Applet about special relativity

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SUMMARY

The discussion focuses on the applet illustrating special relativity, specifically the behavior of clocks in a moving frame. Participants analyze why the front and rear clocks of a light clock do not display the same time when observed from a moving frame. The consensus identifies that the correct explanation is that the clocks, although starting simultaneously in a stationary frame, do not remain synchronized when in motion due to the effects of time dilation and the relative motion of the observer. The conclusion emphasizes that the front clock does not start at zero from the moving observer's perspective due to the differing distances the light signals must travel.

PREREQUISITES
  • Understanding of special relativity principles
  • Familiarity with the concept of time dilation
  • Knowledge of inertial frames of reference
  • Basic comprehension of light propagation in physics
NEXT STEPS
  • Explore the implications of time dilation in special relativity
  • Study the concept of simultaneity in different inertial frames
  • Investigate the Lorentz transformations and their applications
  • Learn about the twin paradox and its relation to time dilation
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Students of physics, educators teaching special relativity, and anyone interested in understanding the nuances of time and motion in relativistic contexts.

Niles
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Homework Statement


http://mp.pearsoncmg.com/probhtml/applets/Relat_L.html

In the above applet, the clocks at the front and rear mirrors of the light clock do not show the same time when viewed from the moving frame.

Why is that? The clocks move with the same speed (same system of inertia), so I believe the reason why is that the signal takes a longer time to reacha stationary observer - but this answer was wrong.
 
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The other two possible answers are

1) The clock in the front is farther away from the clock in the back, so it must experience a greater time delation.

- I believe not, since they are both moving with the same speed - same system of inertia.

2) Since both clocks start at same time when in rest, they cannot start at same time when moving.

- I believe not (although the correct answer is either 1 or 2), because again - same inertial system, so why would they have to differ?
 
If you're in the moving frame (e.g. if you're at the center of the bottom blue bar, moving along with the system, the clocks will be the same (for all purposes, it will be like you are in the top situation).

But if you are in the top situation and you see the bottom clock pass by, then they will show different times. The reason is exactly the one depicted in the applet: the light beam has to travel farther to overtake the mirror moving away, and when it is reflected it will have to travel less than l because the other mirror is moving toward it.

This all makes perfect sense to me (at least, presented this way): longer path = longer time.
So what exactly is the question ?
 
The exact question is, why the front clock is not starting at 0.
 
We are vieweing them fron the moving frame.

The correct answer is 2 - why is that?!
 

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