In our local region of the Universe, the Virgo Cluster is a kind of center, its mass distorting everything around it, but the Universe as a whole has no center.
In one sense, the Universe has no center, but another way of looking at it is that everywhere is a center, especially if one is on the inside looking out.
Humanity can be quite a narcissistic species, so it’s no surprise that for most of our existence we’ve apparently believed that we live at the center of everything. Lots of people have looked at the world around them and concluded that they live in the center of a flat Earth and that the Sun, planets and stars revolve around them.
However, the idea that everything must have a center and that we are obviously at the center of things was so ingrained that we continued to believe that everything revolved around the Earth for several thousand years.
The hard-won Copernican Revolution moved the Earth off center, but for a time the Sun was . The Sun was relegated to the status of a modest star in the galactic suburbs only when it was noticed that the Milky Way was much denser in the direction of Sagittarius than anywhere else.
In the 1920s, as astronomers realized that the Milky Way was just one galaxy among more than we could count, humanity had to come to terms with the fact that our location was nothing special.
Our location in the galaxy is nothing special
At this point, it was still natural to believe that, whether or not there was any virtue in being close to him, he was just nowhere near us. This perception shook philosophy and did much to undermine faith in religion.
Then, however, Edwin Hubble, who had previously helped reveal the Milky Way’s status as an ordinary galaxy, noticed that the farther a galaxy is from us, the faster it recedes.
If everything moves away from us equally in all directions, maybe we were the center after all.
Scientists have realized that we need to think differently about the Universe. Describing it as a balloon that inflates so that everything gets further and further away from everything else may be useful as an introduction, but it is also misleading.
The universe has no edges, like the skin of a balloon, which would imply a center. It’s not a perfect analogy, but thinking there must be is a bit like our ancestors thinking their patch of land was the center of the Earth. Earth still has a center, of course, but no one lives there.
We have to think differently about the Universe
The nature of the Universe is so different from the everyday objects we encounter that we lack better metaphors to compare it to. However, cosmologists are convinced that the Universe has no counterpart in the center of the Earth. Also, there is no single place where the Big Bang happened, it happened everywhere.
On the other hand, a large part, probably most, of the Universe is hidden from us. This hidden universe is so far away that light has not had time to reach us since the beginning of the universe, he writes.
What we can see is called the observable universe, the area close enough that light could reach us in the roughly 14 billion years since the Big Bang.
We might expect the observable universe to be a sphere with a radius of 14 billion light-years, but because of the way space has expanded over this time, the radius is actually about 45 billion years.
