# Time dialation

## Main Question or Discussion Point

time dialation is a function of only velocity ie if you are travelling @ C in any direction time stops yes? Time dialation is not dependent on any other parameter other than velocity?

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JesseM
Time dilation in any given inertial frame is only a function of the clock's velocity in that frame, yes (which means different frames disagree on the rate the same clock is ticking, since they disagree on its velocity). In any inertial frame, a clock moving at velocity v will be slowed down by a factor of $$\sqrt{1 - v^2/c^2}$$. Note, however, that it's impossible for any massive object (like a clock) to move at exactly c, since it would take an infinite amount of energy to accelerate them to that speed; only massless particles like photons can move at exactly c.