Why would a value of 500 km/s/Mpc for the Hubble constant ...

[jho37]

Why would a value of 500 km/s/Mpc for the Hubble constant contradict theories of stellar evolution?
 
  What will be an ideal response?

Question 2

How might we tell whether the Universe is open or closed?
 
  What will be an ideal response?

[jazzlynnnnn]

Answer to Question 1

The Hubble time for this value is 2 billion years. Astronomers know of globular star clusters that are significantly older than 9.5 billion years.

Answer to Question 2

According to general relativity, the overall curvature of space-time is determined by the average density of matter plus energy in the Universe. Cosmologists could calculate that space-time is flat if the average density of the Universe equals a critical density. If the average density of the Universe is more than the critical density, the Universe must be closed; and if it is less, the Universe must be open.

[jho37]

Excellent

[kusterl]

Thanks for the timely response, appreciate it