Carbon dating doesn t work
As water freezes and each molecule falls into place, atoms that don’t fit in the forming ice crystal are excluded. For example, zircon (a crystal) is perfectly happy to incorporate uranium, but excludes lead.
Impurities, such as dissolved air, are either forced out or concentrated in the last region to freeze. It so happens that uranium decays into lead with a half-life of 4.5 billion years.
By the year 2100, the atmosphere will have a radiocarbon age of 2,000 years old. If Graven's calculations are correct, carbon dating as we know it today will no longer be reliable by the year 2030.
Which means scientists won’t be able to use carbon dating to distinguish between new materials and artifacts that are hundreds or thousands of years old.
When things die they stop getting new carbon and the carbon-14 they have is free to radioactively decay without getting replaced.
Carbon-14 is continuously generated in the upper atmosphere when stray neutrons bombard atmospheric nitrogen (which is what most of the atmosphere is).
The reason carbon dating works is that the fresh carbon-14 gets mixed in with the rest of the carbon in the atmosphere and, since it’s chemically identical to regular carbon, gets worked into whatever is presently absorbing atmospheric carbon.
“Seldom has a single discovery in chemistry had such an impact on the thinking in so many fields of human endeavour,” one of Libby's colleagues wrote at the time, according to the Nobel Foundation.
Today, carbon dating is used so widely as to be taken for granted.