A decade ago, many astrophysicists thought that the oldest ...

[rmenurse]

A decade ago, many astrophysicists thought that the oldest globular clusters were 14-16 billion years old. Why did this create problems, and how did new Hubble and Hipparcos data resolve them?
 
  What will be an ideal response?

Question 2

How is the Schwartzschild radius calculated?
 
  What will be an ideal response?

[ju]

Answer to Question 1

The Hubble Time seemed to be only 10-12 billion years old, so how could these clusters be older than the universe? Hipparcos and Hubble clarified the Cepheid data, making the distances and ages of the globulars less, and the universe older, so that now we think the universe is about 13.7 billion years old, and the oldest globulars about a billion years younger.

Answer to Question 2

The Schwartzschild radius is roughly 3 km times the mass of the star in solar masses.

[rmenurse]

Thanks

[ju]

Welcome