A creationist wrote:

The research by Creation scientists is NOT all religion – ie. Christianity. Creation Scientists are looking at the same evidence, but are coming to different conclusions.

Rapid rocks – Granites – they do not need millions of years of cooling.

http://www.answersingenesis.org/creation/v21/i1/rocks.asp

Ken Smith responded:

Now that’s very interesting.

In the 19th century Kelvin, claimed as a “creationist” by Answers in Genesis and assorted other groups, made some calculations on the age of the earth, and the time needed for rocks to cool down from an initial molten state to their present temperatures. Depending on the assumptions he made, he got answers between 20 million yerars and 100 million years. This was seized on by creationists of the day (and today, as well) as proof that the earth could not possibly be billiuons of years old.

The whole work was, of course, invalid, because neither Kelvin nor anyone else at the time was aware that radioactive decay provided heat. Radioactivity wasn’t discovered until 1896, well after Kelvin had done his work. But that’s not all.

I’d be interested to know how much you know about the conduction of heat in solids.

For example, have you read the classic work “Conduction of Heat in Solids” by two Australian mathematicians, H. S. Carslaw and J. C. Jaeger (Oxford Univ, Press, 1959) ?

If granites don’t need millions of years to cool, then they don’t need years to heat up, either.

One problem I set students in classes on diffusion theory was to investigate the annual heating/cooling of rocks as temperatures vary between winter and summer.

The variation in temperature becomes undetectable less than a metre below the surface.

This is genuine science, so claims by creationists that rocks don’t need millions of years to cool are just so much twaddle.

Salaam Ken Smith

— Dr Ken Smith – Christian, husband, unpaid mathematician, skeptic, … `Similarly, it is not open to the religious-minded to say: “God or Natural Selection,” or to offer as logical opposites “The Bible or Darwinism”.’ J. Arthur Thomson, in “Science and Religion”