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- Did the Big Bang happen at a point? 6 answers
So, we observe that galaxies are moving apart (on average) and the further away from us they are the faster they are moving away from us. If space was expanding that would explain this.
However, I imagine that if a primordial explosion happened then at some point close to where the explosion happened things would not move much, and they would be moving faster the further away you were from "ground zero".
But if we were not near ground zero there should be some anisotropy in the speeds we observe, is that correct? There should be a "ground zero" in the "explosion model", right??
However, regardless of the "ground zero" issue, do we (or could we) distinguish between a uniform "explosion" model and the idea that space is expanding?