mike thanks very much superb description.... btw the hubble constant was just refined to about 71.something +/- 3.2 ish in a spate of five papers to be published soon. the groups used lensing of large quasars i believe where the bent light could be resolved into 4 or 5 spots per quasar ( if i am reading this correctly) which makes for a very highly refined distance measurement.... i have lately become fascinated with cosmology ... reading penrose, eddington etc... unfortunately, i still cannot get my brain to wrap around the mathematics of singularities and event horizons... though , when i am "horizoned" by another car on track.... I KNOW IT!!
FRANK