The Beautiful Simplicity Of Parallax

Terence is bored. The grown ups are talking about anything and everything but fishing.

Parallax for example. And Mars and the moon.

Yes, says Jérôme. I was sent to Berlin, to take observations and determine their distances.

And did you? asks David.

Yes. Shortly after that I was elected to the Prussian Academy, says Jérôme. I was only nineteen. It was a great honour. I was able to discuss science with Maupertuis and Euler, and of course Vello here.

My, my, says David. I had no idea Vello knew about parallax.

Simple geometry, says Vello, airily. A child can understand it. Terence, what do you know about parallax?

Terence reaches under his polka dot jersey and unhooks his kingfisher photo from the top band of his lap lap. It is folded in the middle. He straightens it out.

This is my parrot, says Terence. It's only a photo.

I said PARALLAX, says Vello.

He's called Parallax, says Terence. Look he's moving.

Terence flaps the wings of the photo.

And yes, Parallax is moving.

That's not an example of parallax, says Jérôme. Come here, Terence.

Jérôme places a cake crumb on the table.

Observe it from here, says Jerome. And now come to the other side of the table. Now we can establish its position.

But, says Vello. Doesn't it have to be moving?

Not if Terence is moving, says David. At least that's my opinion. What do I know?

Can I eat it? asks Terence. Then it will have a moving position.

All right, eat it, says Jérôme, giving Vello a look.

What's that look? says Vello.

Even a child can understand it, says Jérôme.

And then can we go fishing? asks Terence, now that he has the adults' attention.

Fishing? says Jérôme. What makes you think....?

They SAID, says Terence.

David and Vello look blank. They don't remember mentioning fishing.

As it happens, says Jérôme, I am quite keen on street fishing. Would you like to come with me and do some street fishing?

Yay! says Terence.

What is street fishing? asks Vello.

Allow me to enlighten you, says Jérôme. I'll get the fishing rods and lures, and we'll do it.

Terence is excited. He folds Parallax in half, and shoves him back under the band of his lap lap.

He is ready for fishing.