PDA

View Full Version : curvature space time


alejandrito29
Apr19-10, 10:09 PM
hello
i understand that in a flat space the metric is \eta_{uv}dx^udx^v...i know that this means that the light follows straight geodesic in this space time...

but ¿what would means that metric is f(t)\eta_{uv}dx^udx^v where f(t)=infinite in t=0 and f(t)=0 in t=infinite.....obvious i understand the matematics, but physically ¿what means?.....for example..¿what means that in bing bang in t=0 f(t)= infinite????

FrankPlanck
Apr20-10, 05:26 AM
hello
i understand that in a flat space the metric is \eta_{uv}dx^udx^v...i know that this means that the light follows straight geodesic in this space time...

but ¿what would means that metric is f(t)\eta_{uv}dx^udx^v where f(t)=infinite in t=0 and f(t)=0 in t=infinite.....obvious i understand the matematics, but physically ¿what means?.....for example..¿what means that in bing bang in t=0 f(t)= infinite????

It sounds a little bit strange to me.
Anyway probably f(t=0)=infinite it's the Big Bang singularity, a point with infinite density (so the metric), but it's a very raw treatment.