How to correctly mark event B on the picture?

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    Clock Photon Velocity
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Discussion Overview

The discussion revolves around the correct identification and marking of event B in a scenario involving a photon clock moving at velocity V. Participants explore the implications of the Principle of Relativity on the positioning of events A and B in two different frames of reference, one where the clock is moving and another where it is at rest.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant describes a photon clock moving to the right and seeks to identify event B in a second frame where the clock is at rest.
  • Another participant suggests that event B in the lower image is located at the middle of the left-bottom mirror where it meets the arrow, interpreting the frames as different perspectives of the same events.
  • Several participants express uncertainty about the clarity of the experiment's description and question the movement of the clock in the second image, suggesting that it may not gain anything by moving left.
  • There is a mention of an extra quantity ##t_0## in the second diagram, with questions about its relevance and the meaning of the shading of the mirrors.
  • One participant asserts that in the second picture, there is no velocity and no moving clock, stating that event A occurs directly above event B.
  • Another participant reiterates the relationship between the two frames using a mathematical expression, indicating a reversible relationship between the frames.

Areas of Agreement / Disagreement

Participants express differing views on the movement of the clock in the second frame and the implications for marking event B. There is no consensus on the correct identification of event B or the clarity of the experiment's setup.

Contextual Notes

Participants highlight limitations in the description of the experiment, including assumptions about the movement of the clock and the significance of the variables used. The discussion remains open-ended regarding the definitions and implications of events A and B.

Mike_bb
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Hello!

I have photon clock that moves to right side with velocity V.
In the first case events A and B are depicted on the picture on the top side:

1.jpg


In accordance with the Principle of Relativity I obtained second case.
But I can't mark event B in the second case on the bottom side. Where is event B located in this case?

Thanks!
 
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I guess you describe the same events A and B from the viewpoint of two different frames: In the first frame (upper image), the light clock moves to the right, in the second frame (lower image) it moves to the left. If that's the case, then event B on the lower image is located in the middle of the left-bottom mirror where it meets the arrow.
 
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It's difficult to know because you haven't described the experiment clearly. @Histspec's guess is reasonable and may be correct, but it's a guess.

You say the clock is moving to the right. Presumably that's in the top picture. Is it supposed to be moving to the left in the lower picture? That's what I would guess, but that's an unusual thing to do with a light clock since it doesn't really gain you anything. What's the extra quantity ##t_0## in the srcond diagram? How does it relate to anything else? Is the shading of the mirrors meant to be indicative of something? And what are events A and B supposed to be?

In particular, if you write down a description of A and B I suspect you will answer your own question.
 
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Ibix said:
It's difficult to know because you haven't described the experiment clearly. @Histspec's guess is reasonable and may be correct, but it's a guess.

You say the clock is moving to the right. Presumably that's in the top picture. Is it supposed to be moving to the left in the lower picture? That's what I would guess, but that's an unusual thing to do with a light clock since it doesn't really gain you anything. What's the extra quantity ##t_0## in the srcond diagram? How does it relate to anything else? Is the shading of the mirrors meant to be indicative of something? And what are events A and B supposed to be?

In particular, if you write down a description of A and B I suspect you will answer your own question.
In the top picture clock is moving to right. But in the lower picture clock is rest. (In accordance with Principle of Relativity)

$$c^2\Delta t^2-\Delta x^2 = c^2\Delta t_0^2-\Delta x'^2$$
 
Mike_bb said:
In the top picture clock is moving to right. But in the lower picture clock is rest.
Then, in the second picture there is no velocity ##v## and no moving clock. Event A occurs directly above event B.
 
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PeroK said:
Then, in the second picture there is no velocity ##v## and no moving clock. Event A occurs directly above event B.
These equality for first and second picture:

$$c^2\Delta t^2-\Delta x^2 = c^2\Delta t_0^2-\Delta x'^2$$
$$c^2\Delta t_0^2-\Delta x'^2 = c^2\Delta t^2-\Delta x^2$$

In accordance with Principle of Relativity we have that first frame and second frame are reversable. It's shown on the first and second picture.
 
PeroK said:
Event A occurs directly above event B.
Thanks. It's right!
 

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