A Good Shellacking
two Trurls, and no way to tell which is which
EIGHT LINES
- KlapauciusMake me a Trurl. So like the real one that nobody could ever tell the two apart.
- The Wish MachineVery well, I will make one. Only, please, be gentle with him.
- KlapauciusBecause you are not the real Trurl.
- TrurlI am the real Trurl! I hid inside the machine, and had it carry me here.
- KlapauciusA machine that can make a number five screw can certainly make you.
- KlapauciusIt was very like you. Clever, too.
- TrurlI had to take it apart.
- KlapauciusAnd for that they give him a medal.
HOW IT IS MADE
The device is equality against identity. Two things can be equal in every field you can check and still be two things, or they can be one thing seen twice, and checking the fields will not tell you which. Klapaucius asks the wish machine for a Trurl so like the real one that nobody could tell them apart. The machine delivers, and from then on the story has two Trurls and no test that separates them. The Trurl in the cellar says he is the real one. The Trurl at home says the one in the cellar was a copy, and points at a few nuts and bolts on his floor.
The film keeps that question open on purpose. Every Trurl on screen is drawn by one function with one fixed set of ids, so the Trurl who climbs out of the belly door and the Trurl who opens his door the next morning are the same drawing, down to the wobble in the ink. Both speak with the same Kokoro voice at the same speed. The picture has no way to mark one of them as the copy, and it does not try. What each Trurl says is the only evidence, and Klapaucius believes whichever version lets him keep hitting.
The workshop has a grandfather clock that ticks through every scene there, and the wish machine hands out blue paint, sandpaper, a brace and bit, white paint and one number five screw from a door in its belly, each with a small chime that climbs a step higher than the last. The cellar is dark except for one hanging lamp that swings on its hook, and it is a hard, long room in the sound: every clang of the crowbar and the club rings and comes back. The beating is metal slapstick, clangs and dents and a head that booms like a drum, and the next morning the dents have been hammered flat and painted over. At the end the King's fanfare sags flat on its last chord, Klapaucius pulls down his blinds, and the canvas comes off his own machine: a wish machine, painted blue, not finished. Where a scene has the one line that matters, the camera goes in close and the delivery slows; the other lines stay wide and quick.
The timing file gs.json drives picture and sound together. It holds the start time of every spoken line and every cue. The picture code reads those times, and build_sound.py makes all the non-voice sound with numpy and scipy.
FOR THE BENCH
Make two objects, a and b, with the same fields: name: 'Trurl', dents: 0. Check a.name === b.name, then a === b. Now write copyOf(t) that returns a new object with the same fields, and hit(t) that adds one to t.dents. Hit the copy three times. Did the original change? Then try it with const b = a instead of a copy. Which test would Klapaucius need to run to know which Trurl was in his cellar, and is there any field you could add that a perfect copy would not also have?
Narration and dialogue paraphrase Stanisław Lem, “A Good Shellacking,” The Cyberiad. Nothing is quoted. Download the film.
THE SCRIPT
THE GIFT
Narrator. Someone was hammering on the front door of the constructor Klapaucius. He opened it, and found a round-bellied machine standing on four stubby legs.
Klapaucius. Who are you? What do you want?
The Wish Machine. I am a wish machine, sir. I grant every wish. Your friend Trurl, Trurl the Magnificent, sent me to you as a present.
Narrator. Klapaucius had mixed feelings about Trurl, and the word Magnificent annoyed him. Still, he let it in.
Narrator. He parked it by the grandfather clock, and went back to his own work, a low machine on three stubby legs, almost done.
The Wish Machine. Excuse me. I am still here.
Klapaucius. I know.
The Wish Machine. May I ask what you are building?
Klapaucius. Are you for wishes, or for questions? Blue paint.
Narrator. A little door opened in its belly, and out came a bucket of blue.
The Wish Machine. I hope the shade is right.
Narrator. Over the next hours he asked for sandpaper, then a brace and bit, then a pot of white paint, and one number five screw. Each came straight out of the belly door.
Narrator. At evening he threw a canvas over his work, and pulled a chair up opposite the machine.
Klapaucius. So. Every wish? Now, something harder.
Klapaucius. Make me a Trurl. So like the real one that nobody could ever tell the two apart.
THE COPY
The Wish Machine. Very well, I will make one. Only, please, be gentle with him.
Klapaucius. Of course, of course. Well? Where is he?
The Wish Machine. Already? A Trurl takes longer than a screw, you know.
Narrator. It did not take long. The belly door swung open, and a Trurl climbed out.
Narrator. Klapaucius looked him over, touched him, tapped him, and found no difference at all.
Klapaucius. Hello, Trurl!
Trurl. Hello, Klapaucius. Hold on. How did I end up here?
Klapaucius. Oh, you dropped by. How do you like the place?
Trurl. Very nice. What is under the canvas?
Klapaucius. Nothing much. Do sit down.
Trurl. I really ought to go. It is getting dark.
Klapaucius. So soon? But you have not seen my cellar.
THE CELLAR
Narrator. Klapaucius put an arm around his shoulders and walked him down the stairs. At the bottom he tripped him, sat on him, and tied him up.
Narrator. Then he picked up a crowbar, and went to work.
Trurl. Ow! Ow! What are you hitting me for?
Klapaucius. Because I enjoy it. You ought to try it some time.
Narrator. The next blow landed on top of his head, and it rang like a drum.
Trurl. Let me go, or I will tell the King, and he will lock you in his deepest dungeon!
Klapaucius. He will not. Shall I tell you why?
Klapaucius. Because you are not the real Trurl.
Klapaucius. I had Trurl’s machine make you. And tonight your head comes off, to serve as my bootjack.
THE CLAIM
Trurl. You monster!
Narrator. Klapaucius stood up, and this time he lifted a great club in both hands.
Trurl. Wait! Stop! Listen to me!
Klapaucius. What could you possibly say that would save your head?
Trurl. I am the real Trurl! I hid inside the machine, and had it carry me here.
Trurl. I only wanted to see what you were building, behind your shut doors and your curtains.
THE PROOF
Klapaucius. Nonsense, and not even clever nonsense. I can see straight through you.
Klapaucius. A machine that can make a number five screw can certainly make you.
Trurl. I packed all of that in its belly beforehand! It was easy to guess what you would need!
Klapaucius. So my good friend Trurl is a common sneak? I will never believe it. Take that!
Narrator. He walloped him for slandering his friend, and walloped him again, and again, until his arm gave out.
Klapaucius. Now I will have a little nap. Don’t worry. I will be back.
Narrator. Soon his snoring carried down into the cellar. Trurl wriggled out of the knots, crept up to the machine and climbed into it, and it galloped away for home.
Narrator. Klapaucius watched from his bedroom window, with a hand pressed over his mouth so he would not laugh out loud.
THE MORNING
Narrator. Next day Klapaucius called on Trurl. A gloomy, silent Trurl opened the door. Even in the dark the signs showed: scratches painted over, dents hammered flat.
Klapaucius. Why so glum? I have come to thank you for the present. A pity it ran away while I was asleep.
Trurl. You abused my gift. The machine has told me all of it. You had it make me, the copy of me, I mean, and beat it in your cellar.
Klapaucius. Why so cross? Yes, I had it make a copy, a perfect one. A poke or two, to check the workmanship.
Klapaucius. It even claimed to be you, and called your gift a low trick. So I thrashed it, for your honor.
Klapaucius. It was very like you. Clever, too.
THE BOLTS
Klapaucius. Oh, one more thing. What became of the artificial Trurl? May I have a look at it?
Trurl. It was wild with rage. It meant to ambush you at the mountain pass. It ran off into the dark to build traps.
Trurl. So, for the sake of our old friendship,
Trurl. I had to take it apart.
Narrator. He nudged some nuts and bolts lying on the floor with the toe of his shoe, and sighed.
Narrator. Then they shook hands, and parted as the best of friends.
THE MEDAL
Narrator. From then on Trurl told everyone how the copy had lied so cleverly, and how the real Trurl took it apart to protect his friend.
Narrator. The story reached the royal court, though not long before he had been called the builder of the stupidest computer in the world.
The King. To Trurl, our Order of the Great Parallax.
Klapaucius. What? I saw through his little game. I beat him so soundly that he had to creep home in the dark and patch himself up.
Klapaucius. And for that they give him a medal.
Narrator. Furious, Klapaucius went home, locked the door, and pulled down the blinds.
Narrator. He too had been building a machine to grant every wish. Trurl had simply finished first.