Mad Question that just ocurred to me

[max-greece]

-we wouldn't, we couldn't

?
(I'm assuming you mean to express a situation in which "locally" we observe expansion -locally being the universe we see....but that universe being nested in some other "call it a space" that is contracting at a rate fast enough to nullify and exceed the locally observed phenomena if measured "globally" - without any other observed effects at present?)

I didn't fully understand your assumption but maybe this is what I mean a bit clearer.

Just for ease I am gong to assume a creator God as it helps the picture (its not really part of the answer).

So you have God who decided to make the universe on his desk. It starts as this highly energetic point and expands out from there. At some point God thinks - fuck me - this is taking over the whole desk - so he freezes it and then, in order to create the illusion of expansion within the universe - he makes everything within the universe shrink relative to him. So the universe is of fixed size in this story (although it could be shrinking itself - as long as it is shrinking at a slower rate than everything within it is) but it appears to be expanding from our POV.

The question is - how do we know it isn't?
The next question is - if we don't know why are we assuming this is not the case?
And the final point is - doesn't this solve the problem of what the universe is expanding into?

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I was thinking you'd be able to tell from spectral analysis of redshirt, but the way you've worded the question seems to imply that this might not be the case.

It would depend on the temperature you washed the redshirt at I think.

Redshift perhaps?



Photons are getting smaller too, and light speed is relative to the universe.

I don't think it works - but keep at it because I really want to know the answer.