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Einstein states that a moving object's shape changes due to the length contraction. But people had done such an experiment: Taking photos to a moving object, but they didn't find Lorentz contraction, instead, the object on picture just takes a rotation, which is the aberration. I'm confused about the two effect. Is there self-contradiction?


marked as duplicate by John Rennie, Stan Liou, Kyle Kanos, Brandon Enright, Qmechanic Mar 7 '14 at 21:28

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The Lorentz transformation gives the relationship between the time and space coordinates of two inertial reference frames in relative motion.

As such, it is coordinate length contraction and coordinate time dilation that results.

Thus, in SR, observing (or measuring) length contraction does not mean to photograph length contraction. Rather, it means recording events: "the front of the rod was at this location at the same (coordinate) time as the rear of the rod was at this other location; the rod's (coordinate) length is thus..."

From the article "Photography in Special Relativity":

Observation vs Photography

In Special Relativity there is a very specific meaning to the word observer. An observer is one of an infinite collection, in space and time, of robots whose sole task in life is to record the time and location of each detected event. When we say that an observation was made we simply mean that the space and time coordinates of an event have been recorded.

A photograph is a record of all of the photons that were received at the focal point of the camera at the time the photograph was taken.

These are fundamentally different processes and they give us very different information about the universe.


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