Wednesday, December 13, 2006
Doggerel #17.1: "Quantum" (Take Two)
This updated edition of "Doggerel" brought to you by Infophile.
Welcome back to "Doggerel," where Bronze Dog rambles on about words and phrases that are misused, abused, or just plain meaningless. This week’s going to be a bit different, though. We’re returning to a subject that presents a most interesting problem: Quantum Mechanics. Richard Feynman explains it best:
“I think I can safely say that no one understands quantum mechanics.”
And there’s the problem: Bronze Dog isn’t “no one,” so he can’t come out here and explain it. I, on the other hand, am different. In order to facilitate the help I’ve given the Canadian Special Forces (Never heard of them? That’s how good they are), the Canadian government has officially registered “no one” as one of my identities. This means that when someone comes up with a code that “no one” can crack, I can crack it. Or maybe if “no one” can tell the difference between butter and I Can’t Believe it’s Not Butter, I can. I also understand Quantum Mechanics (henceforth “QM”).
The big problem with QM is that it’s in many ways counter-intuitive. Effects are somewhat non-local. Conservation of Energy can be temporarily ignored under the right circumstances. Particles act like both particles and waves at the same time. The results of experiments aren’t deterministic, but instead based on probabilities. And with all this, scientists still can’t agree on what causes all of this odd behavior.
There are two key ingredients here, QM being weird and scientists not knowing everything about it, which make “quantum” a very appealing word for woos to use. They figure that it gives them carte blanche if they explain any weird effect away as being “quantum.” It’s not just an “energy field,” it’s a “quantum energy field!”
Of course, they don’t understand it themselves most of the time, so in the end, it’s no better than hand-waving it away as “magic.” In fact, it’s worth noting that in Terry Pratchett’s Discworld novels, where magic is a well-understood force of nature, the use of the term “quantum” in explaining what counts for woo in that universe plays exactly the same role that the term “magic” does in ours.
The logic the woos use to defend their claims boils down to asking how, if scientists don’t understand Quantum Mechanics, they can claim the woos are wrong about it? It’s simple, really. Scientists are confused about what causes all of this, not what can happen. The possible events in QM are all well-defined, and the calculations of probabilities are done deterministically.
Now, there’s one particular phenomenon of QM, which the woos (particularly “psychics”) seem to love, that bears special mention here: Entanglement. In the simplest sense, entanglement means that there’s a correlation between two different observables. Remember that in general, measurements in QM have random outcomes. When two particles are entangled, measuring just one of them will still have a random outcome. But if you measure both at the same time, they’re outcomes will be related somehow – they might both always have the same outcome, always opposite outcomes, or simply tend more towards one of these extremes.
These effects occur regardless of distance between the two particles, so it seems like there’s some information traveling from one to the other, telling it what it should resolve as, at faster than lightspeed. This apparent transfer of information has made entanglement seem like a good way to explain faster-than-light communication for bad Science Fiction writers. Some woos also use it to explain telepathy by claiming the psychic’s thoughts become entangled with those of the subject.
It doesn’t quite work that way, however. Let’s go with a metaphor for entanglement: two magical entangled coins. These coins have the properties that their flips are always perfectly random, and if they’re both flipped simultaneously, they’ll always both come up the same way. So, let’s say that we have a human colony many lightyears away we wish to communicate with. We keep one coin with us, and the people going over there bring one coin with them.
Now, how would we use these coins to communicate with them? You could try to receive data by flipping your own coin, but all you know from it is that if someone’s flipping it at the colony, they’re getting the same results. You could try to force the coin to come up one way, in hopes of sending binary information, but the first property of the coin prevents this: Its flips are always random, no matter what you try to do. In the end, all you can possibly get from this coin is logical inference about the other coin. There is an instantaneous transmission of information between the two, but the data that’s transmitted is completely random and can’t be forced.
The way psychic apologists use entanglement requires a different rebuttal. They can actually get around the above restriction if they claim they claim that conscious thoughts are generated in part by the random outcomes of quantum processes (which some bona fide scientists are theorizing). In this case, if part of the psychic’s mind is entangled with the subject’s mind, the same thoughts will be randomly generated in both. The problem in this case is that there’s no reason the two minds should have become entangled in the first place. Entanglement between two particles happens due to a close, quantum-scale interaction between the two. You can’t just magically turn on entanglement with someone who’s far away from you.