illuminating science

After watching What the bleep?! the other day, I’ve been thinking about something that they said in the movie, i.e., that quantum mechanics is “utterly astounding” or “magical”. They really pushed the connection that because quantum mechanics is mystical, and mysticism is, well, mystical, that the two must be related. That quantum mechanics is astounding is probably up to personal opinion (and how long you’ve been studying it!) but should it be considered magical or mystical? I would argue that quantum mechanics is just unintuitive and unfamiliar, and that once you’ve learned about it and understand it a bit more it’s not magical. It’s a little hard to exactly put into words what I’m saying here, and were it not for the recurring nightmares I should probably see the movie again, but I hope you get the gist.

What makes QM seem mystical? Things like quantum tunneling (the ability to pass through barriers), superpositions (being in two places at once) or entanglement (”spooky action at a distance”, where the state (or fate) of two objects becomes linked, no matter how far apart they are). These are all strange and bizarre, no doubt, and are literally straight out of the pages of science fiction. Yet physicists claim that these are the underlying laws of the universe - something that many people have a hard time believing.

I think the point is, though, that these effects aren’t “weird” or “mystical” - they’re just unfamiliar since they don’t apply to world on the scale where we usually interact. There are other laws of physics that we take for granted, even though they predict equally astounding things - take gravity for example. Imagine that you’d lived your whole life on a space ship in deep space, far away from any stars or planets. Your whole life has been in zero-G, and you’ve never even heard of gravity. Then, one day, your captain brings you news of this strange theory of gravity which says “every object attracts every other object”. This seems pretty strange and unlikely - after all, objects don’t clump together as it floats around the ship, and nor do you stick to the walls. And why should you? Why should objects attract at all? It would probably sound intuitive, and probably flat out wrong. But if you studied the theory close enough, you’d realise that it just never mattered to you before because you’d never been near anything big enough or worked with anything small enough. If, however, you could go and visit a planet, or carried out some simple but subtle experiments, you’d find that the theory of gravity explains everything very nicely, and you’d probably come to accept it.

Similarly, quantum mechanics makes predictions which are very hard to understand in terms of what we’re used to. But a few simple experiments give you a tantalising hint of the truth, and eventually quantum mechanics becomes, if not intuitive, then at least acceptable. I’ve been at it for a mere six years or so, so I can’t claim to understand quantum mechanics, but things like tunnelling or wave-particle duality don’t freak me out anymore. And I think a part of it, too, is that science shows and books love to make a big thing about how strange quantum mechanics is (”it’s both a particle and a wave! Oooooh!”).

So I’m not sure what the real aim of this meander was - I guess just to point out that the predictions of quantum mechanics aren’t really as bizarre as they’re often made out to be. They’re different, unfamiliar and at times counter-intuitive, but there’s nothing magical about it!