To solve one of my textbook problems about uncertainty principle in relativistic case, I found that for every individual measured momentum p, I needed to assume [tex]p < \gamma mc[/tex] to get the correct answer, where [tex]\gamma = \frac{1}{{\sqrt {1 - \frac{{{v^2}}}{{{c^2}}}} }}[/tex].(adsbygoogle = window.adsbygoogle || []).push({});

But I keep suspecting whether the assumption is valid,because I have a vague memory that I heard that a particle can exceed the speed limit c when considering uncertainty principle. Then why can't the momentum exceed this limit?

Are these information enough for you guys? Or do I need to stick my textbook problem in this post?

Actually I was originally going to title this post as Uncertainty principle and FTL, but what I am going to ask is not that fancy so I change the title. :)

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# Uncertainty principle and limit of momentum.

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