Raphael Bousso
bousso.bsky.social
Raphael Bousso
@bousso.bsky.social
Theoretical physicist: gravity, quantum information, black holes, cosmology. Professor at UC Berkeley
Reposted by Raphael Bousso
Academic freedom is "do you want the next generation of medical doctors to be trained?" It is "do you want vaccines?" It is "do you want your kids to learn true things?"
September 10, 2025 at 1:29 PM
Ask ChatGPT! But here what we need is the "generalized" second law, which involves areas of causal horizons. The GSL is a conjecture. If it was false, then ordinary thermodynamics would become meaningless if black holes exist. And we have considerable evidence by now for the existence of black holes
May 28, 2025 at 5:35 AM
If you don't take this limit, then the battle is veiled in fog. It's harder to formulate the GSL precisely. But it is also harder to claim that a bounce happened. The reason is that now spacetime geometry fluctuates, and saying a "a bounce happened" requires a well-defined notion of time ordering
May 28, 2025 at 5:29 AM
You can think of the theorem as saying that the Generalized Second Law implies a singularity and thus is incompatible with bounces and baby universes forming inside a black hole. Both of these conflicting notions are completely well defined only in the limit of infinitely many matter fields
May 28, 2025 at 5:29 AM