the abbreviation M&M to refer to Michelson's experiments. Sometimes another person whose name starts with M (of course) was paired with Michelson; so the abbreviation still holds. While the experiments of M&M ruled out many conceptions for light flow, it never really differentiated between Einstein's Special Relativity (ESR) and the Aether. To be more precise, I mean not just any concept of an aether but the totally entrained aether (TEA). Mostly Aether was considered the wind of the Universe. Some thought that the Aether was partially entrained – that is, partially captured by the Earth. However, just about nobody considered that the Aether could be totally entrained – that is, be a property of Earth. Total entrained aether (TEA) did not seem reasonable because light traversed the Universe. I am going to take the position that on Earth the Aether is totally entrained (we will be working with the concept of TEA). You may ask, how does the light get from some star to the Earth? My answer is: That is for the advanced class (next semester); in this class we stick to light on the Earth.
OK, so we are going to examine TEA and ESR, but mostly TEA, because you all know ESR.
First, we are going to examine the plain M&M instrument for comparing the speed of lights sent at right angles to one another. Since you know ESR, I would think that you maybe be familiar with the idea that a constant speeded, e.g., swimmer will swim across a river and back faster than the swimmer will be able to swim down a river and back (same distance). That fact, of course, assumes that the river is flowing (not at zero speed but at a speed less than the swimmer swims). As you may remember, from studying ESR, M&M found the speed of the two beams sent at right angles the same. Twice crossing the river of aether went as the same speed as going with and against the aether. That doesn't happen, unless the speed of the aether is zero. Because M&M twisted their apparatus around to examine all different angles at all different times of the day and year, it is quite unlikely that they somehow missed the moving aether. Surely the aether was still. And because nobody had use for a non-moving aether (relative to an Earth that was moving), surely they thought that the aether did not exist. Their reasoning, of course, did not consider a TEA.
Step one. What they didn't do, however, was to show that the M&M instrument could, in fact, detect a difference in speed. I always like to show that the apparatus works the way we think it works. So that's the first thing we have to do – demonstrate that the M&M apparatus can detect a difference in speed. Now that may be a waste of time, because when those who reported “no difference” in the speed of the two beams, they really meant to report that they wasn't a sufficient difference to account for the speed of the Earth around the Sun. This is what they missed. If you are looking for a horse to run 30 MPH, and you detect 3 MPH, then you might say the horse wasn't moving. But truly, the horse was walking and not running. Same with M&M. They should have (with my 20/20 hindsight) looked for other explanations (other than unexplained error) for the difference found in speed. We'll get back to this error later *.
Being able to show that you can detect a difference in speed, however, is not so easy. You have to zero the instrument. That means that whatever differences you get when you set up the instrument are set to zero. This is because the ability to set up the apparatus to measure a fraction of a millimeter doesn't exist. You have to set it up claiming no effect. So if there is some large difference that occurs because of an effect, you have to nullify the effect, and hope that a new version of an effect can be detected. Further, if the new version of the effect is small, then you are inclined to pass over the small effect (claiming it was some sort of an error). It's not easy being an experimenter.
Digression. Some optics firm was trying to tune the curvature of a mirror. They started with gross measurements and proceeded to use finer techniques. Finally, they “jumped” to the M&M interference procedure. I say jumped, because there was no step that could lead into the use of that M&M procedure. The M&M procedure was ultra fine. The last procedure for tuning before they jumped was very good but not even fine. Therefore, there could be a gap in tuning, and in fact there was a gap! They were off several sets of interference patterns – object-oriented progression suicide (oops). This is why you have to zero the M&M apparatus, and then look for an induced change after it was “calibrated.” Of course, this instructive error occurred decades after M&M's activities.
Step two. Basically, you want to zero the M&M instrument when you expect the effect to be small, and then hope to see an effect when the effect is expected to be large – more on this latter **. OK, for calibration, all we have to do is zero the device when we set it up. Then we add a sliver of glass (or plastic, anything with a refractive index greater than 1) into the single beam before it is split. Question 1: Does this change the finding of no difference? If it does, we have a problem. For the fun of it, add the glass somewhere else, such as after the dual beams are recombined. Question 2: Does this change the finding of no difference? If it does, we have a problem. Now we preform the crucial experiment for seeing whether we can detect a real difference. We insert the glass into one arm (one beam only) of the instrument. Question 3: Does this affect the “no difference”? If it does not, then we have a problem: we cannot use the M&M instrument for our purposes. Let's assume it does make a difference! Then we know that the M&M instrument works; that is the calibration.
OK, how do we detect TEA?
Version 1: We use the presumed electromagnetic (EM) field around a solid to change the TEA. Maybe we should tip the scales by using an excessive EM field. Use a rubber stick. Rub fur on the rubber. The rubber now has extra electrons on it. Place the rubber very close (near) one of the split beams. One beam travels up past the rubber and down past the rubber. The other beam is as it was. Question 4: Does the interference pattern change with nearby charged rubber? Yes, we found the TEA. No, then maybe we can increase the presumed interaction.
Version 2: Use a Van De-graf generator or a similar high voltage generator to collect electrons, and, thus, produce an electric field. Put the new and stronger field near a bream. Q5 is a repeat of Q4: Does a stationary electric field affect light?
From Faraday, we hear a strong magnetic field can change the phase of coherent light. Maybe that's all we've done: show that an electric field can affect a bream of light? Maybe that's all we have to do?
Version 3: Set up the M&M experiment in a near vacuum, and see whether the light can (still?) be affected by an electric field?
So what's the TEA; is it the electric field?
If we have a movie camera (or equivalent) we can observe the interference patterns as we alter the neighborhood of a single path of light. Does the light travel faster or slower within the greater electric field?
*: Can the speed of light be manipulated by means of an electric field (or electromagnetic field)? Can light really travel as light (fixed in speed) without being in an electric field? If we have the electric field moving, can we speed or slow the light? Is light's speed relative to the (local) electric field? **: Zeroing the M&M instrument hides the effect of the electromagnetic field on light. So we have to induce various electromagnetic fields and see what damage in done to ESR.
