Recent content by Junjie

I am a bit confused at "orthonormal tetrad" in General Relativity... I think orthonormal tetrad should be a set of vectors like [FONT="Georgia"]e0= (1,0,0,0) e1= (0,1,0,0) e2= (0,0,1,0) e3= (0,0,0,1) However, in my book, it is written as [FONT="Georgia"]e0= (-1,0,0,0) e1=...