Q:

if speed of light is constant and time dilated when object is moving, so when object is moving at 1/2 of the speed of light, the time should dilate to half of regular time, but according to the equation given by special relativity, it's not, why?

- larry (age 50)

Ramsey, nj

- larry (age 50)

Ramsey, nj

A:

Hello Larry,

I'm not sure what makes you say that for the object "moving at 1/2 of the speed of light, the time should dilate to half of regular time". As you already mentioned, according to Special Relativity, the time dilation factor at 0.5c is sqrt(1-v^{2}/c^{2}). At v=0.5c, factor is sqrt(3)/2, not 1/2.

Hope this answers your question.

Lingyi

p.s. Note that neither frame is more "regular" than the other. We say that events on the "moving" object take longer than the observer on that object says. When they look back at us, they say we're "moving" and that events on earth take longer than what we say. /mw

*(published on 01/24/2013)*