Error in special relativity Albert Einstein assumed

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Discussion Overview

The discussion revolves around the interpretation of light behavior in the context of special relativity, particularly focusing on the scenario of a moving boxcar with an observer inside it. Participants explore the implications of time dilation and the path of light as perceived by different observers, addressing both theoretical and conceptual aspects of the problem.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant argues that the light pulse, as perceived by observer 1 in the boxcar, travels vertically and returns to its original position, while observer 2 sees it traveling a longer diagonal path due to the boxcar's motion.
  • Another participant questions the assumption that the light does not return to observer 1, suggesting that from observer 1's perspective, the light moves straight up and down regardless of the boxcar's motion.
  • A different viewpoint emphasizes that the description of events must include the same occurrences from both observers' perspectives, noting that the vertical component of light's velocity appears different to observer 2.
  • Some participants assert that the motion of the boxcar does not affect the vertical path of the light, maintaining that the speed of light remains constant at c for both observers.
  • One participant challenges the idea that light particles gain horizontal velocity relative to the boxcar, questioning the implications of such a scenario on the principles of relativity.
  • Another participant notes that if one assumes a preferred reference frame, it contradicts the postulate of relativity that states the laws of physics are the same in all inertial frames.
  • Several participants reiterate that the velocity of light is constant, but its directional velocity is affected by the motion of the emitter, leading to different observations in different frames.

Areas of Agreement / Disagreement

Participants express differing views on how light behaves in a moving frame, with no consensus reached on the implications of the boxcar's motion on the light's path or the validity of the assumptions made about observer perspectives.

Contextual Notes

There are unresolved assumptions regarding the nature of light's path and the implications of the boxcar's motion on the perception of light by different observers. The discussion highlights the complexity of interpreting events in special relativity without reaching definitive conclusions.

  • #31


Tuomaaca said:
I think i understand your question. Correct me if I'm wrong, but here's what I'm getting:

The observer emits a "pulse of light" from his flashlight to the center of the mirror ("straight upward"). The light goes up. Since the mirror is moving with a velocity (let's say v), the light pulse should hit at a spot vt away from (or "behind") the center of the mirror, where t is the time it takes for light to travel from floor to ceiling.

But, a contradiction! According to Observer 1 (who is moving with a constant velocity so that he can't even tell that he's moving), he emitted a pulse "straight up" and it should also come "straight down," right back at his flashlight.
no i don't agree ..
here what is wrong and i said about 200 times but seems everybody ignore it YOU said:
he emitted a pulse "straight up" and it should also come "straight down," right back at his flashlight.
yes it will come straight down but not back to his flashlight
this observer emitted a flashlight straight upward moving with velocity C
observer 1 is in the train.
observer 2 is outside.
[PLAIN]http://img686.imageshack.us/img686/8618/imgwkv.jpg
 
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  • #32


yeah another way of explaining it(AFTER READING ABOVE POST):
if u say that according to observer1 the mirror is not moving away from him and so is the light
he sees the light moving upward in c and downward again and that what really happens as he can't see that light returned to flash light while it didn't
but since the frame was moving with velocity vtrain then light should be moving upward with velocity c and moving diagonally with velocity v train and that s impossible
 
  • #33


If the pulse of light is aimed vertically in the frame where the flashlight is moving to the right then it is aimed to the left in the frame where the flashlight is stationary. You cannot have it be vertical in both frames.
 
  • #34


thetrice said:
yeah another way of explaining it(AFTER READING ABOVE POST):
if u say that according to observer1 the mirror is not moving away from him and so is the light
he sees the light moving upward in c and downward again and that what really happens as he can't see that light returned to flash light while it didn't
but since the frame was moving with velocity vtrain then light should be moving upward with velocity c and moving diagonally with velocity v train and that s impossible

Observer1 sees the light moving straight up and down with speed "c".
Observer2 sees the light "aberrated", i.e. moving at an angle in the direction of vtrain. Light in the frame of Observer2 moves at "c" just the same.
 
  • #35


thetrice said:
no i don't agree ..
here what is wrong and i said about 200 times but seems everybody ignore it

No, you are either ignoring or misunderstanding what everybody else has said in this thread. I don't see any sign that either "side" is going to budge in this discussion, so there's no point in continuing it.
 

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