# Measure this!!!

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How do you measure a distance between two points, if one of them is static (has 0 velocity relative to you), and the other one moves with near c velocity relative to you? Is there length conraction in this case?

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How do you measure a distance between two points, if one of them is static (has 0 velocity relative to you), and the other one moves with near c velocity relative to you? Is there length conraction in this case?

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There is no length contraction in this case.

This is because length contraction only occurs if the observed length of the system you are measuring is moving as a whole respective to the stationary observer. In your scenario, the measured length of the two points are not moving together with respect to the stationary observer, and hence no length contraction results as oberved by the stionary observer.

Quote me if I m wrong.

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There is no length contraction in this case.

This is because length contraction only occurs if the observed length of the system you are measuring is moving as a whole respective to the stationary observer. In your scenario, the measured length of the two points are not moving together with respect to the stationary observer, and hence no length contraction results as oberved by the stionary observer.

Quote me if I m wrong.

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lenght contarction refers to solid objects, so no we wouldn't call this lenght contraction. Of course the distance between the two points does vary from frame to frame like the length of a rod.

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lenght contarction refers to solid objects, so no we wouldn't call this lenght contraction. Of course the distance between the two points does vary from frame to frame like the length of a rod.

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Quote me if I m wrong.

Ok, i'll quote you, but i dont know if u are wrong.

thats why I'm asking. Here's my dilemma more concretely.

Let's say something (point A) travels with near c velocity relative to your position. When it gets to point B (which stands still relative to your position, namely C), you measure the distance, from C to B, and you measure 10km, for example.

But if observing the event with frame of reference in point A (the traveling object), and if you measure the distance between B and C, when point A overlaps with B (thus actually measuring A to C distance), then there's length contraction, and you get, say 6km.

And both frames have to be equally valid under Einsteins postulates. In this case they dont seem to me they are.

What I'm asking is which is the right way to measure the distance between two points, of which one is traveling with near c velocity.

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Quote me if I m wrong.

Ok, i'll quote you, but i dont know if u are wrong.

thats why I'm asking. Here's my dilemma more concretely.

Let's say something (point A) travels with near c velocity relative to your position. When it gets to point B (which stands still relative to your position, namely C), you measure the distance, from C to B, and you measure 10km, for example.

But if observing the event with frame of reference in point A (the traveling object), and if you measure the distance between B and C, when point A overlaps with B (thus actually measuring A to C distance), then there's length contraction, and you get, say 6km.

And both frames have to be equally valid under Einsteins postulates. In this case they dont seem to me they are.

What I'm asking is which is the right way to measure the distance between two points, of which one is traveling with near c velocity.

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if they are points, there is no contraction, for there are no dimensions to contract. i was under the impression that the contraction was done by the object and not the space between two objects.

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if they are points, there is no contraction, for there are no dimensions to contract. i was under the impression that the contraction was done by the object and not the space between two objects.

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How do you measure a distance between two points, if one of them is static (has 0 velocity relative to you), and the other one moves with near c velocity relative to you? Is there length conraction in this case?

stop time for a moment...

I believe Einstein came up for an equation for that:

-------let's say that the static object (s) let out a light beam towards the moving object. When the static object recieves the light beam after it has reflected off the moving object then:

<<<<<<<<(s, recieves light again) - (time s sent light beam)

<<<<<<<<<<<<<<<<<<<<<<<<2

is this what you are asking?

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