Throughout our relativity section in class, we've had two problems with light and a train, and I'm confused as to why they are two different answers.(adsbygoogle = window.adsbygoogle || []).push({});

The first is that Mavis is on a train moving close to the speed of light, and lightning bolts hit the left (back) and right (front) part of the train. Mavis thinks the right one struck first since she is moving toward that part, since the train is moving with her in it, so the wave front of that one reached her before the other one.

Now, another problem says that two lights shoot in from the middle of the train (distance of train divided by 2), one goes straight left, hitting left wall and one goes straight right, hitting right wall. Again, the train is going close to the speed of light. However, the answer for this one is that in Mavis's perspective, she sees the light reaching both walls at the same time, because she is in rest frame, because to her, the cart isn't moving.

Well, to her, the cart isn't moving in the first problem either, right? So how come she has different perspectives in the two scenarios?

I'd appreciate an explanation, thank you!

(It's not a homework problem but just me asking a question about a concept, so I hope this is the right category.)

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# Relativity: light in train with person in it

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