Determined c in S v. Result of the Michelson_Morley Exp.

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Discussion Overview

The discussion revolves around the implications of the Michelson-Morley experiment in relation to the behavior of light in moving reference frames. Participants explore the derivation of light paths in both stationary and moving systems, examining the velocities involved and the resulting time calculations. The scope includes theoretical reasoning and mathematical derivations related to the experiment.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant outlines a 23-point derivation involving light paths in moving and stationary systems, asserting that the light emitted by the moving system S' moves with velocity c in the stationary system S.
  • Another participant emphasizes that light is a wave and discusses the historical context of the aether, suggesting that the Michelson-Morley experiment failed to detect the velocity of the medium through which light propagates.
  • Some participants propose that the ray of light emitted from the moving system S' towards the y-axis moves with velocity sqrt(c^2 + v^2), aiming to reconcile time measurements with the results of the Michelson-Morley experiment.
  • There is a suggestion that the time taken for light to travel in the stationary system S should equal the time derived from the experiment, indicating a potential inconsistency in the assumptions made about light's behavior.

Areas of Agreement / Disagreement

Participants express differing views on the implications of the Michelson-Morley experiment and the behavior of light in moving reference frames. There is no consensus on the correctness of the proposed velocities or the interpretations of the experiment's results.

Contextual Notes

Some assumptions regarding the nature of light and the definitions of velocities in different frames remain unresolved. The discussion reflects ongoing debates about the interpretation of experimental results and the theoretical frameworks applied.

arbol
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1. Let S' be an x'y'-coordinate system. Let the x'-axis of S' coincide with the x-axis of an xy-coordinate system S. Let the y'-axis of S' be parallel to the y-axis of S. Let S' move in system S along the x-axis of S with constant velocity v in the direction of increasing x, and let the origin of S' coincide with the origin of S at the time t = t' = 0s.

2. Let a ray of light emitted by the moving system S' depart from x' = 0m at the time t' = 0s towards x' = x'1 and reach x'1 at the time t' = t'1, and let it be reflected at x'1 back to x' = 0m, reaching 0m at the time t' = 2*t'1.

3. Let the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 be, in the moving system S', the length L of a rigid rod.

4. Let a ray of light emitted by the moving system S' depart from y' = 0m at the time t' = 0s towards y' = y'1 and reach y'1 at the time t' = t'1, and let it be reflected at y'1 back to y' = 0m, reaching 0m at the time t' = 2*t'1.

5. Let the length of the path of the ray of light emitted by the moving system S' from y' = 0m to y' = y'1 be also (independently), in the moving system S', the length L of the rigid rod.

6. Let a ray of light emitted by the stationary system S depart from x = 0m at the time t = 0s towards x = x1 and reach x1 at the time t = t1, and let it be reflected at x1 back to x = 0m, reaching 0m at the time t = 2*t1.

7. Let the length of the path of the ray of light emitted by the stationary system S from x = 0m to x = x1 be also (independently), in the stationary system S, the length L of the rigid rod.


8. Let a ray of light emitted by the stationary system S depart from y = 0m at the time t = 0s towards y = y1 and reach y1 at the time t = t1, and let it be reflected at y1 back to y = 0m, reaching 0m at the time t = 2*t1.

9. Let the length of the path of the ray of light emitted by the stationary system S from y = 0m to y = y1 be also (independently), in the stationary system S, the length L of the rigid rod.

10. Let the time (t'1 - 0s) = (t1 - 0s) = L/c.

11. Let the Length of the path of the moving system S' from x = 0m to x = v*L/c be, in the stationary system S, the length D of a rigid rod.

12. In the moving system S', the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m is

2*L.

13. In the moving system S', the length of the path of the ray of light emitted by the moving system S' from y' = 0m to y' = y'1 and back to y' = 0m is

2*L.

14. In the stationary system S, the length of the path of the ray of light emitted by the stationary system S from x = 0m to x = x1 and back to x = 0m is

2*L.

15. In the stationary system S, the length of the path of the ray of light emitted by the stationary system S from y = 0m to y = y1 and back to y = 0m is

2*L.

16. In the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m is

D + L + D + (L - 2*D) = 2*L.

17. In the stationary system S, the length of the path of the ray of light emitted by the moving system S' from y' = 0m to y' = y'1 and back to y' = 0m is

sqrt(L^2 + D^2) + sqrt (L^2 + D^2) = 2*sqrt(L^2 + D^2).

18. The ray of light emitted by the moving system S' moves in the stationary system S with the determined velocity c.

19. The time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1 and back to x' = 0m is

2*L/c.

20. The time in the stationary system S the ray of light emitted by the moving system S' takes to move from y' = 0m to y' = y'1 and back to y' = 0m is

2*sqrt(L^2 + D^2)/c.

21. By the result of the Michelson-Morley Experiment,

2*L/c = 2*sqrt(L^2 + D^2)/c, or

L = L*sqrt(1 + (D/L)^2).

22. The problem with the result of the Michelson-Morley experiment is that (1) L in both sides of the equation "L = L*sqrt(1 + (D/L)^2)" is the length of the rigid rod in the stationary system S, and (2) the ray of light emitted by the moving system S' moves in the stationary system S with the determined velocity c.

23. The problem with the ray of light emitted by the moving system S' moving in the stationary system S with the determined velocity c is that (1) L in both sides of the equation "L = L*sqrt(1 + (D/L)^2)" is the length of the rigid rod in the stationary system S, and (2) the equation "L = L*sqrt(1 + (D/L)^2)" is the result of the Michelson-Morley experiment.
 
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Hi arbol,

I am not going to go through each step in a 23-point derivation. Let me just say that you are correct that the emitter is moving at the same velocity as the detector in any frame.

However, remember that light (especially in this experiment) is a wave. Most waves that had been studied up until the M&M experiment propagated through a medium. If you were to build a similar apparatus for acoustical waves you could use it to detect the motion of the medium wrt your device. This is the velocity the the M&M experiment surprisingly failed to detect: the velocity of the medium through which light propagates, aka the aether.
 
DaleSpam said:
Hi arbol,

I am not going to go through each step in a 23-point derivation. Let me just say that you are correct that the emitter is moving at the same velocity as the detector in any frame.

However, remember that light (especially in this experiment) is a wave. Most waves that had been studied up until the M&M experiment propagated through a medium. If you were to build a similar apparatus for acoustical waves you could use it to detect the motion of the medium wrt your device. This is the velocity the the M&M experiment surprisingly failed to detect: the velocity of the medium through which light propagates, aka the aether.


I was going to suggest the following:

I propose (1) that in the stationary system S, the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 moves with the determined velocity c and (2) that in the stationary system S, the ray of light emitted by the moving system S' from y' = 0m to y' = y'1 moves with velocity sqrt(c^2 + v^2).

The purpose for my proposition (if it has not been proposed already) is to have

(1) The time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1 and back to x' = 0m be

2*L/c, and

(2) The time in the stationary system S the ray of light emitted by the moving system S' takes to move from y' = 0m to y' = y'1 and back to y' = 0m be

2*sqrt(L^2 + D^2)/sqrt(c^2 + c^2) = 2L/c = 2*t'1 (the result of the Michelson-Morley experiment).
 
arbol said:
I was going to suggest the following:

I propose (1) that in the stationary system S, the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 moves with the determined velocity c and (2) that in the stationary system S, the ray of light emitted by the moving system S' from y' = 0m to y' = y'1 moves with velocity sqrt(c^2 + v^2).

The purpose for my proposition (if it has not been proposed already) is to have

(1) The time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1 and back to x' = 0m be

2*L/c, and

(2) The time in the stationary system S the ray of light emitted by the moving system S' takes to move from y' = 0m to y' = y'1 and back to y' = 0m be

2*sqrt(L^2 + D^2)/sqrt(c^2 + c^2) = 2L/c = 2*t'1 (the result of the Michelson-Morley experiment).


I think the following is a more appropriate and a more comprehensive proposition:

I propose (1) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 is

L + D, then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1
to be

(L + D)/(c + v), and

the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 to move in the stationary system S with velocity (c + v),

(2) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = x'1 back to x' = 0m is

L - D, then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = x'1 back to x' = 0m
to be

(L - D)/(c - v), and

the ray of light emitted by the moving system S' from x' = x'1 back to x' = 0m to move in the stationary system S with velocity (c - v),


(3) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m is

2*L, then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1
and back to x' = 0m to be

2*L/c, and

the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m to move in the stationary system S with velocity c,

(4) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m is

2*t'1*(c^2 - v^2), then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1
and back to x' = 0m to be

2*t'1*(c^2 - v^2)/(c^2 - v^2), and

the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m to move in the stationary system S with velocity (c^2 - v^2), and

(5) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' (1) from y' = 0m to y' = y'1 or (2) from y' = y'1 back to y' = 0m is

sqrt(L^2 + D^2), and

the length of the path of the ray of light emitted by the moving system S' from y' = 0m to y' = y'1 and back to y' = 0m is

2*sqrt(L^2 + D^2), then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move (1) from y' = 0m to y' = y'1, (2) from y' = y'1 back to y' = 0m, or (3) from y' = 0m to y' = y'1 and back to y' = 0m to be

sqrt(L^2 + D^2)/sqrt(c^2 + v^2), sqrt(L^2 + D^2)/sqrt(c^2 + v^2), or 2*sqrt(L^2 + D^2)/sqrt(c^2 + v^2) respectively, and

the ray of light emitted by the moving system S' (1) from y' = 0m to y' = y'1, (2) from y' = y'1 back to y' = 0m, or (3) from y' = 0m to y' = y'1 and back to y' = 0m to move in the stationary system S with velocity sqrt(c^2 + v^2),
 
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arbol said:
(4) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m is

2*t'1*(c^2 - v^2), then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1
and back to x' = 0m to be

2*t'1*(c^2 - v^2)/(c^2 - v^2), and

the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m to move in the stationary system S with velocity (c^2 - v^2),

This part ought to be written as

(4) that if in the stationary system S, the length of the path of the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m is

t'1*(c^2 - v^2), then


the time in the stationary system S the ray of light emitted by the moving system S' takes to move from x' = 0m to x' = x'1
and back to x' = 0m to be

t'1*(c^2 - v^2)/(c^2 - v^2), and

the ray of light emitted by the moving system S' from x' = 0m to x' = x'1 and back to x' = 0m to move in the stationary system S with velocity (c^2 - v^2),
 

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