Tom Holland

And this is a man called Archimedes.

And Dominic, I know you love a mathematician and an engineer, don't you?

And Archimedes is...

I mean, he's kind of hailed by Leonardo, by Galileo, by Newton as the greatest, the goat.

Is that correct?

I mean, it is absolutely one of the most famous stories in science up there with, you know, an apple hitting Newton on the head.

And it does actually feature Heron, the ruler of Syracuse, who, according to a much later writer, was actually a kinsman of Archimedes.

So, you know, that would suggest a kind of closeness between them.

So the story goes, and I know that I can see the excitement on your face, the prospect of a... Yeah, give me a scientific lecture.

Yeah.

So Huron has commissioned a golden wreath.

as an offering to the gods.

And this wreath is delivered by the craftsman and it weighs exactly what it's supposed to weigh.

But here on, very astute man, he suspects that he's being ripped off and that what seems to be pure gold might actually contain quite a lot of silver, that it's been debased.

And so he gets Archimedes on the case, obvious person to turn to.

And Archimedes retires to his bathtub to ponder the problem.

And to quote Nicholas Nicastro in his fantastic book on Archimedes, just come out, Archimedes' Fulcrum of Science.

As Archimedes sank into his tub, he perceived that the water he displaced was equal to the volume of his body he had submerged, not his weight.

So to the degree that I understand it, what then happens is Archimedes takes a bar of gold and a bar of silver, and each one is equal exactly in weight to the wreath.

And he puts them both in his bathtub.