Robin Williams

Professor, could you introduce me to your isotope?

Certainly.

They're everywhere.

I mean, you're a big bag of elements.

You know that, your water and your carbon and your nitrogen.

But you're also a big bag of isotopes, and so am I. And isotopes exist for most elements, and all they are is that element, so the number of protons.

with a different number of neutrons.

So let's take hydrogen, poor old little proton, no neutrons.

There are three isotopes.

So deuterium has another neutron, tritium has two neutrons.

And so because of that, they behave differently in natural cycles.

When you breathe in, when you breathe out, you're changing your oxygen, your hydrogen isotope composition.

Now, you remind me somewhat of Sherlock Holmes, who's looking at everything, including the dirt or sniffing the air, and from that getting clues on bigger stories.

Is that roughly it?

I think that's true.

I mean, you don't hear about isotopes a lot, but they're behind most things.

So when you hear about a temperature record from an ice core in Antarctica, it's isotopes, it's not temperature.

When you think about sea level in the past and how we know that, it's isotopes, it's not sea level, they're just reconstructed as that.

I tend to work more in environmental records, so using isotopes to look at vegetation and fire in the past.

We also can use it to look at what you eat when you're dead.