Roger Penrose won the Nobel Prize for showing that black holes are an almost-unavoidable prediction of classical general relativity. Let's take a peek into what that entailed. 1/n

— Sean Carroll (@seanmcarroll) October 6, 2020

This aside got the biggest response of the whole thread, but it’s really not that mind-blowing! Just a funny wrinkle of how coordinates work in general relativity. 1/ https://t.co/gsMQU3hRBA

— Sean Carroll (@seanmcarroll) October 14, 2020