Look at almost any galaxy beyond our neighborhood and it’s moving away from us, and the farther away it is, the faster it goes. It’s easy to take that to mean we’re sitting at the middle of some huge explosion. We’re not, and this one is meant to show why.

Galaxies aren’t flying out through space. Space itself is growing, a little bit everywhere at once, so the distance between any two galaxies keeps getting bigger even if neither of them is going anywhere. A galaxy twice as far away has twice as much space between you and it doing the stretching, which is why it seems to move away twice as fast.

Every so often the view travels to a different galaxy, and from there you see the exact same thing. Everything recedes from the new spot too. It doesn’t matter where you stand. Any galaxy would swear it’s the center, which means none of them is.

Not everything spreads out, though. Galaxies that are close enough to be held together by their own gravity stay in their clumps. It’s the big empty gaps between the clumps that stretch.

The colors tell you about speed. Nearby galaxies look warm white, and the farther out you go the redder they get. The little wavy lines are light traveling between galaxies, and as space stretches, so does the light, pulling its waves longer and shifting it from blue toward red. Some of it never makes it, because the gap grows faster than the light can cross it.

The graph in the corner shows how big the universe is over time. Early on, gravity was slowing the expansion down. Then about six billion years ago dark energy took over and it started speeding up, and it’s been speeding up ever since. You can watch it happen as the galaxies first slow their drift, then start pulling away faster.