Quantum Physics for Dogs Preview

We’re out for a walk, when the dog spots a squirrel up ahead and takes off in pursuit. The squirrel flees into a yard and dodges around a small ornamental maple. Emmy doesn’t alter her course in the slightest, and just before she slams into the tree, I pull her up short.

“What’d you do that for?” she asks, indignantly.

“What do you mean? You were about to run into a tree, and I stopped you.”

“No I wasn’t.” She looks off after the squirrel, now safely up a bigger tree on the other side of the yard. “Because of quantum.”

We start walking again. “OK, you’re going to have to explain that,” I say.

“Well, I have this plan,” she says. “You know how when I chase the bunnies in the back yard, when I run to the right of the pond, they go left, and get away?”


“And when I run to the left of the pond, they go right, and get away?”


“Well, I’ve thought of a new way to run, so they can’t escape.”

“What, right through the middle of the pond?” It’s only about eight inches deep and a couple of feet across.

“No, silly. I’m going to go both ways. I’ll trap the bunnies between me.”


Because I keep getting odd looks when I describe my book project at this meeting, I whipped up a pdf version of chapter one, so I can point people to it and give them a feel for what it’s like. This is just the latest draft version of Chapter 1, saved as a PDF.

Important caveats: this is not a final version, and I’m putting it up here for demonstration purposes only. It’s subject to change dramatically before it gets close to publication. It’s also subject to disappearing entirely, if I decide to take it down so as not to spoil things. But for the moment, at least, here’s the first chapter, on Particle-Wave Duality.

The snippet above is just a teaser from the dog dialogue that opens the chapter. It’s followed by a longer explanation aimed at human readers, with occasional interjections from the dog. The conceit is that she’s reading along as I go through the draft, and pointing out spots where I didn’t provide enough information to answer all her questions.

I hope you enjoy it, and I hope this gives a clearer picture of what’s going on than the elevator pitch that keeps getting me sideways looks…


  1. #1 IBY
    September 10, 2008

    Man, stupid memory error crap. Now I can’t read it.

  2. #2 Chris Granade
    September 10, 2008

    That’s a wonderful chapter you posted. Thanks for sharing that with us readers. Even though I’m far enough in physics that I’m not really the target audience, I’ll probably buy a copy to lend to people when they ask what I study. Oh, and because the dogtalk is incredibly cute.

  3. #3 Ian Durham
    September 10, 2008

    I was reading the beginning of the post and, being familiar with your conversations with your dog, was just about to suggest you write a book…

  4. #4 The Ridger
    September 10, 2008

    Oh, nice. Now I know I’ll buy several.

  5. #5 IBY
    September 12, 2008

    I managed to read the chapter, and it is really nice! I also like the dog dialogue. :) The way the dog puts quantum mechanic, if quantum mechanic effect would have existed in the macro level, it sounds awesome. Imagine, a dog refracting around the tree. ^_^

  6. #6 Jonathan Vos Post
    September 13, 2008

    Dogs do refract around trees. Assuming that the tree’s radius is roughly the same as the Compton wavelength of the dog = h/mc where
    h is the Planck constant,
    m is the dog’s rest mass,
    c is the speed of light.

    Slightly rephrasing Wikipedia:

    The Compton wavelength can be thought of as a fundamental limitation on measuring the position of a dog, taking quantum mechanics and special relativity into account. This depends on the mass m of the dog. To see this, note that we can measure the position of a dog by bouncing light off it — but measuring the position accurately requires light of short wavelength. Light with a short wavelength consists of photons of high energy. If the energy of these photons exceeds mc^2, when one hits the dog whose position is being measured, the collision may have enough energy to create a new dog of the same type. This renders moot the question of the original dog’s location.

    Now, how fast can a rabbit run, compared to c? And what if your dog trees Schrodinger’s cat?

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