Question

How can we determine the age of the universe as 13.8 billion years if we have not thoroughly examined our solar system only and our the other reason is our observable universe's area is much smaller than the actual universe.

Answer 1

Dear Student ,

The universe cannot be younger than the objects contained inside of it. By determining the ages of the oldest stars, scientists are able to put a limit on the age.Thus by measuring the age of universe (i) how fast it is expanding or (ii) how old the objects are formed in universe scientist can predict that the approximate age of our universe is 13.8 billion years old .
Regards