Text: For those of us who have forgotten the details, the infamous MMX allegedly showed us that the assumption that one could use the aether frame as a preferred frame of reference in which to measure such things as motion, is invalid. This told us more about the physical qualities of matter and electromagnetic energy, than about proof of the presence, of lack thereof, of an aether. It clearly demonstrated our conceived notions about matter (at that time) and its interactions with the aether were incorrect. But why is this one held in such high esteem as to warrant a discussion that makes no mention of the related experiments and their important contributions to the subject at hand. For example in the Michelson-Morley Experiment(MMX) A light beam is split into two perpendicular component paths, A and B which are of equal length. Path A is in the direction of earth's motion and path B is at right angles to A. It was expected that, due to earth's motion, the time to travel path A would be less than the time to travel path B, and therefore, upon reconverging the light beams the frequencies would be out of phase and would of necessity exhibit an interference pattern. No such interference was noted. The Kennedy-Thordike experiment is a variation on the MMX. A light beam is split into two perpendicular component paths, A and B. Paths A and B are of different lengths. Again, no such interference was noted, ruling out length contraction alone as being an explanation for the null results of the MMX. In the Trouton-Noble experiment a parallel plate capacitor was suspended from a single line, thus allowing the plate to rotate freely around the line. It was expected that the translational motion of the earth would result in a magnetic torque force on the charges resulting in the alignment of the plates parallel to the motion of the earth. No such torque force was discerned. In the Sagnac experiment a light beam is split into two perpendicular component paths, A and B. Path A travels through a glass disk from south to east at 45 degrees, from east to north at 135 degrees, from north to west at 225 degrees, and from west back to south at 315 degrees. Path B travels through the disk in exactly the opposite fashion. The beams are then reconverged and an interference pattern is determined. The glass disk is then rotated on its axis. It is expected that a fringe proportional to both the angular rotation and the area enclosed by the light path would result. The results of this experiment were in complete accord with expectations and completely consistent with an aether medium. Michelson-Gale is a variation of Sagnac's experiment described above, except that this variant used the earth's rotational motion. The results measured were again consistent with expectations and an aether medium. In the Thirring-Lenze experiment a balanced, freely rotating ring made from a highly dense material (such as tungsten) is centered around a compass type, inertial needle. The ring does not touch the needle. With this system in a vacuum, the ring is rotated at a high rate of speed. Since the ring is balanced and in no way touches the needle there should be no unbalanced forces acting on or through the needle and the needle would not be expected to move. However, if a physical medium pervades space, the rotation of the ring will result in a vortex forming at the center of rotation (this is my favorite part, it gives me goose bumps when I think of it). Since the needle exists in this vortex the needle will experience rotational drag and assume the rotational speed of the ring. This was a result predicted by general relativity (dragging the inertial frame) and identified in1915. The Fizeau experiment passes a beam perpendicularly through a flowing water stream. Differences in the index of refraction were measured relative to stationary water. The resulting measurements were fully consistent with both relativity and the aether concept. Special relativity doesn't need to invoke a physical medium to describe the processes. Thus, as Einstein stated, an aether isn't necessary for the formal definition of SR, as formulated. H. A. Lorentz formulated an aether based version of special relativity, known as Lorentz Ether Theory [LET] which is mathematically equivalent to classical SR in all known predictions and observations.

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