I've been thinking some more about the Hawking - Penrose Singularity theorem and was wondering if you could help me gain a better understanding of the assumptions they made when they wrote it, in 1970.
In Hawking's book, A Brief History of Time (chapter 3, page 25) he writes....
In 1965 I read about Penrose’s theorem that any body undergoing gravitational collapse must eventually form a singularity. I soon realized that if one reversed the direction of time in Penrose’s theorem, so that...