Even if humanity developed technology for interstellar travel, there’s still no chance we’ll ever get to visit dark corners of the observable universe. Space is simply expanding too fast for us to travel the distance necessary to actually see anything. You think driving through the desert is boring because there’s not much to see? Consider this: the average distance between stars is about 47 trillion kilometers (or 29 trillion miles), and in between that there’s pretty much just nothingness.
While the Milky Way is large—about 100,000 light years across— it only accounts for 0.00000000001 percent of the observable universe. Why can’t we go further than our own local group of galaxies? According to the video above, it has to do with the nature of nothing. Here’s where things get really complicated.
“Nothing, or empty space, isn’t empty, but has energy intrinsic to itself, so-called quantum fluctuations,” the narrator from “Kurzgesagt – In a Nutshell” explains. “On the smaller scale, there is constant action, particles and anti-particles appearing and annihilating themselves. You can imagine this quantum vacuum as a bubbling part with denser and less dense regions.”
And then you have to consider dark energy, and how only galaxies in our local group are bound to us gravitationally. Because of this, traveling from our group to another is virtually impossible. The more the universe expands, the larger the distance between us and other gravitational pockets becomes. Essentially, dark energy will push the rest of the universe away from us, causing other clusters of stars to become unreachable.
The next galaxy group is already millions of light years away, and because it’s moving away from us at obscene speeds, there’s just no hope of reaching it, even if we do create the technology for interstellar travel. The craziest part is that eventually the universe will fade from view, and there will simply be nothingness around us forever and ever.
With trillions of stars, however, the local group of galaxies is still plenty big for humanity, and the fact that we still haven’t left out solar system means there’s plenty to explore. Now, it’s just a matter of picking out a planet or two to call home.