> > There is no negative mass, so you can always infer the one real arrangement of stuff inside from the warping of space-time at the surface of your box.
> Positive mass does not make this argument work. Two bodies in GR can have different distributions of mass but identical exterior geometry. A counterexample is two spherically symmetric, uncharged bodies with the same total gravitational mass but different radial density profiles. By Birkhoff’s theorem, their exterior vacuum geometries are identical.
I thought I understood the holographic theory better after this article. But now it's clear I don't.
> Positive mass does not make this argument work. Two bodies in GR can have different distributions of mass but identical exterior geometry. A counterexample is two spherically symmetric, uncharged bodies with the same total gravitational mass but different radial density profiles. By Birkhoff’s theorem, their exterior vacuum geometries are identical.
I thought I understood the holographic theory better after this article. But now it's clear I don't.