Hi all, I'm currently a stage 1 Physics student at uni; and in the process of learning Special Relativity.(adsbygoogle = window.adsbygoogle || []).push({});

I was reading my textbook and came across this in the Time and Space section:

Suppose an observer in frame S measures two flashbulbs going off at the same time t but at different x-coordinates x1 and x2. Then an observer in frame S` would measure the time interval t`1 - t`2 between the flashbulbs going to be:

t`1 - t`2 = [itex]\gamma[/itex]((x2-x1)*(u/c)^2)

I was wondering why it's t`1 - t`2 instead of the usual t`2 - t`1. I assume it's to prevent the final answer being negative? I feel like I'm being stupid asking this :|

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# Help understanding a SR equation!

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