Our view of a small region of the Universe near the northern galactic cap, where each pixel in the image represents a mapped galaxy. On the largest scales, the Universe is the same in all directions and at all measurable locations, but distant galaxies appear smaller, younger, and less evolved than the ones we find nearby. (SDSS III, DATA RELEASE 8)

Ask Ethan: Where Is The Center Of The Universe?

When people learn the Universe is expanding, they want to know where the center is. The ‘answer’ isn’t what they expect.

There are two things that people learn about the Universe that surprise them more than any other: that the Universe hasn’t existed forever but only for a finite time since the Big Bang, and that it’s been expanding ever since that event took place. Most people intuitively hear that “bang” and picture an explosion, and then conceive of expansion like they would visualize shrapnel hurled outwards in all directions. It’s true that the matter and energy in the Universe began in a hot and dense state all at once, and then expanded and cooled as all the various components sped away from one another. But that doesn’t mean the “explosion” picture is correct. We got a very good question from Jasper Evers, who ponders:

I am wondering how there isn’t a center of the universe and how the cosmic background radiation is [equally] far away everywhere we look. It seems to me that when the universe expands… there should be a place where it started expanding.

After all, what this question is asking is exactly what aligns with our experience whenever we encounter an explosion.