That is interesting. Thank you.
Yes, it is perfectly reasonable to take that approach; to place an upper limit on any possible rotation, rather than try to disprove the universe is rotating. It would just not be scientifically possible to observationally “prove” that there is no rotation at all.
But, that does place a very tight bound on any possible rotation. I will need to read more of what he said. I wonder if the limit was determined by observations of the CMB or some other way.
I have read elsewhere that any significant rotation just after the BB (during the BB nucleosynthesis) would affect the production of light elements and the universe could not have evolved to be the way it is now.
There is a good discussion about this issue here.
Anyway, . . . if I take his highest value of 10-14 rad /yr, the universe would have rotated .0013 radians since the BB!
That is, the universe rotated less than one tenth of a degree in 13 Billion years.
It hardly seems enough to account for an energy equal to that needed to replace the cosmological constant, dark energy, with the claim of a centripetal force. But what do I know?
I am sure 006 will have all the answers in his book!