We don’ t know of any “center” because we can’t see any “outer limits”. We are somewhere inside the universe, and it’s really big. In order to tell in which direction is the center, if there is one, we must be able to see the outer edge or “boundary”, if there is one.

It’s similar to the way astronomers finally discovered the location of the center of our galaxy. They had to do a lot of calculations regarding the apparent and proper motion of many stars. This is how they discovered that we live inside a galaxy, that it has a center, that it is spiral in shape, and that it is rotating.

To say that our universe does “not” have a center, simply because we don’t know where it is, would be like a 16th Century astronomer saying that we live inside a “circular universe” because they see the Milky Way loop around the earth. Herschel thought we were in the center of a “ring shaped” universe. That’s because he didn’t know about the motions of the stars, and he didn’t realize we were revolving around the center of a much larger galaxy than he was aware of in the 1700s. Some astronomers in the 19th Century said we lived in an "infinite" universe and they didn't know our galaxy had a center. They didn't even know it was a separate galaxy. Some thought it was the whole universe. In 1916 Einstein said all the stars were "fixed", because he didn't know they were moving.

Don’t believe any astronomer who tells you they know “exactly” how big and how old the universe is. This estimate changes about every 20-50 years, and it has been changing for the past 500 years. It has changed all during my lifetime.

Ned Wright doesn't know whether there is a center or not.