Traveling to the center of the universe

 Space is big. Really 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, but that's just peanuts to space. - Douglas Adams, The Hitchhiker’s Guide to the Galaxy.

The nearest star other than the sun is Proxima Centauri, about 4.244 light years from Earth. If we could build a really good starship based on known physics, solve the big reaction mass problems, and maybe achieve 10% the speed of light -- way faster than anything we have today -- the ship would arrive in under 43 years.

You’re so slow, you’ll need a generation ship. Sure, high-speed travel slows down time, but at 10% light speed, that’s only about 1% difference. Now, that travel time is assuming no Alcubierre drive or other Star Trek physics tricks, no B5 Jump Gates and Hyperspace, no Dune-style folding space, etc.

All the things we’ve ever sent into space, Voyager 2, launched in 1977, is only the second one to have made it out of the solar system, into interstellar space, just last summer. Very few humans are spending any time thinking about travelling beyond the solar system.

And if you and your kids aren’t going to make it back to Earth, the trip better be worthwhile. Going to Proxima Centauri would be interesting, sure, but once you got there, there’s probably not much to do. Not just a lack of a good pub, but Proxima Centauri is a red dwarf star, and while it does have one planet, Proxima b, in its habitable zone, it’s unlikely to be habitable. The habitable zone of such a small star is so close, the planet becomes tidally locked, in a very short, fast, tight orbit of 11.2 days, and subject to about 2,000x the stellar wind we get here on good ol’ Earth.

Next, let’s just find the center of our galaxy. The center of our Milky Way Galaxy is about 26,000 light years from Earth. Still travelling at 10% the speed of light -- way faster than we currently travel -- this journey would take 260,000 years. At least 50x longer than the age of human civilization … but hey, maybe we improve our spaceship along the way, if we bring enough raw materials. And when your distant descendants get there? Everyone Dies!

There is a supermassive black hole in the center of the Milky Way Galaxy, about 4 million times the mass of the sun. Not where you want to park your generation ship after such a long trip.

So how about our nearest full sized galactic neighbor, the Andromeda Galaxy, affectionately called Messier 31 by some astronomers, NGC 224 by other astronomers. Well, technically, the Canis Major Overdensity, a dwarf galaxy, is actually the closest to us, even closer than the Milky Way’s galactic core, but the photos of Andromeda are much better! This galaxy is a paltry 2.537 million light years from Earth. So get back in that starship and you can get there in only 25.37 million years! And yeah, if you go to the center, Everyone Dies! Black holes at the center of galaxies seem to be analogous to stars at the center of planetary systems.

But even the starship Enterprise can’t get to Andromeda in any reasonable time. But you don’t have to actually go! Just wait here for about 3.75 billion years … it’s headed our way! Curiously, No One Dies, or at least almost no one … assuming anyone’s still around to die. As we’ve discovered just travelling to our nearest neighboring star, space is huge, and mostly empty.

So, now, on to the center of the universe … where is it? Can you see it? Damn … everywhere I look I see more galaxies! In fact, in nearly every direction, I can see objects as distant as about 13 billion light years.

Eureka! I think we must already be in the center of the universe!! I mean, most of us are at least suspicious that the world revolves around us as individuals. Those crazy flat-Earthers think Earth is in the center of the universe. Could it really be turtles all the way down?

Only, here’s the thing … the universe is old. How old? 13.772 billion years is our best estimate. Hmm … just a little older than those distant galaxies, eh? That’s the thing about looking out into space: you’re also looking back in time. So yeah, you think you’re at the center of the universe. If you were instantly zapped via long range teleportation beam to Tralfamadore (about 74,353 light years away), you would still be in the center of the universe. Go somewhere in Andromeda … still in the center of the universe. Go all the way the observable “end” of the universe … still in the center.