The first time I came to understand this was in Isaac Asimov's The Collapsing Universe, which described how stars form, function, and die, with the ultimate fat

The first time I came to understand this was in Isaac Asimov's The Collapsing Universe, which described how stars form, function, and die, with the ultimate fate of the very largest being black holes. <https://archive.org/details/collapsinguniver0000asim https://archive.org/details/collapsinguniver0000asim> Stars are a contest between gravity and the nuclear strong force, with stellar fusion creating the heat and pressure required to resist, at least for a time, the pull of gravity. The larger a star, the faster it burns through its hydrogen fuel. While brown dwarf stars may have liftimes in the trillions of years, our Sun will expend all its fuel in about 11-12 billion years (it's about half-way through that process now), and will gradually grow hotter and brighter as it does so (it's already about 25% brighter than it was when the Earth was formed). The largest stars have lifespans of only a few million years, roughly dating to when the proto-hominids diverged from their last common ancestor with chimpanzees, and far more recently than the dinosaurs died out. It's a useful lesson to recall that bigger and more energy-hungry does not necessarily mean longer-lived, and quite often means precisely the opposite. <http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/startime.html http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/startime.ht...> <https://en.wikipedia.org/wiki/Stellar_evolution https://en.wikipedia.org/wiki/Stellar_evolution>