How Fundamental Is General Relativity in Understanding Black Holes?

[lalbatros]

Dear all,

The possibility of black holes can be traced back to a special solution of the Einstein's equations, the famous Schwarzschild metric in 1916.

I find this very impressive, since at that time, the GR was a very young theory and it would have been more than natural to be skeptic about such a solution and the theory that leads to this solution.

I would like to know which aspects of GR, which 'ingredients', are the root cause for the Schwarzschild solution and the discovery of black holes. Or in other words, how much of GR is needed to come to the idea of black holes.

Am I right to say that clocks slowing down in a gravitational field is a consequence of the equivalence principle and SR? And would it be right the say that black holes are the consequence of that in the limit of large gravitational fields? Could the Schwarzschild radius be derived from such a simple analysis, and how justified could it be?

Michel

 

[pervect]

There was quite a bit of skepticism about black holes, and our understanding of them has improved considerably from the early days.

For instance, in some of the early papers, it was thought that the event horizon was a singularity of some sort, rather than an ill-behaved coordinate system. Also, early views of "black holes" tended to view them as "frozen stars".

To actually solve the metric for black holes, one needs the complete Einstein field equations, G_uv = 8 pi T_uv, that relate curvature to matter density.

I'm not sure how much one can derive about their proprerties using only the equivalence principle, unfortunately.