January 24, 2008

East Coast Relativity keeps it real

I learned today that the widely used metric signatures in general relativity are referred to as East coast and West coast. Somehow, I have been through 2 GR courses and a ton of cosmology without ever seeing this. A spacetime interval dS2 = -c2 dt2 + dx2 + dy2 + dz2, is Eastern while (+---) on the right side would be Western.

So in keeping with my general ambivalence towards other parts of the country, I am happy to find out that my choice of coast also suits my choice of metric convention. Still, it's no wonder physicists are always shooting each other.


Doug said...

I've also seen it given as a HEP / GR difference, with GR being East. We like our space-like hyper surfaces to have reasonable metrics on them. Wald's chapter on spinors says you need +--- for them though, I can't tell why and they made me give the book back after a year, so I can't check.

(Ryan) said...

As I understand it, high-energy theorists use +--- mostly due to Weinberg, whose book uses that convention. I don't know what Wald was up to.