Was space always expanding at its current rate? If the rate of expansion is slowing, in the past it was expanding faster. What implication does this have for the speed of light? Was the speed of light proportionally faster also? Would that mean our estimates of distance based upon redshift are too small? Or... When the universe was smaller, was it actually denser? Or were all the cosmological constants equally compressed making all measurements the same then as now? (IE. A 1m ruler would, in the past, still read 1m even though it was smaller.)? If we say it would (now) take n years for a photon to circumnavigate the universe, would it also take n years when the universe was half its current size, or would it take n/2 years? Is the time it takes a photon to circumnavigate the universe a constant? Regardless of the size of the expanding universe? Does that mean that (by todays standards) light used to travel slower? Would that mean our estimates of distance based upon redshift are too large? And... About 300000 years after the big bang, the universes fell below a critical temperature allowing atoms to form, making space transparent and releasing the cosmic microwave background radiation still detectable today. So why were only hydrogen and helium formed. Why are heavy elements only made in stars and novas? Wasnt the big bang fireball hot enough?