I Understand the Dead Cat

"So what I told you is True - from a certain point of view..."

- Obi-Wan Kenobi

Larry Gopnik: 

Well, you can't do physics without mathematics, really, can you?

Clive Park: 

If I receive failing grade I lose my scholarship, and feel shame. 

I understand the physics. 

I understand the dead cat.

Larry Gopnik: 

You understand the dead cat? 

But... you... you can't really understand the physics without understanding the math. 

The math tells how it really works. 

That's the real thing; the stories I give you in class are just illustrative; they're like, fables, say, to help give you a picture. 

An imperfect model. 

I mean - even I don't understand the dead cat. 

The math is how it really works.

Clive Park: 

Very difficult... very difficult...

“Oh, well, I’m glad of that,” said Richard, “but what was all that rubbish about cats and quantum mechanics?”

With a sigh Dirk flipped up the lid of the pizza with a single flick of practised fingers. He surveyed the cold round thing with a kind of sadness and then tore off a hunk of it. Pieces of pepperoni and anchovy scattered over his desk.

“I am sure, Richard,” he said, “that you are familiar with the notion of Schrödinger’s Cat,” and he stuffed the larger part of the hunk into his mouth.

“Of course,” said Richard. “Well, reasonably familiar.”

“What is it?” said Dirk through a mouthful.

Richard shifted irritably in his seat. “It’s an illustration,” he said, “of the principle that at a quantum level all events are governed by probabilities—”

“At a quantum level, and therefore at all levels,” interrupted Dirk. “Though at any level higher than the subatomic the cumulative effect of those probabilities is, in the normal course of events, indistinguishable from the effect of hard and fast physical laws. Continue.”

He put some more cold pizza into his face.

Richard reflected that Dirk’s was a face into which too much had already been put. What with that and the amount he talked, the traffic through his mouth was almost incessant. His ears, on the other hand, remained almost totally unused in normal conversation.

It occurred to Richard that if Lamarck had been right and you were to take a line through this behaviour for several generations, the chances were that some radical replumbing of the interior of the skull would eventually take place.

Richard continued, “Not only are quantum level events governed by probabilities, but those probabilities aren’t even resolved into actual events until they are measured. Or to use a phrase that I just heard you use in a rather bizarre context, the act of measurement collapses the probability waveform. Up until that point all the possible courses of action open to, say, an electron, coexist as probability waveforms. Nothing is decided. Until it’s measured.”

Dirk nodded. “More or less,” he said, taking another mouthful. “But what of the cat?”

Richard decided that there was only one way to avoid having to watch Dirk eat his way through all the rest of the pizza, and that was to eat the rest himself. He rolled it up and took a token nibble off the end. It was rather good. He took another bite.

Dirk watched this with startled dismay.

“So,” said Richard, “the idea behind Schrödinger’s Cat was to try and imagine a way in which the effects of probabilistic behaviour at a quantum level could be considered at a macroscopic level. Or let’s say an everyday level.”

“Yes, let’s,” said Dirk, regarding the rest of the pizza with a stricken look. Richard took another bite and continued cheerfully.

“So you imagine that you take a cat and put it in a box that you can seal completely. Also in the box you put a small lump of radioactive material, and a phial of poison gas. You arrange it so that within a given period of time there is an exactly fifty-fifty chance that an atom in the radioactive lump will decay and emit an electron. If it does decay then it triggers the release of the gas and kills the cat. If it doesn’t, the cat lives. Fifty-fifty. Depending on the fifty-fifty chance that a single atom does or does not decay.

“The point as I understand it is this: since the decay of a single atom is a quantum level event that wouldn’t be resolved either way until it was observed, and since you don’t make the observation until you open the box and see whether the cat is alive or dead, then there’s a rather extraordinary consequence.

“Until you do open the box the cat itself exists in an indeterminate state. The possibility that it is alive, and the possibility that it is dead, are two different waveforms superimposed on each other inside the box. Schrödinger put forward this idea to illustrate what he thought was absurd about quantum theory.”

Dirk got up and padded over to the window, probably not so much for the meagre view it afforded over an old warehouse on which an alternative comedian was lavishing his vast lager commercial fees developing into luxury apartments, as for the lack of view it afforded of the last piece of pizza disappearing.

“Exactly,” said Dirk, “bravo!”

“But what’s all that got to do with this—this Detective Agency?”

“Oh, that. Well, some researchers were once conducting such an experiment, but when they opened up the box, the cat was neither alive nor dead but was in fact completely missing, and they called me in to investigate. 

I was able to deduce that nothing very dramatic had happened. 

The cat had merely got fed up with being repeatedly locked up in a box and occasionally gassed and had taken the first opportunity to hoof it through the window. 

It was for me the work of a moment to set a saucer of milk by the window and call ‘Bernice’ in an enticing voice — the cat’s name was Bernice, you understand—”

“Now, wait a minute—” said Richard.

“—and the cat was soon restored. A simple enough matter, but it seemed to create quite an impression in certain circles, and soon one thing led to another as they do and it all culminated in the thriving career you see before you.”

“Wait a minute, wait a minute,” insisted Richard, slapping the table.

“Yes?” enquired Dirk innocently.

“Now, what are you talking about, Dirk?”

“You have a problem with what I have told you?”

“Well, I hardly know where to begin,” protested Richard. “All right. You said that some people were performing the experiment. That’s nonsense. Schrödinger’s Cat isn’t a real experiment. It’s just an illustration for arguing about the idea. It’s not something you’d actually do.”

Dirk was watching him with odd attention.

“Oh, really?” he said at last. “And why not?”

“Well, there’s nothing you can test. The whole point of the idea is to think about what happens before you make your observation. You can’t know what’s going on inside the box without looking, and the very instant you look the wave packet collapses and the probabilities resolve. It’s self-defeating. It’s completely purposeless.”

“You are, of course, perfectly correct as far as you go,” replied Dirk, returning to his seat. He drew a cigarette out of the packet, tapped it several times on the desk, and leant across the desk and pointed the filter at Richard.

“But think about this,” he continued. “Supposing you were to introduce a psychic, someone with clairvoyant powers, into the experiment—someone who is able to divine what state of health the cat is in without opening the box. Someone who has, perhaps, a certain eerie sympathy with cats. What then? Might that furnish us with an additional insight into the problem of quantum physics?”

“Is that what they wanted to do?”

“It’s what they did.”

“Dirk, this is complete nonsense.”

Dirk raised his eyebrows challengingly.

“All right, all right,” said Richard, holding up his palms, “let’s just follow it through. Even if I accepted—which I don’t for one second—that there was any basis at all for clairvoyance, it wouldn’t alter the fundamental undoableness of the experiment. As I said, the whole thing turns on what happens inside the box before it’s observed. It doesn’t matter how you observe it, whether you look into the box with your eyes or—well, with your mind, if you insist. If clairvoyance works, then it’s just another way of looking into the box, and if it doesn’t then of course it’s irrelevant.”

“It might depend, of course, on the view you take of clairvoyance…”

“Oh yes? And what view do you take of clairvoyance? I should be very interested to know, given your history.”

Dirk tapped the cigarette on the desk again and looked narrowly at Richard.

There was a deep and prolonged silence, disturbed only by the sound of distant crying in French.

“I take the view I have always taken,” said Dirk eventually.

“Which is?”

“That I am not clairvoyant.”

“Really,” said Richard. “Then what about the exam papers?”

The eyes of Dirk Gently darkened at the mention of this subject.

“A coincidence,” he said, in a low, savage voice, “a strange and chilling coincidence, but none the less a coincidence. One, I might add, which caused me to spend a considerable time in prison. Coincidences can be frightening and dangerous things.”

Dirk gave Richard another of his long appraising looks.

“I have been watching you carefully,” he said. “You seem to be extremely relaxed for a man in your position.”

This seemed to Richard to be an odd remark, and he tried to make sense of it for a moment. Then the light dawned, and it was an aggravating light.

“Good heavens,” he said, “he hasn’t got to you as well, has he?”

This remark seemed to puzzle Dirk in return.

“Who hasn’t got to me?” he said.

“Gordon. No, obviously not. Gordon Way. He has this habit of trying to get other people to bring pressure on me to get on with what he sees as important work. I thought for a moment—oh, never mind. What did you mean, then?”

“Ah. Gordon Way has this habit, has he?"

“Yes. I don’t like it. Why?”

Dirk looked long and hard at Richard, tapping a pencil lightly on the desk.

Then he leaned back in his chair and said as follows: “The body of Gordon Way was discovered before dawn this morning. He had been shot, strangled, and then his house was set on fire. Police are working on the theory that he was not actually shot in the house because no shotgun pellets were discovered there other than those in the body.

“However, pellets were found near to Mr Way’s Mercedes 500 SEC, which was found abandoned about three miles from his house. This suggests that the body was moved after the murder. Furthermore the doctor who examined the body is of the opinion that Mr Way was in fact strangled after he was shot, which seems to suggest a certain confusion in the mind of the killer.

“By a startling coincidence it appears that the police last night had occasion to interview a very confused-seeming gentleman who said that he was suffering from some kind of guilt complex about having just run over his employer.

“That man was a Mr Richard MacDuff, and his employer was the deceased, Mr Gordon Way. It has further been suggested that Mr Richard MacDuff is one of the two people most likely to benefit from Mr Way’s death, since WayForward Technologies would almost certainly pass at least partly into his hands. The other person is his only living relative, Miss Susan Way, into whose flat Mr Richard MacDuff was observed to break last night. The police don’t know that bit, of course. Nor, if we can help it, will they. However, any relationship between the two of them will naturally come under close scrutiny. The news reports on the radio say that they are urgently seeking Mr MacDuff, who they believe will be able to help them with their enquiries, but the tone of voice says that he’s clearly guilty as hell.

My scale of charges is as follows: two hundred pounds a day, plus expenses. Expenses are not negotiable and will sometimes strike those who do not understand these matters as somewhat tangential. They are all necessary and are, as I say, not negotiable.

 Am I hired?”

“Sorry,” said Richard, nodding slightly. “Would you start that again?”

Excerpt From: Adams, Douglas. 

“Dirk Gently's Holistic Detective Agency.”