(April 28, 2012 at 2:38 pm)Abishalom Wrote:(April 28, 2012 at 12:50 pm)FallentoReason Wrote:Abishalom Wrote:I don't "need" the earth to be 6,000 years old (nor did I ever say that) but you NEED for it to 4.5 billion years sold to fit your "slow processes over long periods of time" fantasy.The number 4.5 billion comes from geology i.e. the oldest terrestrial samples we have to date.
What method did they use?
As others have mentioned, they use radiometric dating. What they do is they measure how many radioactive isotopes there are left and because they know the decay rate of that isotope they know how old the rock has to be for there to be that many radioactive isotopes left.
I'm not sure what discipline you have followed in your life so maybe you're not as heavily trained in physics. Because I study engineering at university I had to do all the physics and maths subjects in high school. This radioactive decay stuff gets taught in grade 11 so it's basic stuff and a well known theory.
"It is the mark of an educated mind to be able to entertain a thought without accepting it" ~ Aristotle
