View Single Post
robphy
#5
Feb23-12, 08:40 PM
Sci Advisor
HW Helper
PF Gold
robphy's Avatar
P: 4,137
A timelike curve in spacetime is a curve whose tangent vector at each event is timelike [in the tangent vector space associated with that event], as the stated in the original post.

It seems that there is an implicit assumption that the curves under discussion here have tangent vectors that don't change their type or temporal orientation.