Questions on the age of the sun necessarily hinge on how it produces its enormous energy. Long-age evolutionists favor thermonuclear fusion, the only known process that could last for billions of years. Young-age creationists counter that the evidence for fusion is scanty at best, and many have readily adopted data which seemsto show that the sun is shrinking. If so, it could be heating itself by gravitational collapse instead of fusion. However, such data is probably in error, and, in any case is so much larger that the rate actually necessary to produce the sun's heat as to be irrelevant. The sun may be heated by gravitational collapse, bu fusion, or a combination of both - there is simply not enough evidence to tell. The sun is not an age indicator one way or the other.