First, in a flat, matter-dominated cosmos, the age of the universe is 2/3 H₀^-1. For H₀ ~ 70 km/s/Mpc, that age is cosmologically calculated to be >9 Gyr.

 

Second, our sun has a B-V color index of ~0.6, approximately the MS Turn-Off, of the Globular Cluster 47 Tucanae:

 

And, GCs are nearly as old as our universe, i.e. ~9 Gyr for a flat, matter-dominated cosmology.

 

QUESTIONS:

 

• First, if our cosmos turns out to be nearly flat, and mostly matter-dominated; then, would not GCs be ~9 Gyr old; and would not our sun's MS lifetime be about ~9 Gyr as well ?
  
• Second, if our sun's MS lifetime is typically predicted to be ~10 Gyr; and, if our sun represents the MSTO of ancient GCs, nearly as old as our universe; then, would not our universe be predicted to be ~10 Gyr old ? And, for an observed H₀, would that solar-and-GC age not determine the cosmology, i.e. closer to [math]\Omega_M \approx 1, \Omega_{\Lambda} \approx 0[/math], for which the universe's age is ~9-10 Gyr ?
  

but of course 'matter dominated' isn't the only option

 

http://en.wikipedia.org/wiki/Friedmann_equations#Useful_solutions

 

I favor w = -1/3

 

and therefore a(t) = t

Edited November 27, 201114 yr by granpa

So I'm not wrong, i.e. if our actual cosmos, is actually dominated, by actual normal matter, then (1) GR says our actual space-time fabric is ~9 Gyr old; and (2) our star cannot possibly have a MS lifetime >9 Gyr, since sunlike stars have already reached MSTO in halo GCs ? (In fact, are there not GCs even older than 47 Tucanae, i.e. w/ redder MSTOs ? If so, then stars smaller than our sun have evolved off MS in <9 Gyr, so that our sun must have an even shorter lifespan.)

 

For the record, some studies have shown, that WDs may not be as old, as numerical simulations suggest. If our universe was actually ~5 Gyr younger than current-convention demands, then stars in our universe would, seemingly, have to be >5 Gyr younger too.

Edited November 27, 201114 yr by Widdekind