Most scientists accepted relativity joyfully. By abandoning physical reasoning, and accepting pure mathematical formalism, it gave them a plausible excuse to ignore all the evidence that the earth is stationary. Part of their acceptance required rejecting the existence of the aether. But a French scientist called Sagnac seemed unconvinced. No one had ever proved that the earth was actually moving, and Relativity was based on the assumption that it must be moving. In fact Relativity is largely an ad hoc to explain away the observations that show the earth to be stationary at the centre of the universe (Einstein's denial notwithstanding!).
Sagnac built a turn-table with mirrors on it arranged in such a way that a beam of light was split into two beams, one was reflected from mirror to mirror anticlockwise around the turntable, the other was reflected around clockwise. After a complete circuit the beams were recombined in a camera to give interference fringes. Looking at it in a very simplified way, when the turntable was set spinning there was known to be movement, the beam going round with the turn table's rotation would be chasing the camera (which is moving away at speed v) with a relative speed of c-v, whereas the beam going against the rotation would approach the camera "head on" with a relative speed of c +v. If the basic assumptions of Relativity were correct, with c + v = c-v, and no aether, then there should be no fringe shift.
But there was a fringe shift. A basic assumption of Relativity was apparently wrong. More explanations were needed to keep Relativity and the motion of the earth alive. But the excuses of the relativists were tested, experimentally and theoretically, and found to be invalid. Eventually the famous physicist Herbert Ives pointed out that the only way to carry on believing in Relativity was to "avoid looking at the evidence." Arguments are still being put forward to explain away Sagnac's experiment. Interestingly enough there are a number of explanations of such problems for Einstein's "Special Theory of Relativity" (STR) which appeal to his "General Theory of Relativity" (GTR).
Now STR cannot have an aether and must have a constant velocity of light. On the other hand GTR is, as Einstein put it "unthinkable without the aether" and cannot tolerate a constant velocity of light. The two theories are mutually exclusive. At least one must be wrong. To solve difficulties for one by calling in the other is clearly invalid.
Michelson, together with a new collaborator called Gale, thought of a way to test whether the aether exists or not. They built a tunnel of pipe sections at Chicago. The tunnel was in the form of a large rectangle. They reasoned that if there were an aether, then the rotation of the earth from west to east through it should cause a beam of light travelling clockwise round the tunnel to take slightly less time to get round than a beam travelling anticlockwise. If there were no aether then both beams would take the same time. the earth's rotation. The same result would be observed if the earth were rotating and the aether were standing still, or if the earth were standing still with the universe, including the aether rotating around it,
or if the earth were partially rotating and the aether were partially rotating.They measured a difference. Existence of aether established. The author of the words above is
Marshal Hall, if i remember well, he is a geocentrist, however he made the same mistake as JackBlack did (pay attention to the words in red)...
Now, this is going to be interesting (how i responded to one of infamous JackBlack's stupid lies) :
---The only acceptable conclusion that can be drawn from these two experiments, Michelson–Morley, on the one hand, and Michelson–Gale, on the other hand, is that the hypothesis of the existence of a medium of propagation for light is not tenable, unless we accept geocentric implications from the combined effect of both experiments (MM and MGP). In the classical context, it is clear that the Sagnac effect cannot at all be explained, unless we admit that the earth is at rest while the whole universe rotates around the stationary earth.
Completely wrong.
Firstly, it wouldn't matter if Earth was rotating with the aether at rest, Earth was at rest with the aether rotating around Earth, or both rotating around the axis of Earth. All three would produce the same result.
But more importantly, that ignores stellar aberration, which makes sense in the context of Earth having a speed of roughly 30 km/s.
The detection of stellar aberration combined with the MM experiment refutes the aether model entirely.
1. Let's consider hypotesis No 1 : "If Earth was rotating with the aether at rest" :
If we assumed that the earth is rotating with the aether at rest then we would have to deal with totally different kind of problem :
Instead of being unable to detect earth's orbital motion (Joos' upper limit = 1,54 km/s), and being able (by Michelson, Gale and Pearson) to establish (and confirm (by others) with different methods (see above)) an exact daily rotational velocity of an aether (even exactly matching expected speeds for a given latitudes), in such hypothetical situation (HC scenario) we would have to face quite an opposite difficulty : since the orbital velocity of the earth is almost 100 times greater than the earth's alleged rotational velocity at 40° N latitude, MGP kind of an experiments would yield much higher results (than expected), and MM kind of an experiments would regularly register exactly 108 000 km of earth's orbital velocity.
2. Let's consider hypotesis No 2 : "Earth was at rest with the aether rotating around Earth" :
This is perfectly in accordance with reality : no orbital motion of the earth, no rotational motion of the earth, and an aether rotates around the motionless earth once per day.
3. Let's consider hypotesis No 3 : "or both rotating around the axis of Earth" :
This is utter nonsense, and here is why :
A) Aether rotates in the same direction of earths rotation twice faster than the earth : This would be the only way how someone could
measure 363 m/s for the rotational speed of aether (around rotational earth) at 40°N.
PROBLEM : Wrong direction of aether's rotation. (atmospheric charges wouldn't flow faster westward, but eastward)
B) Aether rotates with the same speed of the earth in the same direction of earth's rotation.
PROBLEM : Atmospheric charges wouldn't flow faster neither westward nor eastward.
C) Aether rotates in an opposite direction of earth's rotation (at any speed).
PROBLEM : We would measure rotational speed of a rotating aether which would exceed earth's rotational speed.
ON TOP OF THAT : All three solutions (A,B,C) would be of a minor significance (if any significance at all) since we wouldn't be able to measure rotational speed of an aether around the rotating earth since the speed of aether flow due to orbital motion of the earth would be much (100 times) higher than the speed of an aether due to rotational motion of the earth (see No 1, above).
ACCOMPANYING POST :
https://www.theflatearthsociety.org/forum/index.php?topic=78424.msg2126528#msg2126528