The End of Everything (Astrophysically Speaking)

by Katie Mack

As an aside, the fact that pretty much all the hydrogen in the universe was produced in the first few minutes means that a pretty large fraction of what you and I are made of has been hanging around the universe in one form or another for almost as long as the universe has been here. You may have heard that “we are made of stardust” (or “star stuff” if you’re Sagan), and this is absolutely true if we measure by mass. All the heavier elements in your body—oxygen, carbon, nitrogen, calcium, etc.—were produced later, either in the centers of stars or in stellar explosions. But hydrogen, while the lightest, is also the most abundant element in your body by number. So, yes, you hold within you the dust of ancient generations of stars. But you are also, to a very large fraction, built out of by-products of the actual Big Bang. Carl Sagan’s larger statement still stands, and to an even greater degree: “We are a way for the cosmos to know itself.”

in the core of a burned-out, collapsing star, there are so many atoms, pressed so tightly together, their electrons start to get antsy. At those kinds of pressures, the electrons aren’t bound to specific atoms, but rather are packed in together in a big atomic mess so crowded that they have to jump to higher and higher energy states to keep from all being in the same one. This creates a kind of pressure, called electron degeneracy pressure, which is strong enough to halt the collapse of the star and create an entirely new kind of object: a white dwarf. A white dwarf is a kind of star that isn’t burning at all. It has no fusion. It is a solid object held up entirely by the quantum mechanical principle that electrons just don’t like each other that much. And it can persist, silently smoldering, for billions and billions of years,

“I’m sure you’ve heard this from many people,” Clifford Johnson tells me, nonchalantly, a few months later, “but I think we’re getting better at realizing one of the things we’ve been saying in string theory for a long time, which is that spacetime isn’t fundamental.” Oh, yeah. That small detail. Sure.

If the universe is going to end, one way or another, I concede that we may as well make our peace with it. Pedro Ferreira is way ahead of me on that one. “I think it’s great,” he says. “It’s so simple and so clean. “I’ve never understood why people get so depressed about the end, the death of the Sun and all,” he continues. “I just like the serenity of it.” “So it doesn’t bother you that we ultimately have no legacy in the universe?” I ask him. “No, not at all,” he says. “I very much like our blip-ness… It’s always appealed to me,” he continues. “It’s the transience of these things. It’s the doing. It’s the process. It’s the journey. Who cares where you get to, right?” I admit it, I still care. I’m trying not to get hung up on it, on the ending, the last page, the end of this great experiment of existence. It’s the journey, I repeat to myself. It’s the journey. There is perhaps some solace in the fact that whatever happens, it’s not our fault.