Originally posted by twhitehead
Well whoever you heard it from is either outright wrong, or didn't tell you the whole story.
Space expansion cannot be measured in units of speed. Space expansion must be measured in units of proportion. So for example space might grow 1% per year. The only way you can bring speed into the measurement is if you say space is finite, or you are talking a ...[text shortened]... timate the relative velocity between us and a point on the edge of the current visible universe.
I mentioned in a post being at a talk at Bell Labs given by Alan Guth. He said the BB started at basically zero size, I imagine not exactly zero but close enough for government work🙂 and expanded to the size of a football in something like 10^-23 second, something like that anyway.
I used those figures and came up with that number, 22 orders of magnitude faster than c 'growth' for that time period only.
I was able to mention that during a question and answer session, I was almost unable to speak, I was so nervous, and he said and I quote "Well, you did your arithmetic right'
I asked him that question about the speed of light limit and he answered that does not apply to space, only to matter and electromagnetic radiation and such, but space itself has no 'speed' limit. And just measuring the 'speed' by measuring such effects as doppler shift and the like.
So he was saying at least in the first tiny moments of the BB it was about that order of magnitude but exponentially slowed the 'growth' rate which has slowed down to this day, the speed up at 5 billion years ago notwithstanding.
Now they think it is still cranking out about 3 c or so. Meaning the universe is several times larger than telescopes can see, which we see out to about 14 billion light years but light from a much larger volume has not and will not reach us and so we will never actually see that stuff with telescopes.
Anyway I got that more or less from the horses mouth. Guth was a biggie in BB stuff and inflation in particular.