Is it at all possible that instead of being pushed away, we are instead getting pulled toward something huuuuuge via gravity? As if we are falling into something way greater than ourselves? I thought this was a wild idea but after I Googled it I found out that there is such a thing as a “Great Attractor”. Something 150 million light-years away is literally pulling all nearby galaxies towards it but no one knows exactly what it is.
So how do we know there aren’t any other Great Attractors, Greater Attractors, ad infinitum?
Well, if the sphere was there all along, yes, it’s possible. Very unlikely, but possible. If the whole universe is moving somewhere, we have no way to detect it. Note that this doesn’t exclude the Big Bang, that still happened even in your scenario.
It’s just one of those unprovable things - like whether there’s a God or whether we live in a Matrix. Unprovable and thus irrelevant.