As part of the Expansion Questions Festival, I had a couple of questions, Ive red, I mean Ive read that theres a red shift in distant galaxies which supports the expansion idea, and wonder if light can shift over millions of years, as if it decayed into red or lower frequencies? Hum I guess not because gamma rays I think can come from distant galaxies(unless there was more of it when it was initially emitted?).
And Im puzzled by the expansion from what appears to have been a gigantic black hole, why did the universe expand from a black hole ish state and why doesnt the black hole expand the same way (unless the black hole does expand in an unperceived dimension?) ?
And in the expanding balloon analogy, there is no center of the universe from the surface perspective, but the balloon universe is expanding from the perspective of a central point outside the 2 dimensions of the ballooniverse a point outside the ballooniverse only perceived from another/extra dimension.