Stephen Wolfram

Well, actually, he didn't know molecules existed,

In his time, 1860s and so on, the idea that matter might be made of discrete stuff had been floated ever since ancient Greek times.

But it had been a long-time debate about, you know, is matter discrete?

Is it continuous?

At the moment, at that time, people mostly thought that matter was continuous.

And it was all confused with this question about what heat is.

And people thought heat was this fluid.

And it was a big muddle.

But Boltzmann said, let's assume there are discrete molecules.

Let's even assume they have discrete energy levels.

Let's say everything is discrete.

Then we can do sort of combinatorial mathematics and work out how many configurations of these things there would be in the box.

And we can say we can compute this entropy quantity.

But he said, but of course, it's just a fiction that these things are discrete.

So he said, this is an interesting piece of history, by the way, that, you know, that was at that time.

People didn't know molecules existed.

There were other hints from looking at chemistry that there might be discrete atoms and so on, just from the combinatorics of two hydrogens and one oxygen make water.

Two amounts of hydrogen plus one amount of oxygen together make water, things like this.

But it wasn't known that discrete molecules existed.

And in fact, the people...