I'm coming across a contradiction that I can't resolve. Two points on the ground are separated by 30km. If you're in a moving frame at velocity +v relative to the ground and you view those two points on the ground, would those two points be greater or less than 30km apart? At first, I thought it would be less, since the proper length is 30km and the ground is moving at a velocity -v relative to you. So the separation would be Lo/lorentzfactor and thus be contracted. But when I saw the solutions and they used the lorentz transformations, the solutions yielded a result greater than 30km. The solutions make actually sense, but I couldn't resolve my original method and the method used in the solutions. Can anyone tell me what is wrong with my original approach? It's problem 2a on the link below. Thanks!(adsbygoogle = window.adsbygoogle || []).push({});

https://tbp.berkeley.edu/exams/459/download/ Problem 2a

https://tbp.berkeley.edu/exams/536/download/ the solutions

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# I Length contraction vs expansion

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