Zwicky

Among Zwicky’s claims, the most relevant to this book is the role of neutron stars as stellar corpses. As we shall see, a normal star that is too massive to die a white-dwarf death may die a neutronstar death instead. If all massive stars were to die that way, then the Universe would be saved from the most outrageous of hypothesized stellar corpses: black holes. With light stars becoming white dwarfs when they die, and heavy stars becoming neutron stars, there would be no way for nature to make a black hole.

Atomic nucleus

The Internal Structures of Atoms

Fates of stars when they die

What happens with neutron stars

The question then is: How massive can a neutron star be? If it can be very massive, more massive than any normal star, then black holes can never form in the real Universe. If there is a maximum possible mass for neutron stars, and that maximum is not too large, then black holes will form—unless there is yet another stellar graveyard, unsuspected in the 1930s.