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Dimensional analysis:
You should start with dimensional analysis before even try to talk about physics. This is the most basics you always have to check in formulas. This has not even to do with physics yet. And you think you can talk about relativity to physicists and engineers. You don't become a mathematician or physicist by using google.
And as long as v is less than or equal to c we get a positive number inside the square root. If v is greater than c we get a negative number in the square root, which has no real solution.
If v = c we get sqrt(0) = 0 which is a problem if this term is in the denominator like in the formula for time dilation.
That's how math tells the speed of light (c) must be a limit.
You should start with dimensional analysis before even try to talk about physics. This is the most basics you always have to check in formulas. This has not even to do with physics yet. And you think you can talk about relativity to physicists and engineers. You don't become a mathematician or physicist by using google.
And as long as v is less than or equal to c we get a positive number inside the square root. If v is greater than c we get a negative number in the square root, which has no real solution.
If v = c we get sqrt(0) = 0 which is a problem if this term is in the denominator like in the formula for time dilation.
That's how math tells the speed of light (c) must be a limit.
Where K and K' are 2 different inertial reference frames moving with respect to each other.
Witsit fails in every possible aspect. He has no clue what he reading.
Witsit fails in every possible aspect. He has no clue what he reading.

where K and K' are 2 different inertial reference frames moving with respect to each other.
An inertial system is a frame of reference in which the law of inertia - Newton's first law - holds. In such a system which also may be described as an unaccelerated system, a body that is acted on by zero net external force which moves with a constant velocity.
So positions and velocities are always relative with respect to a certain external reference. A reference frame can't have a position or velocity itself, because there is no absolute position or velocity. And it turned out there is no such thing as an aether, which would be an absolute reference, that could be used to measure speed without any reference to an external reference.
An inertial system is a frame of reference in which the law of inertia - Newton's first law - holds. In such a system which also may be described as an unaccelerated system, a body that is acted on by zero net external force which moves with a constant velocity.
So positions and velocities are always relative with respect to a certain external reference. A reference frame can't have a position or velocity itself, because there is no absolute position or velocity. And it turned out there is no such thing as an aether, which would be an absolute reference, that could be used to measure speed without any reference to an external reference.
Principle of Relativity - The Principle of Relativity is an Audacious Thing. It is a law that governs the laws of physics.
If you can imagine that, someone conceiving of a law that governs the laws of physics.
Each law of nature must be the same in every reference frame.
Principle of Relativity not new and came from Galileo
Newtons laws of motion are invariant when you go from one Inertial frame of reference to another under Galilean transformations. Simply put the laws of physics are the same in all inertial reference frames.
Galilean transformations are simple equations that connect the measurements of space and time, between two different observers in two different frames of reference.
If you can imagine that, someone conceiving of a law that governs the laws of physics.
Each law of nature must be the same in every reference frame.
Principle of Relativity not new and came from Galileo
Newtons laws of motion are invariant when you go from one Inertial frame of reference to another under Galilean transformations. Simply put the laws of physics are the same in all inertial reference frames.
Galilean transformations are simple equations that connect the measurements of space and time, between two different observers in two different frames of reference.
POSTULATES OF SPECIAL RELATIVITY
1. Principle of Relativity – All the laws of physics are the same in all
inertial reference frames.
2. The speed of light in a vacuum is the same (3.0 x108 m/s) in all
inertial reference frames regardless of the motion of the observer or source.
Consequences of Special Relativity
1. Principle of Relativity – All the laws of physics are the same in all
inertial reference frames.
2. The speed of light in a vacuum is the same (3.0 x108 m/s) in all
inertial reference frames regardless of the motion of the observer or source.
Consequences of Special Relativity
Here you are running down Washington blvd in your high speed sports car. You have a reference frame inside there and inside this car, and inside there you do an experiment to study the laws of Nature. For example you study the Lorenz force law.
I stand outside you on the street and do the identical experiment. Relativity says we should get exactly the same answer. We have to see these force laws from electromagnetism must be identically the same for you at high speeds in your car and for me out in the street.
[note: it is not quite right because there is gravity but we can do a thought experiment out in interstellar space.
Really remarkable consequences from this principle.
I stand outside you on the street and do the identical experiment. Relativity says we should get exactly the same answer. We have to see these force laws from electromagnetism must be identically the same for you at high speeds in your car and for me out in the street.
[note: it is not quite right because there is gravity but we can do a thought experiment out in interstellar space.
Really remarkable consequences from this principle.

Michelson-Morley’s 1887 experiment falsified the Aether hypothesis. Flat earthers reject this conclusion and claim the experiment “proved the earth is stationary”.
The original assumption that was being tested was that just like sound waves through air, the observed speed of light through an aether would depend linearly on how fast you're moving through the aether (Galilean Relativity), and that Earth was moving relative to any potential aether. The hypothesis that they came up with from these assumptions was that light would take longer to travel across the MM apparatus in one direction compared to another. Specifically, they figured that the direction perpendicular to the flow of aether would mean light would have to take a diagonal (therefore longer) path through the aether while the parallel direction would not. This would show up as a shift in fringe pattern as the apparatus rotated as the trough and crests of the light interfered.
Fringe Shift difference between 90 degree change.
That way arms do not have to be so precise.
https://www.quora.com/How-did-Michelson-and-Morley-measure-the-speed-of-light
The original assumption that was being tested was that just like sound waves through air, the observed speed of light through an aether would depend linearly on how fast you're moving through the aether (Galilean Relativity), and that Earth was moving relative to any potential aether. The hypothesis that they came up with from these assumptions was that light would take longer to travel across the MM apparatus in one direction compared to another. Specifically, they figured that the direction perpendicular to the flow of aether would mean light would have to take a diagonal (therefore longer) path through the aether while the parallel direction would not. This would show up as a shift in fringe pattern as the apparatus rotated as the trough and crests of the light interfered.
Fringe Shift difference between 90 degree change.
That way arms do not have to be so precise.
https://www.quora.com/How-did-Michelson-and-Morley-measure-the-speed-of-light
Original and Rotated Setup
t - t' = shift in fringes interference patterns (Light and dark bands)
v^2/c^3(L1 + l2)
If t and t' not same
Theoretically fringe shift can be calculated.
Should have been 37 percent shift.
This is a failed experiment because it started with the assumption that you were going to see an interference pattern.
Should have gotten an interference pattern shift.
It failed to prove the existence of Aether.
And showed we cannot treat light in the same way we treat other waves.
t - t' = shift in fringes interference patterns (Light and dark bands)
v^2/c^3(L1 + l2)
If t and t' not same
Theoretically fringe shift can be calculated.
Should have been 37 percent shift.
This is a failed experiment because it started with the assumption that you were going to see an interference pattern.
Should have gotten an interference pattern shift.
It failed to prove the existence of Aether.
And showed we cannot treat light in the same way we treat other waves.

Special Relativity gets rid of the aether. So no preferred reference frame exists, like we would have, if the aether would exist. That means there is no such thing as intrinsic or absolute position and motion (and there is no experiment that can measure it). Position and motion are not properties of a reference frame itself and hence there is no physical experiment that can measure and assign motion to a certain inertial reference frame. That's the cause why MM gives a null result. Position and motion are always relative to some other reference frame. To measure motion you have to reference another reference frame to which you measure the change in position. No specific reference frame is more special than any other. That's the principle of relativity, one of the postulates of SR.
In a car, your speedometer measures the rotation of the axle -- it literally counts how many times it goes around per unit time and guesses a speed based on that given the standard tire size for that vehicle. Change your tire size and it will read out incorrectly.
Note: Michelson interferometers are, by design, insensitive to rotation. If you want to detect rotation, you need a Sagnac interferometer like a ring laser gyroscope OR a Foucault Pendulum OR a mechanical gyro.
What is invariant for both reference frames is the spacetime interval.
In a car, your speedometer measures the rotation of the axle -- it literally counts how many times it goes around per unit time and guesses a speed based on that given the standard tire size for that vehicle. Change your tire size and it will read out incorrectly.
Note: Michelson interferometers are, by design, insensitive to rotation. If you want to detect rotation, you need a Sagnac interferometer like a ring laser gyroscope OR a Foucault Pendulum OR a mechanical gyro.
What is invariant for both reference frames is the spacetime interval.
The Earth's Orbit Cannot Be Detected with MM Apparatus!
Relativity and Earth's Orbit around the Sun
Witsit insists the Michelson Morley experiment is called the greatest failed experiment because it did not detect Earth's orbital speed of 30 km/s! Wrong!
Witsits argument, that the orbital velocity can not be measured on earth (no reference to the outside) with any experiment, is only true for MM-like optical experiments. So if you are not allowed to reference the sun or stars, you can not get a position or velocity or any orbital parameters of the earth at all. That follows from the principle of relativity (physics is the same in all inertial reference frames) alone and has nothing to do with special relativity, aether, length contraction and time dilation, as Witsit thinks.
So positions and velocities are always relative with respect to a certain external reference. A reference frame can't have a position or velocity itself, because there is no absolute position or velocity. And it turned out there is no such thing as an aether, which would be an absolute reference, that could be used to measure speed without any reference to an external reference.
This is what Einstein means when he says there is no physical experiment that can detect uniform motion of the reference frame itself. If such a thing as aether would exist, then we could measure the velocity with respect to this aether with a physical experiment like the MM experiment without any reference to an external reference frame.
Not even Michelson & Morley ever doubted Earth orbited the Sun as is evidenced in their papers.
Witsits argument, that the orbital velocity can not be measured on earth (no reference to the outside) with any experiment, is only true for MM-like optical experiments. So if you are not allowed to reference the sun or stars, you can not get a position or velocity or any orbital parameters of the earth at all. That follows from the principle of relativity (physics is the same in all inertial reference frames) alone and has nothing to do with special relativity, aether, length contraction and time dilation, as Witsit thinks.
So positions and velocities are always relative with respect to a certain external reference. A reference frame can't have a position or velocity itself, because there is no absolute position or velocity. And it turned out there is no such thing as an aether, which would be an absolute reference, that could be used to measure speed without any reference to an external reference.
This is what Einstein means when he says there is no physical experiment that can detect uniform motion of the reference frame itself. If such a thing as aether would exist, then we could measure the velocity with respect to this aether with a physical experiment like the MM experiment without any reference to an external reference frame.
Not even Michelson & Morley ever doubted Earth orbited the Sun as is evidenced in their papers.
That is we have a number of observations that confirm the earth orbits the sun such as:
Stellar Parallax, Stellar aberration, Redshift, Retrograde motion of planets and observations of orbits (like moons of Jupiter), Annual Doppler shifts
Additionally, the laws of gravitation, Kepler's laws, measurement of AU and the mass of the Sun and Earth all fit together only in the heliocentric setup.
Tiny parallax angles are difficult to measure, but today, ESA's Gaia spacecraft has measured the parallax of more than 1 billion stars in the Milky Way with great precision!
Now according to Witsit the Stars and Aether are moving while the earth is stationary and somehow this can explain the complex movements of the stars and planets. But such a relative motion between the earth and stars can only account for the diurnal motion of stars from east to west. A stationary Earth cannot explain parallax and aberration along with the aforementioned examples. He uses Tycho Brahe's geocentric model to explain some of these observations, but fails miserably to provide any mechanism.
Stellar Parallax, Stellar aberration, Redshift, Retrograde motion of planets and observations of orbits (like moons of Jupiter), Annual Doppler shifts
Additionally, the laws of gravitation, Kepler's laws, measurement of AU and the mass of the Sun and Earth all fit together only in the heliocentric setup.
Tiny parallax angles are difficult to measure, but today, ESA's Gaia spacecraft has measured the parallax of more than 1 billion stars in the Milky Way with great precision!
Now according to Witsit the Stars and Aether are moving while the earth is stationary and somehow this can explain the complex movements of the stars and planets. But such a relative motion between the earth and stars can only account for the diurnal motion of stars from east to west. A stationary Earth cannot explain parallax and aberration along with the aforementioned examples. He uses Tycho Brahe's geocentric model to explain some of these observations, but fails miserably to provide any mechanism.
Length Contraction
In your reference frame, where you are stationary, there is no length contraction and no time dilation. You see length contraction and time dilation only in reference frames that are moving with respect to you (the direction does not matter). You never have length contraction and time dilation in an inertial reference frame.
Witsit could be right if aether were existing. Because with the aether it is predicted that light in the direction of motion will take longer in the MM experiment than perpendicular to it. This is not what was measured. So to keep the aether alive you have to invent length contraction in the direction of motion, so that we have equal times.
But we now know of course that there is no such aether. So there is no length contraction necessary. SR explains this perfectly. It's all caused by the invariance of the speed of light and symmetries of nature, and the postulates of SR.
A good example where SR shows up is the muon decay. Muons are created by cosmic rays that collide with the upper atmosphere. The muons travel near the speed of light towards the surface of the earth. The mean decay time is very short, so without SR muons could not reach the surface. They would decay much farther up. But they DO reach the surface. That means, as seen from our reference frame on earth the time of the very fast muon slows down, so they live long enough to reach the surface. From the perspective of the muon time does not slow down. But the distance from the upper atmosphere to the surface contracts from the perspective of the muon, so it can reach it during his natural decay time.
So fact is that the muons reach the surface. From our perspective it's because the time of the muon slows down. From the perspective of the muon the distance contracts. What is invariant for both reference frames is the spacetime interval.
d tau^2 = (c dt)^2 - dx^2 - dy^2 - dz^2 = (c dt')^2 - dx'^2 - dy'^2 - dz'^2
Note: neither for you nor for the muon does the local time slow down nor the length contract. This are only effects seen in other reference frames.
In your reference frame, where you are stationary, there is no length contraction and no time dilation. You see length contraction and time dilation only in reference frames that are moving with respect to you (the direction does not matter). You never have length contraction and time dilation in an inertial reference frame.
Witsit could be right if aether were existing. Because with the aether it is predicted that light in the direction of motion will take longer in the MM experiment than perpendicular to it. This is not what was measured. So to keep the aether alive you have to invent length contraction in the direction of motion, so that we have equal times.
But we now know of course that there is no such aether. So there is no length contraction necessary. SR explains this perfectly. It's all caused by the invariance of the speed of light and symmetries of nature, and the postulates of SR.
A good example where SR shows up is the muon decay. Muons are created by cosmic rays that collide with the upper atmosphere. The muons travel near the speed of light towards the surface of the earth. The mean decay time is very short, so without SR muons could not reach the surface. They would decay much farther up. But they DO reach the surface. That means, as seen from our reference frame on earth the time of the very fast muon slows down, so they live long enough to reach the surface. From the perspective of the muon time does not slow down. But the distance from the upper atmosphere to the surface contracts from the perspective of the muon, so it can reach it during his natural decay time.
So fact is that the muons reach the surface. From our perspective it's because the time of the muon slows down. From the perspective of the muon the distance contracts. What is invariant for both reference frames is the spacetime interval.
d tau^2 = (c dt)^2 - dx^2 - dy^2 - dz^2 = (c dt')^2 - dx'^2 - dy'^2 - dz'^2
Note: neither for you nor for the muon does the local time slow down nor the length contract. This are only effects seen in other reference frames.
Is contraction/shortening a real physical phenomena according to SR?
Yes. But it does never happen for an observer in his own reference frame. The physics is the same in all inertial reference frames, no change in length or time. But from the perspective of another observers reference frame, moving relative to us, lengths in our reference frame appear contracted in the direction of motion and time dilated and vice versa. The apparent contradictions are an artifact of us regarding space and time as separate absolute entities, which they are not.
1 inch in frame A will physically measure shorter in frame B moving relative to it, and vice versa, 1 inch in frame B will measure shorter than an inch in frame A. Similarly, 1 second in frame A will last longer in frame B, and 1 second in frame B will last longer in frame A. These two effects conspire to keep the measured speed of light constant between both frames.
Yes. But it does never happen for an observer in his own reference frame. The physics is the same in all inertial reference frames, no change in length or time. But from the perspective of another observers reference frame, moving relative to us, lengths in our reference frame appear contracted in the direction of motion and time dilated and vice versa. The apparent contradictions are an artifact of us regarding space and time as separate absolute entities, which they are not.
1 inch in frame A will physically measure shorter in frame B moving relative to it, and vice versa, 1 inch in frame B will measure shorter than an inch in frame A. Similarly, 1 second in frame A will last longer in frame B, and 1 second in frame B will last longer in frame A. These two effects conspire to keep the measured speed of light constant between both frames.

So are this Length Contraction/Time Dilation effects only apparent?
No. This effects are real but can only be seen when one of the reference frames changes its motion, so it's not an inertial reference frame anymore, and the 2 observers meet again. If the observers meet again, then there is a real time difference between the 2 reference frames. In the the non-inertial reference frame there has less time elapsed with respect to the inertial reference frame. (A reference frame on a geodesics is by definition an inertial reference frame. You never have length contraction and time dilation in an inertial reference frame).
How is this possible? It's a consequence of 4 dimensional spacetime and the Lorentz transformation.
This can be explained by drawing Minkowski diagrams. When the non-inertial reference frame changes its inertial motion (doesn't matter how fast), its reference frame rotates in spacetime with respect to the inertial reference frame so that when they meet again, the elapsed times are not the same anymore. The rotation of the reference frame in 4D spacetime brakes the symmetry. This is confirmed in countless experiments and applications.
So length contraction and time dilation are real physical effects, but can only be observed if one reference frame is not inertial, but turns around or moves in a circle.
>Does the path of light shorten due to length contraction?
In the own reference frame and in the co-moving reference frame of the MM interferometer: NO.
No. This effects are real but can only be seen when one of the reference frames changes its motion, so it's not an inertial reference frame anymore, and the 2 observers meet again. If the observers meet again, then there is a real time difference between the 2 reference frames. In the the non-inertial reference frame there has less time elapsed with respect to the inertial reference frame. (A reference frame on a geodesics is by definition an inertial reference frame. You never have length contraction and time dilation in an inertial reference frame).
How is this possible? It's a consequence of 4 dimensional spacetime and the Lorentz transformation.
This can be explained by drawing Minkowski diagrams. When the non-inertial reference frame changes its inertial motion (doesn't matter how fast), its reference frame rotates in spacetime with respect to the inertial reference frame so that when they meet again, the elapsed times are not the same anymore. The rotation of the reference frame in 4D spacetime brakes the symmetry. This is confirmed in countless experiments and applications.
So length contraction and time dilation are real physical effects, but can only be observed if one reference frame is not inertial, but turns around or moves in a circle.
>Does the path of light shorten due to length contraction?
In the own reference frame and in the co-moving reference frame of the MM interferometer: NO.
Witsit has understood SR, you can ask him some of the following questions:
- Q: What does the "principles of relativity" mean (not to confuse with SR)?
- A: The equations describing the laws of physics have the same form in all admissible reference frames. They prescribe symmetries in natural laws.
- Q: What are the postulates of SR?
- A: Principle of relativity (homogeneity, isotropy, physics is the same in all reference frames) and there is an invariant speed and this speed is the absolute local limit for the propagation of causality
- Q: What is a four-vector?
- A: A spacetime vector like P = ( ct, x, y, z ), V = (c, vx, vy, vz)
- Q: What does invariance mean?
- A: Is the same regardless of frame of reference, e.g. the spacetime interval, the speed of light
- Q: What is the analog to a distance in 3D space in SR?
- A: The spacetime interval = the distance between 2 spacetime events. A spacetime event is a position 4-vector.
- Q: What's the spacetime interval for light?
- A: Always Zero; follows from the invariance of c
- Q: What is invariant under Lorentz transforms
- A: The spacetime interval, the speed of causality, e.g. the speed of light, the laws of physics
- Q: What's the difference between Galilean transformation and Lorentz transformation?
- A: Galilean: 3D space, c = infinte; Lorentz: 4D spacetime, c = finite
When Einstein refers to Ether, he's still referring to "ether" as a field, i.e. a quantity which has value over all space. In this instance, the value is the curvature of space itself. It becomes apparent in one of the other quotes you like to bring up.
Besides Michelson Morley there have been many experiments that have ruled out the Aether.
The
Aberration, Sagnac effect, Michelson-Gale all show that the ether isn't being dragged in the vicinity of the Earth. So then there must be a relative velocity between the ether and Earth, if ether exists.
Even Austin thinks that the ether is vortexing like a toroid. And he uses that alleged vortex to account for Bob's 15 degrees/h. But if that's the case, the MM expt., Kennedy-Thorndike & similar ones should all have detected the expected fringe shifts. But none did. This disagreement among a multitude of results is what kills the ether hypothesis.
The
Aberration, Sagnac effect, Michelson-Gale all show that the ether isn't being dragged in the vicinity of the Earth. So then there must be a relative velocity between the ether and Earth, if ether exists.
Even Austin thinks that the ether is vortexing like a toroid. And he uses that alleged vortex to account for Bob's 15 degrees/h. But if that's the case, the MM expt., Kennedy-Thorndike & similar ones should all have detected the expected fringe shifts. But none did. This disagreement among a multitude of results is what kills the ether hypothesis.
General Relativity - NLR Doesn't Work!!
The idea is that in flat space (i.e. SR), there can be an absolute time reference (universal "present"), and everyone's own time is just a different rate at which they perceive the flow of that absolute reference, and you can just do some transformation between the local reference frame and one where time flows at the absolute rate. The laws of physics don't change with that assumption.
But with curved space in GR, different regions will have time flow at different rates, if you try to apply the same concept, that the rate for each local time is just some factor of the absolute time, and there is no transformation you can do which can get you to some absolute reference frame, since there will always be some variation of the rate in the flow of time somewhere that doesn't match. The laws of physics do look different when trying to do so, and introduce forces that seem to come out of nowhere, which we perceive as the force of gravity.
The curvature in General Relativity includes not only space, but time as well. In curved spacetime, there is no possible way to define the passage of time and the length of distances as a ratio compared to some absolute frame, since it would change depending on the position of the observer, and for an other observer moving relative to the first, there would be a completely different set of ratios of time and length which have their own position dependence. They won't even be able to agree on their relative shapes of spacetime as no matter what, it would appear locally flat to them.
Trouton–Rankine experiment
The Trouton–Rankine experiment was an experiment designed to measure if the Lorentz–FitzGerald contraction of an object according to one frame (as defined by the luminiferous aether) produced a measurable effect in the rest frame of the object, so that the ether would act as a "preferred frame". The experiment was first performed by Frederick Thomas Trouton and Alexander Oliver Rankine in 1908.
The outcome of the experiment was negative, which is in agreement with the principle of relativity (and thus special relativity as well), according to which observers at rest in a certain inertial reference frame, cannot measure their own translational motion by instruments at rest in the same frame. Consequently, also length contraction cannot be measured by co-moving observers. See also Tests of special relativity.
The Trouton–Rankine experiment was an experiment designed to measure if the Lorentz–FitzGerald contraction of an object according to one frame (as defined by the luminiferous aether) produced a measurable effect in the rest frame of the object, so that the ether would act as a "preferred frame". The experiment was first performed by Frederick Thomas Trouton and Alexander Oliver Rankine in 1908.
The outcome of the experiment was negative, which is in agreement with the principle of relativity (and thus special relativity as well), according to which observers at rest in a certain inertial reference frame, cannot measure their own translational motion by instruments at rest in the same frame. Consequently, also length contraction cannot be measured by co-moving observers. See also Tests of special relativity.
Part 2: Sidereal Rotation - Machian Principle Stuff
But then this position contradicts this whole position with sidereal rotation of the Aether causing centrifugal and Coriolis effects to drag the pendulum around as you have said. So do ballistics curve or not in the vortexing Aether? Because if there are centrifugal and Coriolis effects that can drag a pendulum around, the answer must be yes.
I just don't see how you can have it both ways? This is not a gotcha Austin, it is simply trying to understand your position so I can respond more accurately,Part 1: Stationary
If I hear you correctly, you think that MM should have measured the orbit of the earth around the sun, and because it did not, that changed all of physics.
If he accepts the idea of frame dragging from a rotation shell around the Earth being the cause of the precession of the Foucault pendulum, then he must also accept the rest of General Relativity with the point that gravitational acceleration is not due to "disequilibrium of densities" or whatever he calls it, since in GR it's due to mass curving spacetime and objects in freefall following geodesics, and a flat Earth would not have the apparent acceleration perpendicular to a flat disk (if he tries to claim an infinite sized disk, then that precludes the possibility of an enveloping rotating shell).
But then this position contradicts this whole position with sidereal rotation of the Aether causing centrifugal and Coriolis effects to drag the pendulum around as you have said. So do ballistics curve or not in the vortexing Aether? Because if there are centrifugal and Coriolis effects that can drag a pendulum around, the answer must be yes.
I just don't see how you can have it both ways? This is not a gotcha Austin, it is simply trying to understand your position so I can respond more accurately,Part 1: Stationary
If I hear you correctly, you think that MM should have measured the orbit of the earth around the sun, and because it did not, that changed all of physics.
If he accepts the idea of frame dragging from a rotation shell around the Earth being the cause of the precession of the Foucault pendulum, then he must also accept the rest of General Relativity with the point that gravitational acceleration is not due to "disequilibrium of densities" or whatever he calls it, since in GR it's due to mass curving spacetime and objects in freefall following geodesics, and a flat Earth would not have the apparent acceleration perpendicular to a flat disk (if he tries to claim an infinite sized disk, then that precludes the possibility of an enveloping rotating shell).
But Mechanical Gyros CAN Pick Up the Earth's Rotation!
"I believe the Flat Earth community is better served by seeking out independent, verifiable, falsifiable evidence, rather that relying on quotes from dead scientist."
David LeRever
David LeRever
Free Space Impedance - Not Evidence of Aether (Engineering convenience)
https://physics.stackexchange.com/questions/79364/why-does-vacuum-have-a-nonzero-characteristic-impedance-towards-electromagnetic
https://physics.stackexchange.com/questions/79364/why-does-vacuum-have-a-nonzero-characteristic-impedance-towards-electromagnetic
MM Morley Not About Orbits
I know that relativity says there is not contraction inside the observers reference frame.
We are using LIGHT in MM.
You did not actually watch my stream or you wouldn’t keep saying this over and over surely, as I covered this and read all the way down to that part in the stream.
I showed Einstein saying it is a real physical effect. He says it is shortened for a coordinate system at rest relative to the sun. We are trying to detect the effect of ORBIT AROUND THE SUN. So again can you actually answer the question with specificity or if it just admit you do not know man instead of just constantly repeating yourself. All you have is to beat up a strawman over and over.. I know that it says it doesn’t shorten for an observer in the earths reference frame. So actually answer the questions with specificity please:
What SPECIFICALLY does relativity do to reconcile the negative result of MM?
Why does Einstein say the solution to the difficulty ALSO FROM THE STANDPOINT OF RELATIVITY THIS SOLUTION TO THE DIFFICULTY WAS THE RIGHT ONE?
Specifically, how does SR solve the difficulty in MM? How does relativity reconcile the negative results?
Is contraction/shortening a real physical phenomena according to SR?
Does the path of light shorten due to length contraction?
It is as if you simply do not actually understand it. You think just saying it doesn’t do it for us is some magic statement that avoids the question. Answers the questions directly please.
I know that relativity says there is not contraction inside the observers reference frame.
We are using LIGHT in MM.
You did not actually watch my stream or you wouldn’t keep saying this over and over surely, as I covered this and read all the way down to that part in the stream.
I showed Einstein saying it is a real physical effect. He says it is shortened for a coordinate system at rest relative to the sun. We are trying to detect the effect of ORBIT AROUND THE SUN. So again can you actually answer the question with specificity or if it just admit you do not know man instead of just constantly repeating yourself. All you have is to beat up a strawman over and over.. I know that it says it doesn’t shorten for an observer in the earths reference frame. So actually answer the questions with specificity please:
What SPECIFICALLY does relativity do to reconcile the negative result of MM?
Why does Einstein say the solution to the difficulty ALSO FROM THE STANDPOINT OF RELATIVITY THIS SOLUTION TO THE DIFFICULTY WAS THE RIGHT ONE?
Specifically, how does SR solve the difficulty in MM? How does relativity reconcile the negative results?
Is contraction/shortening a real physical phenomena according to SR?
Does the path of light shorten due to length contraction?
It is as if you simply do not actually understand it. You think just saying it doesn’t do it for us is some magic statement that avoids the question. Answers the questions directly please.
I showed Einstein himself saying that the contraction is a real PHYSICAL effect. There is length shortening for the person within the frame of reference bc EVERYTHING in that frame of reference contracts at the same rate relative to the motion. You fundamentally do not understand Relativity my guy. So answer this question SPECIFICALLY since you are so smart.
Why did Einstein say that the length contraction proposed for MM compensating the exact amount needed for the exceedingly small difference in time was the right one for Relativity as well? " Although the estimated difference between these two times is exceedingly small, Michelson and Morley performed an experiment involving interference in which this difference should have been clearly detectable. But the experiment gave a negative result — a fact very perplexing to physicists. Lorentz and FitzGerald rescued the theory from this difficulty by assuming that the motion of the body relative to the æther produces a contraction of the body in the direction of motion, the amount of contraction being just sufficient to compensate for the difference in time mentioned above. Comparison with the discussion in Section XII shows that from the standpoint ALSO of the THEORY OF RELATIVITY this solution of the difficulty was the RIGHT ONE." So how is their solution for the negative result in MM the right one according to Theory of Relativity and it said it contracted just the right amount but Relativity does not claim it contracted? hahaha.. the whole point is the contraction solution was the right one for relativity as well.. the difference is INTERPRETATION. Relativity says that EVERYTHING within that frame of reference shortens in the direction of motion. Relativity OBJECTIVELY says the Lorentz solution of contraction just the sufficient amount so solving the difficulty in lack of fringe shift was the right one.. its right there. Let it go. If that isn't true and Einstein is wrong then ANSWER THIS QUESTION:
Why did Einstein say that the length contraction proposed for MM compensating the exact amount needed for the exceedingly small difference in time was the right one for Relativity as well? " Although the estimated difference between these two times is exceedingly small, Michelson and Morley performed an experiment involving interference in which this difference should have been clearly detectable. But the experiment gave a negative result — a fact very perplexing to physicists. Lorentz and FitzGerald rescued the theory from this difficulty by assuming that the motion of the body relative to the æther produces a contraction of the body in the direction of motion, the amount of contraction being just sufficient to compensate for the difference in time mentioned above. Comparison with the discussion in Section XII shows that from the standpoint ALSO of the THEORY OF RELATIVITY this solution of the difficulty was the RIGHT ONE." So how is their solution for the negative result in MM the right one according to Theory of Relativity and it said it contracted just the right amount but Relativity does not claim it contracted? hahaha.. the whole point is the contraction solution was the right one for relativity as well.. the difference is INTERPRETATION. Relativity says that EVERYTHING within that frame of reference shortens in the direction of motion. Relativity OBJECTIVELY says the Lorentz solution of contraction just the sufficient amount so solving the difficulty in lack of fringe shift was the right one.. its right there. Let it go. If that isn't true and Einstein is wrong then ANSWER THIS QUESTION:

You're all familiar with this effect: suppose that you're standing in the rain, and there's no wind. Since the rain will fall vertically, you have to hold your umbrella straight up. But now start running. What happens? From your point of view, the rain will no longer fall vertically: you have to tilt your umbrella forward to keep your head dry. A similar phenomenon happens with light: the direction in which you see a beam of light depends on your velocity. This effect is called aberration.
For instance, suppose you have two stars, separated by an angle 𝜃 in a rest frame. If an observer is moving towards the star on the horizontal axis, then he will see the second star at an angle 𝜑, instead of 𝜃. If the velocity of the observer changes, then the angle 𝜑 changes, and the star will appear to 'wobble' with respect to stars at different positions.
The orbital velocity 𝑣≈30km/s of the Earth around the Sun causes an annual aberration: over the period of a year, every star and galaxy will appear to wobble on an ellipse, with a maximum displacement of 𝑣/𝑐≈20.5″ around their mean position, regardless of their distance to the Earth (unlike parallax, which does depend on distance). It was first observed by James Bradley in 1725, and is direct proof that the Earth orbits the Sun.
But there's another, much smaller aberration: a diurnal aberration, caused by the rotation of the Earth around its axis. The effect is greatest for an observer on the equator, who has an equatorial speed of 𝑣=0.465km/s, while an observer on the poles will see no effect. For an observer on the equator, the position of every star wobbles on a daily basis, with a maximum displacement of 𝑣/𝑐≈0.32″. It's an incredibly small effect, but it is measurable, and it has to be taken into account when doing high-precision astrometry. Moreover, it proves that the Earth does rotate.
Another proof that the Earth rotates, although it can only be measured with modern techniques: aberration.
For instance, suppose you have two stars, separated by an angle 𝜃 in a rest frame. If an observer is moving towards the star on the horizontal axis, then he will see the second star at an angle 𝜑, instead of 𝜃. If the velocity of the observer changes, then the angle 𝜑 changes, and the star will appear to 'wobble' with respect to stars at different positions.
The orbital velocity 𝑣≈30km/s of the Earth around the Sun causes an annual aberration: over the period of a year, every star and galaxy will appear to wobble on an ellipse, with a maximum displacement of 𝑣/𝑐≈20.5″ around their mean position, regardless of their distance to the Earth (unlike parallax, which does depend on distance). It was first observed by James Bradley in 1725, and is direct proof that the Earth orbits the Sun.
But there's another, much smaller aberration: a diurnal aberration, caused by the rotation of the Earth around its axis. The effect is greatest for an observer on the equator, who has an equatorial speed of 𝑣=0.465km/s, while an observer on the poles will see no effect. For an observer on the equator, the position of every star wobbles on a daily basis, with a maximum displacement of 𝑣/𝑐≈0.32″. It's an incredibly small effect, but it is measurable, and it has to be taken into account when doing high-precision astrometry. Moreover, it proves that the Earth does rotate.
Another proof that the Earth rotates, although it can only be measured with modern techniques: aberration.

Stellar aberration is different from stellar parallax, which is the shift of nearby stars relative to more distant stars due to the change in Earth’s position around the sun. The magnitude of stellar parallax depends on the distance of the stars, while stellar aberration affects every star by the same maximum shift. Both phenomena are direct evidence of heliocentrism.
Stellar aberration has the same annual cycle as Earth’s orbital period. It causes stars at the ecliptic poles to move in circles, those in the ecliptic plane to move in lines, and other stars in between to move in ellipses. The maximum shift of stars due to stellar aberration is the speed of Earth’s motion around the sun divided by the speed of light, which is 0.00099365 radians or 20.49552 arcseconds.
Stellar aberration has the same annual cycle as Earth’s orbital period. It causes stars at the ecliptic poles to move in circles, those in the ecliptic plane to move in lines, and other stars in between to move in ellipses. The maximum shift of stars due to stellar aberration is the speed of Earth’s motion around the sun divided by the speed of light, which is 0.00099365 radians or 20.49552 arcseconds.

So if you think about it, the Foucault pendulum is a kind of rotation meter, it's a way of measuring rotations.
A suitably placed Foucault pendulum can be used to detect the rotation of the earth, or the rotation of the earth around the sun, or in principle you could use a suitably oriented Foucault pendulum to measure the rotation of the solar system around the galaxy.
So this brings up the question, the Foucault pendulum is sensitive to rotation but rotation around what?
There seems to be a lot of speculation in physics and philosophy about that questions. Ernst Mach, 19th-20th century physicist put forward the conjecture that the Foucault pendulum is measuring rotation relative to the universe as a whole.
It makes an interesting connection between a local physics experiment here in this room and the universe as a whole.
The problem is how can this pendulum here somehow know something about the entire universe.
But this remains an unproven conjecture more in the realm of philosophy than physics.
A suitably placed Foucault pendulum can be used to detect the rotation of the earth, or the rotation of the earth around the sun, or in principle you could use a suitably oriented Foucault pendulum to measure the rotation of the solar system around the galaxy.
So this brings up the question, the Foucault pendulum is sensitive to rotation but rotation around what?
There seems to be a lot of speculation in physics and philosophy about that questions. Ernst Mach, 19th-20th century physicist put forward the conjecture that the Foucault pendulum is measuring rotation relative to the universe as a whole.
It makes an interesting connection between a local physics experiment here in this room and the universe as a whole.
The problem is how can this pendulum here somehow know something about the entire universe.
But this remains an unproven conjecture more in the realm of philosophy than physics.
Gravity as Pseudo/Apparent/Inertial Force
According to General Relativity a coordinate system on the surface of the earth is an upwards accelerated, non-inertial reference frame , because the surface of the earth prevents the system from following the free fall trajectory (Geodesic) of the curved Spacetime produced by the mass of the earth. In an upwards accelerated reference frame objects appear to be accelerated downwards. So there is an apparent downward force called gravity.
Pseudo forces like gravity, centrifugal, and coriolis forces have to be taken into account like any other forces. They have exactly the same effect on motion, no matter how they are caused.
According to General Relativity a coordinate system on the surface of the earth is an upwards accelerated, non-inertial reference frame , because the surface of the earth prevents the system from following the free fall trajectory (Geodesic) of the curved Spacetime produced by the mass of the earth. In an upwards accelerated reference frame objects appear to be accelerated downwards. So there is an apparent downward force called gravity.
Pseudo forces like gravity, centrifugal, and coriolis forces have to be taken into account like any other forces. They have exactly the same effect on motion, no matter how they are caused.

General relativity is IDENTICAL with Newton gravity to lowest order in the power series in x=v/c known as the post Newtonian expansion, introduced by Einstein in 1916
In Newtonian dynamics, the gravitational potential energy is Not a Force. However the Force we call “gravity” can be calculated from the gravitational potential energy.
Einstein’s mechanics. space-time bending is called “gravity” but it is Not a Force. However, there is a force that can be calculated from space-time bending. This Einstein force is usually called “gravity” in the science literature.
It is obviously confusing to apply the same term to two completely different things, but many terminological atrocities have become entrenched in the science literature.
“mass-driven-space time-bending-that-is-not-a-force-but-from-which-a-force-can-be-calculated”.
In Newtonian dynamics, the gravitational potential energy is Not a Force. However the Force we call “gravity” can be calculated from the gravitational potential energy.
Einstein’s mechanics. space-time bending is called “gravity” but it is Not a Force. However, there is a force that can be calculated from space-time bending. This Einstein force is usually called “gravity” in the science literature.
It is obviously confusing to apply the same term to two completely different things, but many terminological atrocities have become entrenched in the science literature.
“mass-driven-space time-bending-that-is-not-a-force-but-from-which-a-force-can-be-calculated”.

This comic presents a slightly orthogonal argument to the one on the question: the subject (James Bond) is arguing that the “centrifugal force doesn't exist”.
The villain mocks him by saying:
“a laughable claim, Mister Bond, perpetuated by overzealous teachers of science. Simply construct Newton's laws in a rotating system and you will see a centrifugal force term appear as plain as day”
Many people claim that “in general relativity, Gravity is not a force”. This is a well intentioned claim — and it has a nugget of some truth in it — but, as the comic says, it is an “overzealous claim”. It is a claim which takes an actual bit of science, and runs screaming with it naked through the streets hooting incoherently, until all that remains is nonsense. It's the sort of thing which is said specifically because it defies all human expectation.
So, let's get one thing straight: Pick up a heavy object, and drop it on your foot.
Hurts, right?
You'd have to be some kind of madman to argue that there wasn't a force or two involved in that! It's blindingly obvious to everyone that gravity is a force.
What is true is that, in the framework of General Relativity, gravity is a manifestation of the underlying geometry of space-time. Where space-time deviates from a flat, Minkowskian description, we observe the phenomenon known as “gravity". This differs hugely from the way the other forces we think about work, which (in a simplistic term), is via potential energy fields, and the gradients thereof. It would, therefore, be tempting to state that, since gravity arises from the shape of space itself, it's not a “proper force”, like the others.
But, nonetheless, if you construct your equations of motion, you end up with things that are, undeniably, forces. You get effective potentials, and if you take the derivative of them you get … something that changes the direction of an object. Now, again, it is true that you can make these forces vanish by choosing a different observer, a different set of coordinates with which to measure the motion. But does that mean it's “not a force?” It seems ludicrous that because there is one specific frame of reference which doesn't see a force to ignore all of the other frames which, evidently, do see a force. It's throwing the baby out with the bathwater, and then throwing the bath out as well.
What the centrifugal/centripetal construction tells us is that, even in classical, “normal” physics, it is perfectly normal for forces to vanish when you change your point of view. Someone being crushed to death by a centrifuge is not going to be impressed when you tell them that there's “not a force” which is killing them! The correct conclusion is not that, because we can make them vanish by changing our coordinates, these things are not “real”, but that forces are not a universally agreed upon quantity.
It doesn't make sense to deny the overwhelming force-ness (technical term) of these objects, because they are really, really obviously forces. Even when they arise only due to a particular coordinate choice in a particular part of a curved spacetime — it is ludicrous just to say “nah, not a force”. You can make a distinction (they're often called “pseudoforces”), but to deny that they are what they are is….just playing word games. It's just that it's a very complicated force that arises in different ways depending on who looks at it.
The villain mocks him by saying:
“a laughable claim, Mister Bond, perpetuated by overzealous teachers of science. Simply construct Newton's laws in a rotating system and you will see a centrifugal force term appear as plain as day”
Many people claim that “in general relativity, Gravity is not a force”. This is a well intentioned claim — and it has a nugget of some truth in it — but, as the comic says, it is an “overzealous claim”. It is a claim which takes an actual bit of science, and runs screaming with it naked through the streets hooting incoherently, until all that remains is nonsense. It's the sort of thing which is said specifically because it defies all human expectation.
So, let's get one thing straight: Pick up a heavy object, and drop it on your foot.
Hurts, right?
You'd have to be some kind of madman to argue that there wasn't a force or two involved in that! It's blindingly obvious to everyone that gravity is a force.
What is true is that, in the framework of General Relativity, gravity is a manifestation of the underlying geometry of space-time. Where space-time deviates from a flat, Minkowskian description, we observe the phenomenon known as “gravity". This differs hugely from the way the other forces we think about work, which (in a simplistic term), is via potential energy fields, and the gradients thereof. It would, therefore, be tempting to state that, since gravity arises from the shape of space itself, it's not a “proper force”, like the others.
But, nonetheless, if you construct your equations of motion, you end up with things that are, undeniably, forces. You get effective potentials, and if you take the derivative of them you get … something that changes the direction of an object. Now, again, it is true that you can make these forces vanish by choosing a different observer, a different set of coordinates with which to measure the motion. But does that mean it's “not a force?” It seems ludicrous that because there is one specific frame of reference which doesn't see a force to ignore all of the other frames which, evidently, do see a force. It's throwing the baby out with the bathwater, and then throwing the bath out as well.
What the centrifugal/centripetal construction tells us is that, even in classical, “normal” physics, it is perfectly normal for forces to vanish when you change your point of view. Someone being crushed to death by a centrifuge is not going to be impressed when you tell them that there's “not a force” which is killing them! The correct conclusion is not that, because we can make them vanish by changing our coordinates, these things are not “real”, but that forces are not a universally agreed upon quantity.
It doesn't make sense to deny the overwhelming force-ness (technical term) of these objects, because they are really, really obviously forces. Even when they arise only due to a particular coordinate choice in a particular part of a curved spacetime — it is ludicrous just to say “nah, not a force”. You can make a distinction (they're often called “pseudoforces”), but to deny that they are what they are is….just playing word games. It's just that it's a very complicated force that arises in different ways depending on who looks at it.
NOTE: There is often a fallacy motivated by the Equivalence Principle, in which people ignore the different speed rate of proper time inside the free-falling elevator. Yes, the man inside the free-falling elevator is unable to distinguish if he is in a gravitational field (but in free fall), or if he is floating in interstellar space, far away from any mass. But in the second case, the man inside the elevator is ageing faster that the one that is in free fall (orbit) around the Sun. This is another kind of twins paradox that is often forgotten.
https://www.wikiwand.com/en/Lense%E2%80%93Thirring_effect
These are the equations witsit needs to use to get his frame dragging effect from a large rotating mass to create Coriolis and Centrifual forces.
Then he needs to model it on a flat earth, and account for the huge mass gravtitational effects upwards.
Relative to What? Cosmic background...
Rotation of Earth
Earth around Sun
Sun Around Galaxy
Precession
Nutation
Rotation
Wobbles (daily and yearly)
Lense Thirring precession
Geodetic Precession (object orbiting central mass).
But if motion of pendulum here influenced by stars out there, how can the stars wobble around the earth...
These are the equations witsit needs to use to get his frame dragging effect from a large rotating mass to create Coriolis and Centrifual forces.
Then he needs to model it on a flat earth, and account for the huge mass gravtitational effects upwards.
Relative to What? Cosmic background...
Rotation of Earth
Earth around Sun
Sun Around Galaxy
Precession
Nutation
Rotation
Wobbles (daily and yearly)
Lense Thirring precession
Geodetic Precession (object orbiting central mass).
But if motion of pendulum here influenced by stars out there, how can the stars wobble around the earth...
What is a Foucault pendulum eventually rotating around? There is no answer to that question. Moreover, it is not yet clear whether the question makes sense or not.
The most close answer to your question may be found in our motion relative to the Background radiation, found by means of the dipole anisotropy of the CBR. This is the closest thing that there is, to an "absolute reference frame" but it makes sense only for us. Other distant observers in out expanding Universe will have a completely different perception.
As for Mach's principle, let me stress that it is merely a philosophical idea, that may or may not some day lead to a real theory. It is neither correct nor incorrect.
The most close answer to your question may be found in our motion relative to the Background radiation, found by means of the dipole anisotropy of the CBR. This is the closest thing that there is, to an "absolute reference frame" but it makes sense only for us. Other distant observers in out expanding Universe will have a completely different perception.
As for Mach's principle, let me stress that it is merely a philosophical idea, that may or may not some day lead to a real theory. It is neither correct nor incorrect.
The BIG Problem with invoking anitquated quotes to prove a stationary Earth in 2022
The Big Problem is the Well Validated Big Bang Cosmology
I-nye-so-tropy
1989, is NASA's Cosmic Background Explorer, or COBE (left panel). Two of COBE's principal scientists earned the Nobel Prize in Physics in 2006 for the mission's evidence supporting the big bang theory, and for its demonstration that tiny variations in the ancient light reveal information about the state of the universe.
Wilkinson Microwave Anisotropy Probe, or WMAP (middle panel). This mission, launched in 2001, found strong evidence for inflation, the very early epoch in our universe when it expanded dramatically in size, and measured basic traits of our universe better than ever before.
The most advanced satellite yet of this type is Planck, a European Space Agency mission with significant NASA contributions. Planck, launched in 2009, images the sky with more than 2.5 times greater resolution than WMAP,
The Big Problem is the Well Validated Big Bang Cosmology
I-nye-so-tropy
1989, is NASA's Cosmic Background Explorer, or COBE (left panel). Two of COBE's principal scientists earned the Nobel Prize in Physics in 2006 for the mission's evidence supporting the big bang theory, and for its demonstration that tiny variations in the ancient light reveal information about the state of the universe.
Wilkinson Microwave Anisotropy Probe, or WMAP (middle panel). This mission, launched in 2001, found strong evidence for inflation, the very early epoch in our universe when it expanded dramatically in size, and measured basic traits of our universe better than ever before.
The most advanced satellite yet of this type is Planck, a European Space Agency mission with significant NASA contributions. Planck, launched in 2009, images the sky with more than 2.5 times greater resolution than WMAP,

There are experimental evidences of absolute motion of the Earth around the Sun. There is a dipole anisotropy in fine measures of the Background Radiation temperature that is known from the analysis of the COBE satellite measures, in the early 90s.
In order to make the adequate corrections, so that the Cosmic Background Radiation "seems" isotropic, the absolute velocity of the Local Group against the Cosmic Background Radiation must be accounted for, but that correction depends on the month of the year, because a small part of the correction comes from the orbital speed of the Earth around the barycentre of the Solar System (among other terms).
That small part of the corrections needed is exactly what you would expect if you assumed that is the Earth who is going around the Sun, and not vice versa.
(the cosmic background dipole anisotropy, image from map.gsfc.nasa.gov)
In order to make the adequate corrections, so that the Cosmic Background Radiation "seems" isotropic, the absolute velocity of the Local Group against the Cosmic Background Radiation must be accounted for, but that correction depends on the month of the year, because a small part of the correction comes from the orbital speed of the Earth around the barycentre of the Solar System (among other terms).
That small part of the corrections needed is exactly what you would expect if you assumed that is the Earth who is going around the Sun, and not vice versa.
(the cosmic background dipole anisotropy, image from map.gsfc.nasa.gov)

Here is an extract from the abstract of the quoted paper:
https://arxiv.org/pdf/astro-ph/9312056.pdf
We present a determination of the cosmic microwave background dipole amplitude and direction from the COBE Differential Microwave Radiometers (DMR) first year of data (...) The implied velocity of the Local Group with respect to the CMB rest frame is 𝑣𝐿𝐺=627±22𝑘𝑚𝑠−1 toward (...). DMR has also mapped the dipole anisotropy resulting from the Earth's orbital motion about the Solar System barycenter, yielding a measurement of the monopole CMB temperature (...) 𝑇0=2.75±0.05𝐾
This doesn't mean however, that there is an absolute reference frame in the Universe. Other comoving observers will detect another dipole anisotropy. The Last Scattering Surface, as well as the cosmological horizons are different for different comoving observers. But nevertheless it proves that it is the Earth that moves around the Sun, and not vice versa. Since the 90s this is no more a philosophical issue: WE are moving certainly, absolutely, surely and gloriously, around the Sun.
https://arxiv.org/pdf/astro-ph/9312056.pdf
We present a determination of the cosmic microwave background dipole amplitude and direction from the COBE Differential Microwave Radiometers (DMR) first year of data (...) The implied velocity of the Local Group with respect to the CMB rest frame is 𝑣𝐿𝐺=627±22𝑘𝑚𝑠−1 toward (...). DMR has also mapped the dipole anisotropy resulting from the Earth's orbital motion about the Solar System barycenter, yielding a measurement of the monopole CMB temperature (...) 𝑇0=2.75±0.05𝐾
This doesn't mean however, that there is an absolute reference frame in the Universe. Other comoving observers will detect another dipole anisotropy. The Last Scattering Surface, as well as the cosmological horizons are different for different comoving observers. But nevertheless it proves that it is the Earth that moves around the Sun, and not vice versa. Since the 90s this is no more a philosophical issue: WE are moving certainly, absolutely, surely and gloriously, around the Sun.

Planets - Show me the Orbits!
**The earth is not stationary & (and it sure isn't flat)!**
Flat-Earthers claim that Earth is stationary. In reality, from observing the planets’ motion, the most plausible explanation is that all planets, including Earth, are in motion around the Sun.
Planets appear to move near the ecliptic —the line that marks the annual path of the Sun against background stars. From these motions, it is obvious that Venus and Mercury are in motion around the Sun. And the motion of the other planets can only be explained if Earth is in motion around the Sun. Otherwise you end up with the ole' epicycle problem of the Ptolemaic geocentric model. A problem that the heliocentric model corrected and simplified , but sadly a problem the flat earth model makes even worse because at least the Geocentric model had the earth as a sphere!
Ancient Greeks called these lights planētes asteres, "wandering stars" or simply planētai, "wanderers"), from which today's word "planet" was derived.
This is mars photographed once a week over a period of months. Rather than traveling in a straight line across the background of the stars, it occasionally changes direction and loops back on itself. It is very hard to explain these retrograde loops if the earth is at the center of the universe.
Took over 2000 years to work this retrograde motion, key is understanding the Sun is at the center of the solar system, not the earth.
**The earth is not stationary & (and it sure isn't flat)!**
Flat-Earthers claim that Earth is stationary. In reality, from observing the planets’ motion, the most plausible explanation is that all planets, including Earth, are in motion around the Sun.
Planets appear to move near the ecliptic —the line that marks the annual path of the Sun against background stars. From these motions, it is obvious that Venus and Mercury are in motion around the Sun. And the motion of the other planets can only be explained if Earth is in motion around the Sun. Otherwise you end up with the ole' epicycle problem of the Ptolemaic geocentric model. A problem that the heliocentric model corrected and simplified , but sadly a problem the flat earth model makes even worse because at least the Geocentric model had the earth as a sphere!
Ancient Greeks called these lights planētes asteres, "wandering stars" or simply planētai, "wanderers"), from which today's word "planet" was derived.
This is mars photographed once a week over a period of months. Rather than traveling in a straight line across the background of the stars, it occasionally changes direction and loops back on itself. It is very hard to explain these retrograde loops if the earth is at the center of the universe.
Took over 2000 years to work this retrograde motion, key is understanding the Sun is at the center of the solar system, not the earth.

Stellar motion would imply we're in the place where the Big Bang occurred while everything else is speeding away from us. I can see how this would be a worthwile explanation for a creationist, but it doesn't really make much sense building just on physics.
Doppler Effect has the same issue - it assumes that every star we can see moves in a speed proportional to distance with respect to us. That's extremely Sun-centric, and doesn't really work if you accept that e.g. stars in our galaxy orbit around its center, including us.
Gravitation of course does have effect on wavelength, but it's by far not enough for common stars, much less planets. And of course, the effect is only at work when you're in the gravitational well - this would imply that the Sun is again at the center of everything, with everything else orbitting around it.
Photon interaction - never been observed, doesn't really play well with accepted theories of electro-magnetism and photons. With the exception of - the expansion of space itself. Yes, photons are losing energy, that's why they're red-shifted. Even though there is a certain preference for photons to fill in similar states, this mostly manifests as a tendency for self-collimation. Interacting photons would not explain why the red-shift is correlated with distance either.
The others work in a similar fashion. Slowing of light would have huge effects on every interaction in the universe - which would mean that even things like water wouldn't be stable over time, they would change their behaviour rather a lot. Combined with the proposed age of ~6000 years for the universe, with humans from the very beginning, this is just absurd. The assumptions made by theory of relativity make this even more crazy - in relativity, speed of light is basically the maximum speed of propagation of information. So this hinges on older models of the speed of light, independent of the space-time itself.
Galaxies spiraling towards the Earth was already handled in the Gravitational red-shift explanation and the Doppler effect.
All in all, you can see why a creationist-proponent would like those theories. They mostly work on the basis that we are at the center of everything, and everything else revolves around us. It's the good old Earth-centric solar system model again, just dressed in the universe this time.
The problem is, addressing every single hypothesis put forward by people lacking in basic science practice and knowledge is fighting windmills. You can always imagine sillier and sillier explanations, and when people finally get tired of responding, you'll just say "See? The scientists have no explanation for that!" It's an uphill battle, and somewhat pointless, really.
Don't forget that when you propose an alternative theory/hypothesis, you need to explain everything the old theory did. If we find out that photons travel at lower or higher speeds than the speed of light, it might put relativity out of the question, but we'll still have to find out why it works almost all the time we've checked. It's possible to "overthrow" a well established theory, but most often, you're only adding to what's already there. For example, Newton's law of gravity is wrong, but it's not thrown out outright - it's simply explained differently, and broadened to explain new observations. Most of the time, it works well enough. If it starts contradicting your observations (like the famous precession of Mercury issue), you start refining - in this case, Einstein pretty much redefined the whole universe. But it didn't make the old theory wrong outright - just incomplete. Creationist hypothesis tend to ignore this completely - they focus on one pet theory, and ignore the other explanations that need to be done to maintain a consistent model.
Doppler Effect has the same issue - it assumes that every star we can see moves in a speed proportional to distance with respect to us. That's extremely Sun-centric, and doesn't really work if you accept that e.g. stars in our galaxy orbit around its center, including us.
Gravitation of course does have effect on wavelength, but it's by far not enough for common stars, much less planets. And of course, the effect is only at work when you're in the gravitational well - this would imply that the Sun is again at the center of everything, with everything else orbitting around it.
Photon interaction - never been observed, doesn't really play well with accepted theories of electro-magnetism and photons. With the exception of - the expansion of space itself. Yes, photons are losing energy, that's why they're red-shifted. Even though there is a certain preference for photons to fill in similar states, this mostly manifests as a tendency for self-collimation. Interacting photons would not explain why the red-shift is correlated with distance either.
The others work in a similar fashion. Slowing of light would have huge effects on every interaction in the universe - which would mean that even things like water wouldn't be stable over time, they would change their behaviour rather a lot. Combined with the proposed age of ~6000 years for the universe, with humans from the very beginning, this is just absurd. The assumptions made by theory of relativity make this even more crazy - in relativity, speed of light is basically the maximum speed of propagation of information. So this hinges on older models of the speed of light, independent of the space-time itself.
Galaxies spiraling towards the Earth was already handled in the Gravitational red-shift explanation and the Doppler effect.
All in all, you can see why a creationist-proponent would like those theories. They mostly work on the basis that we are at the center of everything, and everything else revolves around us. It's the good old Earth-centric solar system model again, just dressed in the universe this time.
The problem is, addressing every single hypothesis put forward by people lacking in basic science practice and knowledge is fighting windmills. You can always imagine sillier and sillier explanations, and when people finally get tired of responding, you'll just say "See? The scientists have no explanation for that!" It's an uphill battle, and somewhat pointless, really.
Don't forget that when you propose an alternative theory/hypothesis, you need to explain everything the old theory did. If we find out that photons travel at lower or higher speeds than the speed of light, it might put relativity out of the question, but we'll still have to find out why it works almost all the time we've checked. It's possible to "overthrow" a well established theory, but most often, you're only adding to what's already there. For example, Newton's law of gravity is wrong, but it's not thrown out outright - it's simply explained differently, and broadened to explain new observations. Most of the time, it works well enough. If it starts contradicting your observations (like the famous precession of Mercury issue), you start refining - in this case, Einstein pretty much redefined the whole universe. But it didn't make the old theory wrong outright - just incomplete. Creationist hypothesis tend to ignore this completely - they focus on one pet theory, and ignore the other explanations that need to be done to maintain a consistent model.
Sir George Stokes proposed that the Aether is at rest in relation to the surface of the earth
From the 1887 paper by Michelson and Morley, If you were to ignore all other evidence of rotation like opposite rotating celestial poles, stellar parallax, the precession of the equinoxes, Coriolis, Eötvös, etc. one could propose that the earth is stationary. However, in 1925, Michelson, Gale, and Pearson published another experiment that measured the difference in time taken for light to travel in opposite directions around a large rectangle.
Flat earthers interpret this as the aether swirling around the surface of the earth.
If the earth and aether are stationary according to Michelson-Morley, then the aether cannot simultaneously be swirling around according to Michelson-Gale. You can’t have both.
https://www.universetoday.com/22912/more-evidence-earth-is-not-center-of-universe/
From the 1887 paper by Michelson and Morley, If you were to ignore all other evidence of rotation like opposite rotating celestial poles, stellar parallax, the precession of the equinoxes, Coriolis, Eötvös, etc. one could propose that the earth is stationary. However, in 1925, Michelson, Gale, and Pearson published another experiment that measured the difference in time taken for light to travel in opposite directions around a large rectangle.
Flat earthers interpret this as the aether swirling around the surface of the earth.
If the earth and aether are stationary according to Michelson-Morley, then the aether cannot simultaneously be swirling around according to Michelson-Gale. You can’t have both.
https://www.universetoday.com/22912/more-evidence-earth-is-not-center-of-universe/
Of course Witsit Knows this is a problem, because he invokes the moving Aether to explain rotational effects on earth. So he has to find ways to bring in a fringe shift that dozens of studies show doesn't exist... Well except for one, the Infamous
Airforce Study 1986
Airforce Study 1986
But in 2012 Doug Marett actually repeated the experiment, and what he found is fascinating.
Over the course of 18 months Marett recreated the Silvertooth experiment, and confirmed the result. There was an apparent shift in wavelength that varied with the orientation of Earth, and it did seem to show an apparent motion of Earth in agreement with Silvertooth's intial findings. But looking at the data more carefully, Marett also found that there was a lot of fluctuation in the data.
If Silvertooth was right, the wavelength variations should follow sidereal time, not solar time. Marett found there was so much noise in the data, the variation in wavelengths could be made to agree with either sidereal or solar time. Digging into things more closely, he saw a correlation between the observed wavelength shift and small fluctuations in the temperature of the room. The change in temperature was shifting the alignment of the experiment laser, causing the apparent shift Silvertooth saw. Marett also found that the calculated motion of the Earth only worked because Silvertooth assumed the data measured an actual wavelength shift. Silvertooth's results were real, but his conclusions were wrong.
Over the course of 18 months Marett recreated the Silvertooth experiment, and confirmed the result. There was an apparent shift in wavelength that varied with the orientation of Earth, and it did seem to show an apparent motion of Earth in agreement with Silvertooth's intial findings. But looking at the data more carefully, Marett also found that there was a lot of fluctuation in the data.
If Silvertooth was right, the wavelength variations should follow sidereal time, not solar time. Marett found there was so much noise in the data, the variation in wavelengths could be made to agree with either sidereal or solar time. Digging into things more closely, he saw a correlation between the observed wavelength shift and small fluctuations in the temperature of the room. The change in temperature was shifting the alignment of the experiment laser, causing the apparent shift Silvertooth saw. Marett also found that the calculated motion of the Earth only worked because Silvertooth assumed the data measured an actual wavelength shift. Silvertooth's results were real, but his conclusions were wrong.
Aether was the hypothetical material that fills the region of space. It was assumed to be the medium that allows light and gravity to propagate in space. Throughout the late 1800s and early 1900s, some experiments were carried out to prove if the aether exists.
Flat-Earthers (and geocentrists alike) often use the results of these experiments to support their case that the Earth is stationary. But they are wrong. These experiments were conducted to prove if the Aether theory, or if one of its competing hypotheses —like the Special Relativity— better explains reality.
In 1871, George Airy attempted to measure the drag of light that would change the stellar aberration of light by using a water-filled telescope, instead of an air-filled one. His observation did not indicate the change exists and does not support the Aether drag hypothesis, hence the popular name “Airy’s failure.” It does not support a flat & stationary Earth as the underlying phenomenon —the annual stellar aberration— can only occur if the Earth is in motion around the Sun.
The Michelson-Morley experiment in 1887 proved that if the Earth is in motion, then Aether could not exist. This experiment alone cannot confirm if the Earth is or is not in motion, but that does not stop flat-Earthers. The fact that the Earth is in motion had to be concluded from other observations.
Georges Sagnac in 1913 conducted an experiment where he rotated his interferometer. He concluded the Aether exists, but only because he was unaware of what we call now the Sagnac effect. This effect is used today in optical gyroscopes, and cannot possibly be utilized had the Aether theory is correct.
The Michelson–Gale–Pearson experiment (1926) was a very large interferometer designed to detect Earth’s rotation by measuring the resulting Sagnac effect. The experiment was successful and confirmed the angular velocity due to Earth’s rotation.
Flat-Earthers (and geocentrists alike) often use the results of these experiments to support their case that the Earth is stationary. But they are wrong. These experiments were conducted to prove if the Aether theory, or if one of its competing hypotheses —like the Special Relativity— better explains reality.
In 1871, George Airy attempted to measure the drag of light that would change the stellar aberration of light by using a water-filled telescope, instead of an air-filled one. His observation did not indicate the change exists and does not support the Aether drag hypothesis, hence the popular name “Airy’s failure.” It does not support a flat & stationary Earth as the underlying phenomenon —the annual stellar aberration— can only occur if the Earth is in motion around the Sun.
The Michelson-Morley experiment in 1887 proved that if the Earth is in motion, then Aether could not exist. This experiment alone cannot confirm if the Earth is or is not in motion, but that does not stop flat-Earthers. The fact that the Earth is in motion had to be concluded from other observations.
Georges Sagnac in 1913 conducted an experiment where he rotated his interferometer. He concluded the Aether exists, but only because he was unaware of what we call now the Sagnac effect. This effect is used today in optical gyroscopes, and cannot possibly be utilized had the Aether theory is correct.
The Michelson–Gale–Pearson experiment (1926) was a very large interferometer designed to detect Earth’s rotation by measuring the resulting Sagnac effect. The experiment was successful and confirmed the angular velocity due to Earth’s rotation.
Flat earthers misrepresent Airy's experiment and the implications. What Airy, and Michelson-Morley, showed was there is no aether that we are moving through.
Michelson-Gale-Pearson, Sagnac, Compton, et al. proved Earth's motion around the Sun and Rotation about an axis. The observed annual stellar aberration, or apparent motion of celestial objects about their true positions, is dependent on the velocity of the observer which also proves the Earth is moving. What finally accounted for all observations is Einstein's Relativity.
Michelson-Gale-Pearson, Sagnac, Compton, et al. proved Earth's motion around the Sun and Rotation about an axis. The observed annual stellar aberration, or apparent motion of celestial objects about their true positions, is dependent on the velocity of the observer which also proves the Earth is moving. What finally accounted for all observations is Einstein's Relativity.
Michelson's terse description of the experiment: "The interpretation of these results is that there is no displacement of the interference bands. ... The result of the hypothesis of a stationary ether is thus shown to be incorrect." (A. A. Michelson, Am. J. Sci, 122, 120 (1881))
Further, with respect to Einstein saying Earth's orbit around the Sun can't be detected, Witsit is cherry picking from that quote as well and taking it out of context. The following is the actual quote along with the preceding paragraph to make the context clear: "Then I myself wanted to verify the flow of the ether with respect to the Earth, in other words, the motion of the Earth. When I first thought about this problem, I did not doubt the existence of the ether or the motion of the Earth through it. I thought of the following experiment using two thermocouples: Set up mirrors so that the light from a single source is to be reflected in two different directions, one parallel to the motion of the Earth and the other antiparallel. If we assume that there is an energy difference between the two reflected beams, we can measure the difference in the generated heat using two thermocouples. Although the idea of this experiment is very similar to that of Michelson, I did not put this experiment to the test. While I was thinking of this problem in my student years, I came to know the strange result of Michelson's experiment. Soon I came to the conclusion that our idea about the motion of the Earth with respect to the ether is incorrect, if we admit Michelson's null result as a fact. This was the first path which led me to the special theory of relativity. Since then I have come to believe that the motion of the Earth cannot be detected by any optical experiment, though the Earth is revolving around the Sun." Witsit is omitting the last part where Einstein acknowledges that Earth is revolving around the Sun. Also, from these two paragraphs, the context is more clear. Einstein initially thought the ether existed and Earth is moving through it. But since Michelson's experiment to detect Earth's motion through the ether failed, Einstein felt that no optical experiment can detect it because light needs ether as a medium for propagation, but that propagation can't be detected. However, later on Einstein realized that the ether doesn't exist and this led to the formulation of his Special Theory of Relativity.
In 1881, Albert A. Michelson experimented to prove the existence of aether. Aether was a hypothesized material that fills the region of the universe. Scientists knew light is a form of a wave, and because all other waves require a medium to propagate, they formulated the aether hypothesis, in which light can propagate. However, Michelson’s attempt produced a null result. Michelson concluded that the hypothesis of a stationary aether is erroneous.
Ether is a frame, in which an observer measures the speed of light to be exactly c. If Galilean transformations really applied to light, then there would be one and only one on which the speed of light is exactly c. That is there is a unique inertial system in which the so called ether is at rest. Only way Galilean transformations and Maxwells work is if there is a unique and privileged frame of reference (the "ether" frame) in which Maxwell's equations are valid and in which light is propagated at a speed c.
Ether is a frame, in which an observer measures the speed of light to be exactly c. If Galilean transformations really applied to light, then there would be one and only one on which the speed of light is exactly c. That is there is a unique inertial system in which the so called ether is at rest. Only way Galilean transformations and Maxwells work is if there is a unique and privileged frame of reference (the "ether" frame) in which Maxwell's equations are valid and in which light is propagated at a speed c.
1. Stationary Ether, no contraction: what was originally thought as the medium or reference frame from which light propagated.
The experimental results showed no shift in the fringe patterns. The only possible conclusion is the earth is traveling with a speed v=0 relative to the ether, to which Michelson himself said was preposterous.
**Should be a shift in the fringe pattern. ΔN = .4 if there is a stationary ether (v/c = 10^-4 based on earth's orbital velocity of 30,000 m/s and light going 3x10^8 m/s.
Another possibility is to conclude the speed of light is the same in all directions in every inertial system**. For this fact would lead to ΔN = 0 in the equal arm experiment, the "downstream/upstream" and cross stream speeds both being c, rather than |c + v| or |c - v|. However such a conclusion being incompatible with Galilean (velocity) transformations, seemed to be too drastic philosophy at the time. If the measured speed of light did not depend on the motion of the observer, all inertial systems would be equivalent for a propagation of light and there would be no experimental evidence to indicate the existence of a unique inertial system, that is, the ether. Therefore to "save the ether" and still explain the Michelson-Morley result, scientists suggested alternative hypotheses which fell under two broad categories.
**Note: Cherenkov (Cher -ain - koff) radiation is not faster Than the speed of light in a vacuum.
J.P. Cedarholm, C.H. Townes carried out an "ether-wind" experiment using microwaves in which they showed an improvement of 50 in precision over the best previous MM type. The null result is well established.
The experimental results showed no shift in the fringe patterns. The only possible conclusion is the earth is traveling with a speed v=0 relative to the ether, to which Michelson himself said was preposterous.
**Should be a shift in the fringe pattern. ΔN = .4 if there is a stationary ether (v/c = 10^-4 based on earth's orbital velocity of 30,000 m/s and light going 3x10^8 m/s.
Another possibility is to conclude the speed of light is the same in all directions in every inertial system**. For this fact would lead to ΔN = 0 in the equal arm experiment, the "downstream/upstream" and cross stream speeds both being c, rather than |c + v| or |c - v|. However such a conclusion being incompatible with Galilean (velocity) transformations, seemed to be too drastic philosophy at the time. If the measured speed of light did not depend on the motion of the observer, all inertial systems would be equivalent for a propagation of light and there would be no experimental evidence to indicate the existence of a unique inertial system, that is, the ether. Therefore to "save the ether" and still explain the Michelson-Morley result, scientists suggested alternative hypotheses which fell under two broad categories.
**Note: Cherenkov (Cher -ain - koff) radiation is not faster Than the speed of light in a vacuum.
J.P. Cedarholm, C.H. Townes carried out an "ether-wind" experiment using microwaves in which they showed an improvement of 50 in precision over the best previous MM type. The null result is well established.
2. Stationary Ether, Lorenz contraction: All bodies contracted relative to a stationary ether by a factor of 1/sqrt(1-v^2/c^2). Interferometer of differing lengths should show a shift in fringes but doesn't.
3. Ether Drag: Ether attached to appreciable bodies. Another attempt to retain the notion of a preferred ether frame. This hypothesis assumed that the ether frame was attached to all bodies of finite mass, that is, dragged along with such bodies. The assumption of a local ether would automatically give a null result in the Michelson-Morley experiment. It's attraction lay in the fact that it did not require modifications of classical mechanics or electromagnetism.
However there were two well established effects which contradicted the ether drag hypothesis: stellar aberration and the Fizeau convection coefficient.
However there were two well established effects which contradicted the ether drag hypothesis: stellar aberration and the Fizeau convection coefficient.
http://curious.astro.cornell.edu/physics/41-our-solar-system/the-earth/orbit/88-is-there-a-proof-that-earth-moves-intermediate
Stellar Aberration and Parallax
How do we know that Earth and other planets go around the Sun, and not the opposite?
The ancient astronomer Aristarchus thought that Earth goes around the Sun since he discovered that the Sun is much bigger than Earth. Copernicus (who is usually credited with the idea that planets go around the Sun) thought that Solar system centered on the Sun is more logical and beautiful, but had no definite proof. Kepler discovered that laws governing of orbits become much more simple if the Sun is in their center. Newton has shown that this is caused by the universal law of gravity. If gravity works, Earth and other planets have to go around the Sun, because it is much heavier.
There was no straightforward demonstration of Earth's motion until 1725 when James Bradley discovered stellar aberration. This is (apparent) yearly change in positions of all stars in the sky due to Earth's own motion. Aberration arises due to adding up of the speed of light coming from the star and Earth's own speed. This is a very complex phenomenon and its description requires some math.
Another, much simpler, consequence of Earth's motion is stellar parallax. If Earth changes its position relative to the stars, then the stars should appear to change position in the course of the year.
A common experiment illustrating parallax is just looking at a close object (a finger, a pencil etc) with one eye at the time. When you switch from one to the other eye, the object will appear to move against the background. Closer the object is to your eyes, more pronounced the effect is.
Parallax should not be confused with aberration: parallax arises from the change of Earth's position and depends on the distance to the star, while aberration is caused by Earth's great speed and does not depend on how far the star is.
Parallax of a star was first measured by Bessel in 1838. It was not measured before because this change of star's apparent position is very small (the stars are very far from us). This was a very important discovery because Aristotle himself mentioned the lack of observable stellar parallax as the proof that the Earth is not moving (he didn't have a telescope and didn't know that the stars are so distant).
A third discovery demonstrating Earth's motion was that of Doppler effect. The wavelength of the light that we receive from objects moving relative to us becomes a little shorter (i.e. bluer) when we approach the source and becomes longer (i.e. redder) when we move away from the source. When Earth moves toward a star, the star will appear slightly bluer (only high-tech instruments can measure this) while it will appear redder when Earth is on the other side of the orbit and moves in the opposite direction. This effect demonstrates that Earth has a velocity relative to the stars, similar to aberration.
All of these phenomena demonstrate Earth's motion relative to other objects. It is important to note that according to the theory of relativity, we can always move to a reference frame in which the Earth is not moving--i.e., its "inertial" reference frame. So it is technically possible to define a reference frame in which the Earth does not move, while the Sun, planets, and stars orbit around the Earth, but making this reference frame consistent with our observations of Doppler shift and parallaxes would be very complicated. It is much simpler to explain our observations in a reference frame where the Earth does move, and Occam's razor directs us, as scientists, to use the simplest explanation whenever possible.
Stellar Aberration and Parallax
How do we know that Earth and other planets go around the Sun, and not the opposite?
The ancient astronomer Aristarchus thought that Earth goes around the Sun since he discovered that the Sun is much bigger than Earth. Copernicus (who is usually credited with the idea that planets go around the Sun) thought that Solar system centered on the Sun is more logical and beautiful, but had no definite proof. Kepler discovered that laws governing of orbits become much more simple if the Sun is in their center. Newton has shown that this is caused by the universal law of gravity. If gravity works, Earth and other planets have to go around the Sun, because it is much heavier.
There was no straightforward demonstration of Earth's motion until 1725 when James Bradley discovered stellar aberration. This is (apparent) yearly change in positions of all stars in the sky due to Earth's own motion. Aberration arises due to adding up of the speed of light coming from the star and Earth's own speed. This is a very complex phenomenon and its description requires some math.
Another, much simpler, consequence of Earth's motion is stellar parallax. If Earth changes its position relative to the stars, then the stars should appear to change position in the course of the year.
A common experiment illustrating parallax is just looking at a close object (a finger, a pencil etc) with one eye at the time. When you switch from one to the other eye, the object will appear to move against the background. Closer the object is to your eyes, more pronounced the effect is.
Parallax should not be confused with aberration: parallax arises from the change of Earth's position and depends on the distance to the star, while aberration is caused by Earth's great speed and does not depend on how far the star is.
Parallax of a star was first measured by Bessel in 1838. It was not measured before because this change of star's apparent position is very small (the stars are very far from us). This was a very important discovery because Aristotle himself mentioned the lack of observable stellar parallax as the proof that the Earth is not moving (he didn't have a telescope and didn't know that the stars are so distant).
A third discovery demonstrating Earth's motion was that of Doppler effect. The wavelength of the light that we receive from objects moving relative to us becomes a little shorter (i.e. bluer) when we approach the source and becomes longer (i.e. redder) when we move away from the source. When Earth moves toward a star, the star will appear slightly bluer (only high-tech instruments can measure this) while it will appear redder when Earth is on the other side of the orbit and moves in the opposite direction. This effect demonstrates that Earth has a velocity relative to the stars, similar to aberration.
All of these phenomena demonstrate Earth's motion relative to other objects. It is important to note that according to the theory of relativity, we can always move to a reference frame in which the Earth is not moving--i.e., its "inertial" reference frame. So it is technically possible to define a reference frame in which the Earth does not move, while the Sun, planets, and stars orbit around the Earth, but making this reference frame consistent with our observations of Doppler shift and parallaxes would be very complicated. It is much simpler to explain our observations in a reference frame where the Earth does move, and Occam's razor directs us, as scientists, to use the simplest explanation whenever possible.

Stellar aberration is the apparent shift of stars about their actual positions, depending on the direction Earth is moving in its orbit around the sun. It occurs because the speed of light is finite; it takes time for light to reach the observer. Stellar aberration was discovered in 1727 by James Bradley. It was the first direct proof of heliocentrism, that Earth is in orbit around the sun.
An analogy to explain stellar aberration is the apparent direction of falling rain. If rain is falling vertically, to a person running in the rain, the rain will arrive at an angle. The rain will appear to originate not from straight up but slightly tilted toward the direction the person is running.
An analogy to explain stellar aberration is the apparent direction of falling rain. If rain is falling vertically, to a person running in the rain, the rain will arrive at an angle. The rain will appear to originate not from straight up but slightly tilted toward the direction the person is running.

Stellar aberration is different from stellar parallax, which is the shift of nearby stars relative to more distant stars due to the change in Earth’s position around the sun. The magnitude of stellar parallax depends on the distance of the stars, while stellar aberration affects every star by the same maximum shift. Both phenomena are direct evidence of heliocentrism.
Stellar aberration has the same annual cycle as Earth’s orbital period. It causes stars at the ecliptic poles to move in circles, those in the ecliptic plane to move in lines, and other stars in between to move in ellipses. The maximum shift of stars due to stellar aberration is the speed of Earth’s motion around the sun divided by the speed of light, which is 0.00099365 radians or 20.49552 arcseconds.
Stellar aberration has the same annual cycle as Earth’s orbital period. It causes stars at the ecliptic poles to move in circles, those in the ecliptic plane to move in lines, and other stars in between to move in ellipses. The maximum shift of stars due to stellar aberration is the speed of Earth’s motion around the sun divided by the speed of light, which is 0.00099365 radians or 20.49552 arcseconds.

Airy’s Failure was an experiment performed in 1871 in which Sir George Biddell Airy failed to confirm the aether theory by measuring stellar aberration.
Flat-Earthers claim that the “failure” in “Airy’s Failure” is the failure of proving the motion of Earth. In reality, the experiment aimed to confirm the aether theory. The “failure” was in proving the aether theory. The experiment relied on the already accepted knowledge that Earth is in orbit around the sun.
The aether drag hypothesis predicted that a water-filled telescope should produce a different value of stellar aberration compared to an air-filled one. The change was not observed, hence the name “Airy’s failure.” The experiment helped in ruling out the aether theory.
Okay, now to the actual science, and the root of Airy’s real failure. His entire experiment was based on the false assumption that light required a medium through which to travel, commonly referred to at the time as “aether”. His experimental results were therefore skewed by that underlying false assumption, thus leading to yet another false conclusion, that the failure of starlight to act as predicted based on a heliocentric model must mean that the heliocentric model was false. In fact what his experiment really proved, which wouldn’t be scientifically explained for some time, was there was no such thing as aether and that light did NOT require a medium through which to travel.
**However, if you believe in the Aether (against all evidence), then you would conclude the Earth was stationary, even though the regular stellar aberration observations indicate that it is not stationary.
Flat-Earthers claim that the “failure” in “Airy’s Failure” is the failure of proving the motion of Earth. In reality, the experiment aimed to confirm the aether theory. The “failure” was in proving the aether theory. The experiment relied on the already accepted knowledge that Earth is in orbit around the sun.
The aether drag hypothesis predicted that a water-filled telescope should produce a different value of stellar aberration compared to an air-filled one. The change was not observed, hence the name “Airy’s failure.” The experiment helped in ruling out the aether theory.
Okay, now to the actual science, and the root of Airy’s real failure. His entire experiment was based on the false assumption that light required a medium through which to travel, commonly referred to at the time as “aether”. His experimental results were therefore skewed by that underlying false assumption, thus leading to yet another false conclusion, that the failure of starlight to act as predicted based on a heliocentric model must mean that the heliocentric model was false. In fact what his experiment really proved, which wouldn’t be scientifically explained for some time, was there was no such thing as aether and that light did NOT require a medium through which to travel.
**However, if you believe in the Aether (against all evidence), then you would conclude the Earth was stationary, even though the regular stellar aberration observations indicate that it is not stationary.
The important thing to conclude from these experiments with stellar aberration is that the ether is not dragged around the earth. If it were, the ether would be at rest with respect to the earth, the telescope would not have to be tilted and there would be no aberration at all. That is, the ether would be moving (with the earth) to the right with speed v, so there would be no need to correct for the earth's motion through the ether.


The Sagnac effect occurs to a pair of light beams traveling in a circuit in the opposite direction. If the circuit itself is rotating, then the beams will complete the circuit in different duration. The effect was first demonstrated by Georges Sagnac in 1913.
After discovering this effect, Sagnac incorrectly used the results as proof of the aether’s existence, and today’s flat-Earthers use it as “evidence” of stationary Earth. In reality, Sagnac was not aware that the effect is consistent with Einstein’s theory of relativity. And if the effect really proved aether, then optical gyroscopes are impossible.
The Sagnac effect is used as the basis of optical gyroscopes, including fiber-optic gyroscopes and ring-laser gyroscopes. In an optical gyroscope, a pair of light beams are made to travel in a circuit in the opposite direction. Because light travels at a constant speed, irrespective of the transmitter’s speed, then if the gyroscope is rotated, a beam of light will complete the circuit sooner than the other. From the difference, we can measure the rotating motion of the gyroscope.
After discovering this effect, Sagnac incorrectly used the results as proof of the aether’s existence, and today’s flat-Earthers use it as “evidence” of stationary Earth. In reality, Sagnac was not aware that the effect is consistent with Einstein’s theory of relativity. And if the effect really proved aether, then optical gyroscopes are impossible.
The Sagnac effect is used as the basis of optical gyroscopes, including fiber-optic gyroscopes and ring-laser gyroscopes. In an optical gyroscope, a pair of light beams are made to travel in a circuit in the opposite direction. Because light travels at a constant speed, irrespective of the transmitter’s speed, then if the gyroscope is rotated, a beam of light will complete the circuit sooner than the other. From the difference, we can measure the rotating motion of the gyroscope.
Did Airy prove the stars are stationary.
Michelson, Morley, Airy and even Einstein himself who at the end said "I have come to believe that the earth motion cannot be observed by any optical instruments." End quote
Michelson, Morley, Airy and even Einstein himself who at the end said "I have come to believe that the earth motion cannot be observed by any optical instruments." End quote
“While I was thinking of this problem in my student years, I came to know the strange result of Michelson’s experiment. Soon I came to the conclusion that our idea about the motion of the Earth with respect to the ether is incorrect, if we admit Michelson’s null result as a fact. This was the first path which led me to the special theory of relativity. Since then I have come to believe that the motion of the Earth cannot be detected by any optical experiment, though the Earth is revolving around the Sun.”
What Einstein meant by the “optical experiment” is the Michelson-Morley experiment. As you know, before his Theory of Relativity, scientists hypothesized the Aether theory to explain why light can propagate through space, unlike other types of waves that require a medium.
The Michelson-Morley experiment was unable to confirm the existence of Aether. They cannot find the difference of light speed traveling at different angles, even though the Earth is in motion. It is what Einstein had in mind.
I hope you are open to truth. It is not my intention to convert any flat earther to the globe, I just like to know and share truth. So I would encourage you to not share this quote out of context, now you have seen (and can research for yourself) the true origin and meaning of the full quote taken in context.
"Common sense is that layer of prejudice laid down in the mind prior to the age of eighteen."
-Albert Einstein
What Einstein meant by the “optical experiment” is the Michelson-Morley experiment. As you know, before his Theory of Relativity, scientists hypothesized the Aether theory to explain why light can propagate through space, unlike other types of waves that require a medium.
The Michelson-Morley experiment was unable to confirm the existence of Aether. They cannot find the difference of light speed traveling at different angles, even though the Earth is in motion. It is what Einstein had in mind.
I hope you are open to truth. It is not my intention to convert any flat earther to the globe, I just like to know and share truth. So I would encourage you to not share this quote out of context, now you have seen (and can research for yourself) the true origin and meaning of the full quote taken in context.
"Common sense is that layer of prejudice laid down in the mind prior to the age of eighteen."
-Albert Einstein
- A REFINEMENT OF THE MICHELSON-MORLEY EXPERIMENT
- September 1926
- Roy J. Kennedy
- https://www.pnas.org/content/12/11/621
- Direct PDF Download: A REFINEMENT OF THE MICHELSON-MORLEY EXPERIMENT
- A Repetition of the Michelson-Morley Experiment Using Kennedy’s Refinement
- November 1927
- https://journals.aps.org/pr/abstract/10.1103/PhysRev.30.692
- Direct PDF Download: A Repetition of the Michelson-Morley Experiment Using Kennedy’s Refinement
- Repetition of the Michelson-Morley Experiment
- January 1929
- A. A. M
MIICHELSON, Dr. F. G. PEASE, and F. PEARSON - https://www.nature.com/articles/123088a0
- Direct PDF Download: Repetition of the Michelson-Morley Experiment
- A Modern Michelson-Morely Experiment Using Actively Rotated Optical Resonators
- Modern Michelson-Morley experiment using cryogenic optical resonators
- February 2008
- Holger Muller, Sven Herrmann, Claus Braxmaier, Stephan Schiller, and Achim Peters
- https://arxiv.org/pdf/physics/0305117.pdf
- Direct PDF Download: Modern Michelson-Morley experiment using cryogenic optical resonators
- Laboratory Test of the Isotropy of Light Propagation at the 10−17 Level
- August 2009
- Ch. Eisele, A. Yu. Nevsky, and S. Schiller
- https://doi.org/10.1103/PhysRevLett.103.090401
The following experiments support Special Relativity and the constant speed of light. Where is your evidence for your interpretation?
Cherenkov radiation is a form of energy that we can perceive as a blue glow emitted when the electrically charged particles that compose atoms (i.e. electrons and protons) are moving at speeds faster than that of light in a specific medium.
Cherenkov radiation is a form of energy that we can perceive as a blue glow emitted when the electrically charged particles that compose atoms (i.e. electrons and protons) are moving at speeds faster than that of light in a specific medium.
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- Miller, H., P.L. Stanwix, M.E. Tobar, E. Ivanov, P. Wolf, S. Herrmann, A. Senger, E. Kovalchuk, A. Peters, “Relativity tests by complementary rotating Michelson-Morley experiments”, arXiv:0706.2031v1 [physics.class-ph].By combining results from two interferometers made of different materials, located in different hemispheres, rotating on tables, they are able to put limits on more parameters of the SME than otherwise. They have also improved both the statistics and systematic errors of the individual interferometers.
- Nguyen, H.H., “CPT results from KTeV”, (2001). arXiv:hep-ex/0112046.-
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- Lane, C.D., “Probing Lorentz violation with Doppler-shift experiments”. arXiv:hep-ph/0505130.-
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- Auerbach et al. (LSND Collaboration), “Test of Lorentz violation in Anti-νμ → Anti-νe oscillations”. Phys. Rev. D 72, 076004 (2005).These neutrino oscillations display no significant sidereal variation.Note, however, that the LSND results have been a puzzle for several years, as they appear to be inconsistent with other experiments. Just recently they were directly contradicted by the Mini-BooNE results from Fermilab (May 2007, no reference yet).
- Kosteleck and Mewes, “Lorentz violation and short-baseline neutrino experiments”, Phys. Rev. D70, 076002 (2004).Using the published results of the Liquid Scintillator Neutrino Detector (LSND) experiment, an estimated nonzero value (3 1)10−19 GeV for a combination of coefficients for Lorentz violation is obtained. This lies in the range expected for effects originating from the Planck scale in an underlying unified theory.Note, however, that the LSND results have been a puzzle for several years, as they appear to be inconsistent with other experiments. Just recently they were directly contradicted by the Mini-BooNE results from Fermilab (May 2007, no reference yet).
- Walsworth, Bear, Humphrey, Mattison, Phillips, Stoner, and Vessot, “New Clock Comparison Searches for Lorentz and CPT Violation”, arxiv:physics/0007063 (2000).Bear, D., Stoner, R.E., Walsworth, R.L., Kosteleck, V.A., and Lane, C.D., “Limit on Lorentz and CPT violation of the neutron using a two-species noble-gas maser”, Phys. Rev. Lett., 85, pg 5038–5041, (2000). arXiv:physics/0007049.Bear, D., Stoner, R.E., Walsworth, R.L., Kosteleck, V.A., and Lane, C.D., “Erratum: Limit on Lorentz and CPT Violation of the Neutron Using a Two-Species Noble-Gas Maser”, Phys. Rev. Lett., 89, 209902, (2002).Cane, Bear, Phillips, Rosen, Smallwood, Stoner, and Walsworth, “Bound on Lorentz and CPT Violating Boost Effects for the Neutron”, Phys. Rev. Lett. 93, 230801 (2004).Search for sidereal variation in the frequency difference between co-located 129Xe and 3He Zeeman masers sets the most stringent limits to date on leading order Lorentz and CPT violation. By locating the two masers in the same enclosure they eliminate many systematic errors, and are looking at variations at the level of 100 nHz (10−7 Hz !).
- Kosteleck, V.A., and Lane, C.D., “Constraints on Lorentz violation from clock-comparison experiments”, Phys. Rev. D, 60, 116010, (1999). arXiv:hep-ph/9908504.-
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- Phillips, D.F., Humphrey, M.A., Mattison, E.M., Stoner, R.E., Vessot, R.F.C., and Walsworth, R.L., “Limit on Lorentz and CPT violation of the proton using a hydrogen maser”, Phys. Rev. D, 63, 111101, (2001). arXiv:physics/0008230.Humphrey et al., “Testing CPT and Lorentz Symmetry with Hydrogen Masers”, Phys. Rev. A68, 063807 (2003). arXiv:physics/0103068.-
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- Biller, S.D., Breslin, A.C., Buckley, J., Catanese, M., Carson, M., Carter-Lewis, D.A., Cawley, M.F., Fegan, D.J., Finley, J.P., Gaidos, J.A., Hillas, A.M., Krennrich, F., Lamb, R.C., Lessard, R., Masterson, C., McEnery, J.E., McKernan, B., Moriarty, P., Quinn, J., Rose, H.J., Samuelson, F., Sembroski, G., Skelton, P., and Weekes, T.C., “Limits to quantum gravity effects from observations of TeV flares in active galaxies”, Phys. Rev. Lett., 83, 2108–2111, (1999). arXiv:gr-qc/9810044.-
- Boggs, S.E., Wunderer, C.B., Hurley, K., and Coburn, W., “Testing Lorentz Non-Invariance with GRB021206”, (2003). arXiv:astro-ph/0310307.-
- Ellis et al., “Robust Limits on Lorentz Violation from Gamma-Ray Bursts”, arXiv:astro-ph/0510172 (2005).If the speed of light has an energy dependence c(E) ~ c0(1 − E/M), a limit on M is obtained: M > 0.91016 GeV/c2.
- Kosteleck and Mewes, “Cosmological Constraints on Lorentz Violation in Electrodynamics”, Phys. Rev. Lett., 87, no. 25, 251304 (2001).Certain coefficients for Lorentz violation are bounded to less than 310−32.
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- Greisen, K., “End to the cosmic ray spectrum?”, Phys. Rev. Lett., 16, pg 748–750, (1966).Zatsepin, G.T., and Kuzmin, V.A., “Upper limit of the spectrum of cosmic rays”, J. Exp. Theor. Phys. Lett., 4, pg 78–80, (1966).The original GZT papers.