Complex Numbers

Universal

PROMPT September 28th

Today’s prompt is from Cass--Autumn Spirit !

Write about what fascinates you about space and/or the universe.

Are you kidding me?

Regular readers will know that the answer to this question is "everything."

There's a lot of everything. I mean, sure, space is mostly empty... well, not really, because of vacuum energy.

It's way above my pay grade, but from what I understand, it turns out that everywhere, all the time, the universe is creating particle-antiparticle pairs that then proceed to annihilate each other within a time period so tiny that it's hard to imagine. Well, most of the time, that is. Sometimes, based on what Stephen Hawking hypothesized, such a pair pops into existence right at the event horizon of a black hole. The black hole sucks one of the pair into its... whatever happens in there, while the other now exists in our universe. It's more complicated than that, of course, but that's the gist of it.

Point is, even "empty" space is interesting - though I probably wouldn't feel the same way if I were stuck on a spaceship plowing through it; that would become very boring very quickly, once the whole "holy fuck I'm on a spaceship" excitement faded.

Want to know something cool? We've seen a black hole tearing a star apart. No shit. Here's Phil to explain it.  

Well, a black hole ate a star. (!!!) From the data, it looks like it was a supermassive black hole, about six million times the Sun’s mass, sitting in the center of that distant galaxy. A star got too close, and the gravity from the black hole ripped it apart.

This part cracks me up: These are called tidal disruption events, or TDEs, perhaps the most prosaic and mundane name for one of the Universe’s most violent and catastrophic events.

Tides are what astronomers call the effect of gravity changing with distance. As you move away from a massive object the gravity you feel from it gets weaker. A black hole has ferocious gravity. A star is a big object, and so if it happens to have a particularly unfortunate trajectory that takes it close to a black hole, the side of the star closer to the black hole feels a far stronger force of gravity than the side of the star facing away from the black hole. The overall effect is a stretching, literally pulling the star apart like taffy.

So yeah, that happens. It doesn't happen a lot - the thing people miss about black holes is that past a certain distance from them, they act just like any other source of gravity, so you have to get really lucky (or from the point of view of the star, unlucky) - but given that we can see something like 200 billion galaxies, and these events give off so much energy that you can see it happen from far, far away, it's inevitable that we'd see one eventually.

Also, no, it's probably not going to happen in our own galaxy anytime soon. They've imaged a lot of the stars around our own galaxy's central black hole, and they're pretty sure it's not about to dine on one of them. If it did, though, I'm not sure if 23,000 light years is far enough away.

That's just today's news, by the way. Or, okay, technically yesterday's, and if you want to get relativistic about it, it's news from 375 million years ago, but the point is this is only the most recent thing I read about shit going on in the universe.

As fascinating as it is that we can collect data from such an event and still have a pretty good idea what's going on, there's something even more fascinating: all the stuff we don't know. And all the stuff that we're wrong about, which gives us the opportunity to improve our understanding.

Space is, as Douglas Adams once wrote, big. “Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.” It is, in fact, so big that there's no way to see it all. It's a little bit like my quest to visit all the breweries in the US: even if you manage to do it, by the time you think you're done, new stuff has popped up and old stuff is gone, so you just have to keep trying.

That's the truly amazing thing about space: never-ending discovery. Almost certainly, at some point, we'll find evidence for life (not necessarily sentient life, but life) beyond our biosphere. That will be cool, and it will teach us a lot about our own biology. Then we'll discover more, somewhere else, and that'll teach us something different. And so on. Things we can't imagine, even though we do our best.

Yes, there are things about our own planet we don't fully understand, depths we haven't plunged. Nor do we fully understand ourselves; it's possible that we cannot do so, but I don't think we've hit the philosophical limits yet. There are over seven billion of us, though, and I'm confident in our ability as a species to multitask - and what we discover "out there" could also shed light on what's going on "down here."

I'm going to end this now, or I'll be writing here all night, and no one wants that. I've said a lot more about space in other posts, and as long as I stay alive I'll certainly have more to say in future installments. I'll just note one more thing, something that's been said before by way smarter people than me: we are "space." Every atom in our bodies (save for hydrogen) was forged in the heart of a star somewhere, sometimes in its death throes. We are, in a literal sense, made of star material. To understand us, we have to understand our environment - and our environment, ultimately, is the entire universe.