What carbon dating

19-Nov-2019 13:31

When those speedy protons hit atoms you end up with a few stray neutrons zipping around the place.

And when one of those energetic neutrons hits a nitrogen atom, the nitrogen spits out a proton.

From the moment we die the proportion of carbon-14 compared to non-radioactive carbon-12 in what's left of our bodies starts to drop as it gradually turns to nitrogen.

That's why radiocarbon dating is only reliable for samples up to 50,000 years old.Not only that, we top up our carbon-14 levels every time we eat.And plants top up their radioactive carbon every time they turn carbon dioxide to food during photosynthesis.Chemically, carbon-14 is no different from non-radioactive carbon atoms, so it ends up in all the usual carbon places — one trillionth of the carbon atoms in air, plants, animals and us are radioactive.All radioactive atoms eventually decay into something more stable, and carbon-14 decays into nitrogen.

That's why radiocarbon dating is only reliable for samples up to 50,000 years old.Not only that, we top up our carbon-14 levels every time we eat.And plants top up their radioactive carbon every time they turn carbon dioxide to food during photosynthesis.Chemically, carbon-14 is no different from non-radioactive carbon atoms, so it ends up in all the usual carbon places — one trillionth of the carbon atoms in air, plants, animals and us are radioactive.All radioactive atoms eventually decay into something more stable, and carbon-14 decays into nitrogen.It's not that the radioactive carbon in air or food doesn't decay, it does.