Dating is a science too
And so over the last few years, we’ve been working quite hard on improving this pre-treatment chemistry.
That means that, every 5,568 years, half the radioactive carbon in the bone, or the charcoal that we find in an archaeological site, has decayed back to its parent isotope, nitrogen-14.
So basically 10 half-lives is the limit of any radioisotopic dating method.
So when you get down to 30,000 years ago, you’ve got about 3% of the amount of radiocarbon that you’ve got in the present day, just 3%.
About 20% of your bone is protein, and the rest of it is a cement.
And the protein is the best material that we can get for dating.