A long spaceship with a clock C1 at the front and a clock C2 at the rear is moving at a uniform velocity wrt to earth after being launched from the earth. Its motion wrt to earth is tangent to a radial vector perpendicular to the earths surface. We now synchronize C! and C2 by finding the midpoint P of the spaceship and from P we emit a light flash. When the flash reaches C1 we set it to zero and when it reaches C2 we set it to zero - since the distance from P to C1 is the same as the distance from P to C2, the two clocks are now synchronized in the moving frame of the spaceship.(adsbygoogle = window.adsbygoogle || []).push({});

We next rotate the spaceship 180 degrees so that C1 is at the rear and C2 is at the front - we can do this ether by rotating the entire vehicle, or by exchanging them along a linear line, or by initally having placed them on a turntable - we again send a flash from the midpoint P and discover that it arrives at C1 before C2.

By measuring the amount of de-synchronization, we calculate the velocity of the spaceship wrt to space!:

Somethings obviously wrong - but what

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# Detecting Motion Paradox

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