Which of the following is the best answer to the question,"Why does the Sun shine?"
A)As the Sun was forming,nuclear fusion reactions in the shrinking clouds of gas slowly became stronger and stronger,until the Sun reached its current luminosity.
B)As the Sun was forming,gravitational contraction increased the Sun's temperature until the core become hot enough for nuclear fusion,which ever since has generated the heat that makes the Sun shine.
C)The Sun initially began making energy through chemical reactions.These heated the interior enough to allow gravitational contraction and nuclear fusion to occur.
D)The Sun initially began generating energy through nuclear fusion as it formed,but today it generates energy primarily through the sunspot cycle.

Question

Quizplus · Accepted Answer

Option B is the correct answer as it describes the process of gravitational contraction increasing the Sun's temperature until the core becomes hot enough for nuclear fusion, which generates the heat that makes the Sun shine. This is the commonly accepted theory for the Sun's energy generation. Options A and C have some elements of truth but are not complete explanations. Option D is false as the sunspot cycle does not have a significant impact on the overall energy generation of the Sun.

Which of the Following Is the Best Answer to the Question,"Why