The faint young Sun paradox or problem describes the apparent contradiction between observations of liquid water early in the Earth's history and the astrophysical expectation that the Sun's output would be only 70% as intense during that epoch as it is during the modern epoch. The issue was raised by astronomers Carl Sagan and George Mullen in 1972. Explanations of this paradox have taken into account greenhouse effects, astrophysical influences, or a combination of the two.
Read more about Faint Young Sun Paradox: Early Solar Output, Greenhouse Hypothesis, Alternatives
Famous quotes containing the words faint, young, sun and/or paradox:
“The morning comes to consciousness
Of faint stale smells of beer
From the sawdust-trampled street
With all its muddy feet that press
To early coffee-stands.”
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“And life must be hastening away;
You are cheerful, and love to converse upon death:
Now tell me the reason, I pray.”
“I am cheerful, young man,” Father William replied;
“Let the cause thy attention engage;
In the days of my youth I remembered my God,
And He hath not forgotten my age.””
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