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Q & A: time dilation

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Most recent answer: 05/15/2011
Q:
Suppose one particle of an entangled pair were placed on a spaceship traveling near the speed of light. The other particle is left on Earth and caused to change states once every second in the Earth frame of reference. How often would the particle change states in the spaceship frame of reference? Or how often would an observer in the spaceship frame of reference perceive the state to change?
- Joshua York (age 35)
Fullerton, CA, USA
A:
We can't give you an exact number, because you didn't specify the exact fraction of c that the spaceship was traveling. However, from the point of view of the spaceship, the light is "changing state" (not sure what that means) less often than once a second. The beauty of relativity is that I don't have to know what "changing state" means, since all clock-like rates transform exactly the same way.

And yes, if something like that is also going on on the spaceship, from the earth point of view, it's also happening less often than once per second.

Probably the next phase of this question will be some follow-up about entanglement, since so far you've introduced that but not used it. Just a preview- tests of the Bell Inequality violations using various detectors in relative motion have already been done.

Mike W.

(published on 05/15/2011)

Follow-up on this answer.