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by emptybits
3046 days ago
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My first reaction to what you said was "bah, the scale of space and time in which railways operate wouldn't be impacted by Einstein's ideas about space and time." (And they aren't, in a practical sense.) But then I Googled up this short interview with Galison.[1] Suppose, Einstein reasoned, that you wanted to know what time a train arrived in a train station. Easy enough: you see where the hand of your watch is at the time the engine pulls up alongside you. But what if you wanted to know when a train was pulling into a distant station? How do you know whether an event here is simultaneous with an event there? Einstein insisted that we need a simultaneity - fixing procedure, a definite system of exchanging signals between the stations that would take into account the time it took for the signal to get from one station to another. By pursuing this insight, Einstein discovered that two events that were simultaneous in one frame of reference would not be simultaneous in another. Moreover, since a length measurement involves determining the position of the front and back of an object at the same time, the relativity of simultaneity meant that length was relative as well. By removing the absolutes of space and time, Einstein restructured modern physics. OP is marginally clever parody but your comment led me to this. So thanks! [1] https://history.aip.org/exhibits/einstein/essay-einsteins-ti... |
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