Einstein wrote about a long train that experienced bolts of lighting hitting on both ends. Einstein tells us that a midway observer on the ground would see both bolts at the same time, but the midway observer on the train would have moved off from the same ground point because of the time it takes the flash to travel.(adsbygoogle = window.adsbygoogle || []).push({});

Now if you look at this problem using the Lorentz transform, it is not true that momentum of the train is important to the Galilean observer aboard the train, writing for the transform C+V and C-V?

This problem would not occur for the ground observer, but there is still the question if the bolts came straight down on both ends of the train, how does the bolt now instantly travel at right angles to the ground to meet at the midpoint of the tracks?

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# Question about Einstein's train and lightning

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