(EBTX updated version 4/5/2006)
Why Michelson-Morley failed
The original Michelson-Morley experiment was done on a slab of concrete floating in a bath of mercury. The idea was to keep it perfectly still for one measurement then gently rotate it to another angle (90o turned from the first reading) for a second reading, so as to facilitate changes in interference fringes being seen which could be ascribed to the direction of travel through the "luminiferous ether" (the light-carrying medium). No effect was seen, so the ether was dropped from the Standard Model.
I have given the cause of this null result as due to the Lorentz contraction (a real phenomenon) which should have been anticipated by the experimenters prior to doing the experiment. They should have surmised that the slab on which the experiment rested would have to "shrink" (relativistically) in the direction of motion because the molecules the slab was made of ... were also "in the wind" ... and ... since the interaction holding molecules together also is transmitted through the ether (mediated by the electro-magnetic interaction) ... it should have been expected to contract as well thus nullifying any anticipated results.
Why isn't this obvious even in hindsight?
Rotating the slab dynamically
My solution to this logical problem is to do the experiment while the slab (or its equivalent) is rotating. The purpose of this is to change the shape of the slab which must occur ... IF ... the ether does, in fact, exist.
I have given the reason for this change of shape here. And here is the pic from that page.
As you can see, a sphere rotating in space and also having translational motion through the hypothetical ether, should be somewhat misshapen due to the variation of its "absolute velocity" through the absolute medium. Imagine then that the slab of concrete is rotating at some reasonable speed (as much as it will tolerate). Then, when the slab is not rotating (relative to the backdrop of stars), it will not be misshapen ... and it will be perfectly circular in our reference frame while at rest in that frame (non-rotating).
If we now do the Michelson-Morley experiment while the slab is rapidly rotating its shape will change asymmetrically as shown in the above figure ... and ... the lengths of travel for the two legs of the experiment will not be the same as when at rest (non-rotating). Thus, if the ether (absolute reference frame) does in fact exist ... it MUST be detectable by these means. IF it cannot be detected ... then ... and only then ... is the ether to be discarded from our theoretical models.
Mechanically - how to do it
We need to put the two legs of the experiment off center on the slab so that one leg is parallel to the Z axis in the above figure and entirely on the most contracted side ... and ... the other leg parallel to the X axis which is unchanging in the experiment at distances not to far from center. Here is the slab as seen from above and from the side.
I can't make a really good representation of the mirror arrangement since they get in each others way however I try to draw them. But you understand what's going on here. A laser from above is shot down the axis and split by half silvered mirrors and goes on two different paths ... then back up the axis to a detector where interference fringes can be displayed. All the while, the slab is rotating as fast as possible to mis-shape the slab via relativistic contraction.
Also, another important part would be a strobe effect so that we would see only those interference fringes that exist when the slab is in a selected position (computer controlled DLP processor would be ideally suited to this job). By checking the differences at different positions, one could tell which direction produced the biggest differences ... and ... that would be the direction we are headed in. Presumably, that would be in the same direction we are headed in through the cosmic microwave background radiation at about 379 kilometers per second (I think it was) in the general direction of the constellation Leo.
Here's a good link to CMBR direction analysis
The following pic shows the schematic slab and four directions after one revolution. It's fairly self-explanatory to anyone who doesn't yet "get it".
I should make this clearer. In the above figure, in the laboratory frame of reference, all situations (1,2,3,4) should give the same result if special relativity is correct. If there is a detectable absolute reference frame, the situations at #2 and #4 are different. In both 2 and 4, the length of path A is the same but the length of path 2B is shorter than 4B because 2B is moving faster relative to the absolute frame of reference. Hence the time required for light to be reflected back and forth several times between the end reflectors along these paths (during the short interval when the table is moving near these positions) is necessarily different. There should be a measurable shift in the interference fringes of 2 and 4 because the situations are different ... with respect to the absolute reference frame ... by way of their dynamical differences.
If all pathways are initially measured to be of equal length (on the table, at rest relative to the laboratory) ... when put into motion by the table's rotation, the path with the greater velocity (relative to the absolute reference frame) will be shorter but will also require a longer time for light to reflect back and forth along that path due to standard relativistic considerations. Conversely, the formerly identical path (now on the other side of the rotating table) will have a greater length and a lesser time of travel for its reflected light. When these two are compared ... simultaneously ... the resulting interference fringes will change through the cycle of the table's rotation.
It occurs to me that an even simpler arrangement would be this. Just have two parallel pathways ... offset from the center of rotation ... then the fringe measurements would be identical in 2 and 4 but different from 1 and 3 and this would serve to indicate a preferred direction in space. For, once again, if special relativity is correct, there could be no discernible difference between any position (1,2,3 or 4) regardless of whether the table is rotating or not.
This would be a difficult experiment to tackle ... much more difficult than the original ... but it will give a logically straightforward result and those results are probably predictable quantitatively because one could calculate the distortion of the slab caused by rotation using standard relativistic equations. I might add here ... this must work ... IF ... the ether exists. If not ... well, that's that.
PS: - I reserve the right to retract all the above web page ... IF ... I've made some conceptual error (which should be the case ... unless Albert has made the error - fat chance, eh? ;o)
Happy Easter!! The above experiment won't work (wouldn't ya' know it?).
Here's why ...
Here at A1 and B1 ... light enters the two sides of the experiment symmetrically. But at A2 and B2 the slab has rotated by a certain amount dependent on the duration of travel time through that side. Now, that duration is more on the A side because that side is now Lorentz contracted and time slowed more than the other. But when the signal is sent back to meet with the other signal for the interference measurement, it travels back ... downwind ... from point A2 which takes less time. Vice versa for the B side. Because the return path is from B is upwind it takes longer and that cancels out the shorter duration on the B side experiment. Because the return paths are dependent on the duration of the experimental paths on both sides ... and ... are necessarily offsetting ... we can conclude that this setup will yield a null result just like the stationary experiments. We can see that geometry is conspiring to support the standard Michelson-Morley results and this is a sure sign in physics that we are just spinning our wheels.
End of story. My revised experiment will fail and needn't be done. Well, that was expected. I've been down this road before and it never has gone anywhere but to the expected. Se la guerre.