For centuries humans believed that we were at the center of the universe. You can hardly blame them since the sun, the moon, and the stars visibly seemed to be moving around us while we stood still. But with time, we started tracking the movements of the planets with more detail and their movement didn’t make sense with a geocentric model of the universe. So we had to accept that we weren’t at the center of the universe.
The Universe is roughly the same everywhere with no special center or special region. It’s impossible for us to have a special place in the universe because the universe has no special places. Even the Big Bang didn’t have a “center”. The Big Bang happened everywhere! Matter of fact, the remnant radiation from the Big Bang is one of the best evidence we have for the large-scale evenness of the universe.
The energy from the Big Bang has had time to cool enough that it radiates in the microwave range and so is called the Cosmic Microwave Background. Here is what it looks like:
The most extreme color difference in the map represents a change of only 0.2 degrees across light years of the universe! That is very even!
The Big Bang kicked off the universe. So if the Big Bang was even, it makes sense to assume that the universe is equally even. But the Big Bang is also old. If the remnant radiation is evolving the same everywhere, then we can be even more sure that the universe looks the same everywhere.
But then you hear about the redshift of the universe. If we ignore things in our galaxy, then everything seems to be moving away from us. They are running away from us so fast that their color shifts similar to how ambulances change their sound when they are speeding away. That’s called redshifting and that’s how we know that they are moving away from us.
The Earth (and the Milky Way) are at the center of the map. Since the Milky Way is thin and flat, it obscures our vision in that thin midsection which is why there are no data points there. Where we do have data though, everything is moving away! The scale at the bottom doesn’t even have a color to represent anything moving towards us because nothing is moving towards us! The best we have are the purples who are staying put or only slowly moving away.
It almost feels like a reverse geocentric view–where we seem to be so bad that everyone wants to run away from us!
But, alas, we don’t get to be special even in a bad way. The reason all things are moving further away from us is that everything is speeding away from everything else! The universe is rapidly expanding everywhere.
The universe is expanding so much that one of the proposed ends to the universe is The Big Rip where space expands so much that atoms are ripped apart and even subatomic particles are separated by infinite space. I guess then the universe will truly be the same everywhere.