# Higgs field and the null geodesic

How does coupling to the Higgs field take a particle with a spacetime interval of zero and give it a non-zero value, i.e, how does it move it off the null geodesic? [of course, the Higgs field is responsible for a fundamental particle's rest mass, assuming a non-zero coupling constant, and such particles are confined to time-like intervals, okay, but why?]

• @HarryMcLaughlin Just a small correction: the Higgs field did not have zero vacuum expectation value for a few minutes. It took only $10^{-12}$ second (en.wikipedia.org/wiki/Electroweak_epoch). – mpv Nov 27 '14 at 16:43