Concept explainers
(a)
The age of the universe for a Hubble constant of
(a)
Answer to Problem 21Q
Solution:
20 billion years.
Explanation of Solution
Given data:
The Hubble constant is
Formula used:
The relation between the age of the universe and the Hubble constant is given by the following expression,
Here,
Explanation:
Recall the relation between the age of the universe and the Hubble constant.
Substitute
Upon further solving,
Conclusion:
Therefore, the age of the universe is 20 billion years.
(b)
The age of the universe for a Hubble constant of
(b)
Answer to Problem 21Q
Solution:
13 billion years.
Explanation of Solution
Given data:
The Hubble constant is
Formula used:
The relation between the age of the universe and the Hubble constant is given by the following expression,
Here,
Explanation:
Recall the relation between the age of the universe and the Hubble constant.
Substitute
Upon further solving,
Conclusion:
Therefore, the age of the universe is 13 billion years.
(c)
The age of the universe for a Hubble constant of
(c)
Answer to Problem 21Q
Solution:
10 billion years.
Explanation of Solution
Given data:
The Hubble constant is
Formula used:
The relation between the age of the universe and the Hubble constant is given by the following expression,
Here,
Explanation:
Recall the relation between the age of the universe and the Hubble constant.
Substitute
Upon further solving,
From the calculation in all the three parts, the value of
Conclusion:
Therefore, the universe must be older than the oldest stars of the globular cluster. So, the Hubble constant should be such that the age of the universe is older than that of the oldest star in the globular cluster.
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Chapter 25 Solutions
Universe
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