[permille42]

My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion.

The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter.

It is still a valid theory but I myself don't understand the physics of what is observed well enough to be convinced this is true. I believe that they are seeing something similar enough that it could be perhaps a "localized bang" or something like that.

The main evidence used as "proof" of the big bang is the observed data seeming to show that the everything in the universe is "dispersing" slowly. That is at least what I've heard claimed.