Principle Of Least Action

Arthur has one eye on the tatty paper, and one on the fallen ticket.

Well? asks Pierre-Louis Maupertuis.

They do look like runes, says Arthur. 

They do, says Pierre-Louis. I spent years trying to decipher them.

But you couldn't, says Arthur.

No I couldn't, says Pierre-Louis. 

Because they weren't runes, says Arthur.

Exactly, says Pierre-Louis. Waste of time. But I did other things as well. For example, I invented the principle of least action.

Impressive, says Arthur. I use that a lot.

He leans forward, pretending to scratch his left knee. At the same time he picks up Pierre-Louis' fallen ticket.

It's a mathematical concept, says Pierre-Louis, not an excuse.

Mm, says Arthur.

A ticket inspector is approaching, checking everyone's tickets.

Pierre-Louis looks up.

Pierre-Louis! says the ticket inspector. Heading home to Saint Malo?

I am, says Pierre-Louis. 

The ticket inspector looks at Arthur. 

Do you know you're sitting beside one of Saint Malo's most famous sons? asks the ticket inspector.

I'm learning, says Arthur. He's been explaining the principle of least action.

But did you know he took part in the battle of Mollwitz on a donkey? says ticket inspector.

No, says Arthur. 

Long story, says Pierre-Louis. I was subsequently taken prisoner by the Austrians.

And released, says the ticket inspector. He later returned to Berlin and became president of the Royal Prussian Academy of Sciences.

Pierre-Louis is beaming. remembering his donkey.

Well, best be getting on, says the ticket inspector.

Don't you want to see my ticket? asks Pierre-Louis.

Not at all! says the ticket inspector. I'm sure you must have one.

Very kind, says Pierre-Louis, who had been starting to feel in his pocket.

Arthur flashes the ticket he holds in his hand.

Enjoy the rest of your journey, says the ticket inspector, moving on.

Excellent fellow, says Pierre-Louis. Would you like to hear more of my donkey?

Arthur would not, but supposes he'll have to.