skip to content »

How to do carbon dating

Climate records from a Japanese lake are set to improve the accuracy of the dating technique, which could help to shed light on archaeological mysteries such as why Neanderthals became extinct.Carbon dating is used to work out the age of organic material — in effect, any living thing.

how to do carbon dating-72how to do carbon dating-75how to do carbon dating-11how to do carbon dating-7

But even he “realized that there probably would be variation”, says Christopher Bronk Ramsey, a geochronologist at the University of Oxford, UK, who led the latest work, published today in Science.A T-shirt made in 2050 could look exactly like one worn by William the Conqueror a thousand years earlier to someone using radiocarbon dating if emissions continue under a business-as-usual scenario.By 2100, a dead plant could be almost identical to the Dead Sea scrolls, which are more than 2,000 years old.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.As scrolls, plant-based paints or cotton shirts age over thousands of years, the radioactive carbon-14 that naturally appears in organic objects gradually decays.

The amount of carbon-14 decreases relative to the amount of normal carbon.

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.

This is fine, because when carbon-14 decays, it produces nitrogen-14. But you could imagine that if you knew that the sample started with 20 percent blue spheres and you knew their half-life, then you could determine the age by examining one frame from the animation.

a bad rap, what with radiation and fallout and nuclear waste and all. One of the coolest (OK, maybe the coolest) is using radioactive carbon to determine the age of old bones or plants.

To understand this, you must first understand radioactivity and decay.

The technique hinges on carbon-14, a radioactive isotope of the element that, unlike other more stable forms of carbon, decays away at a steady rate.