The ratio of Carbon-14 remaining indicates the times since the death of a living substance.
Carbon-14 only works for things between 3 and 40 thousand years old. Carbon dating is based on an isotope of carbon, carbon 14, that's unstable. We breathe in carbon dioxide, we eat carbon, we take in carbon and so our bodies continually renewing our supply of carbon 14.
This is called the half-life—the amount of time required for one-half of a given number of atoms to disintegrate. The plot of the number of tiles as a function of the number of turns looks like this: Again, I made radioactive spheres disappear when they decayed.
Carbon dating uses an unstable isotope of carbon to find the date of dead substances.
This isotope Carbon-14 has a half life of 5,700 years.
I know can be hard to wrap your head around, so let's model it with a six-sided die. You can use Lego bricks, pennies, beans—anything you can easily count. Every time you roll a one, put that object into a separate pile.
Count the remaining objects and repeat the process until half of them have decayed. It took a while, but we finally got pretty close to 40 tiles left.
When an element undergoes radioactive decay, it creates radiation and turns into some other element.
Of course, the best way to understand something is to model it, because the last thing you want to do at home is experiment with something radioactive. Before doing any modeling, you must first understand one key idea: Each atom in a sample of material has an essentially random chance to decay.
Carbon-14 has a half-life of 5,730 ± 40 years— during the succeeding 5,730 years.
Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.
To determine the age of a sample, the SCAR technique uses a highly stable infrared laser to excite carbon dioxide molecules in a mirrored cavity.