Teleportation of Toddler Toys

Today is the official release date for the paperback edition of How to Teach Physics to Your Dog, so I wanted to write up something cool about quantum physics to mark the occasion. I looked around the house for inspiration, and most of what we have lying around the house is SteelyKid’s toys. Thus, I will now explain the physics of quantum teleportation using SteelyKid’s toys:

i-e5180a31fe9ec0c7c9bc1831e14ede84-icon_emmy_wake.jpg“Wait, wait, wait… You’re not seriously planning to explain something quantum without me, are you?”

“I could hardly expect to get away with that, could I. No, I’m happy to have your contributions– the book is about talking physics with you, after all. Just break in if you have something to add, and I’ll put it into the blog post.”

When I have something to add, you mean. Because I’m going to have stuff to add, you know.”

“Oh, I know it…”

The phenomenon known as “quantum teleportation” (a slightly unfortunate name) involves using quantum entanglement– the strange phenomenon Einstein called “spukhafte fernwirkung” or “spooky action at a distance”– to transmit the state of a quantum system from one place to another without disturbing it. Explaining teleportation thus involves both a sender and a receiver of the quantum state, who are traditionally referred to as “Alice” and “Bob.” Since SteelyKid doesn’t have many anthropomorphic toys, though, we’ll use these two:


Appa and Bertha the Big Bear (It’s a little disconcerting, by the way, to watch SteelyKid playing with these two, and remember that not all that long ago, she was significantly smaller than either of them…).

So, the scenario is this: Appa has a quantum object, whose exact state he doesn’t know, so it is in some superposition of all the available states at the same time. This could be anything– an atom with two possible states, an electron spin, a polarized photon. We’ll represent Appa’s unknown state by this little brown-and-white dog:


And he wants to transmit this state to Bertha, who is a long distance away:


So, how can he send this state to Bertha and make sure she gets exactly the state that he starts with?

i-d0038e7c164862bba3479eef3a5ee03e-icon_emmy_stare.jpg“What do you mean, how can he send it to her? He just makes another one just like the one he’s got, and sends her the copy. End of experiment.”

“That does seem like the obvious course of action, but in fact, it’s not possible. There’s a mathematical rule about quantum physics, helpfully called the ‘no-cloning theorem,’ that says it’s impossible to make a perfect copy of a single quantum state unless you already know something about the state.”


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The Physics of the Imbecile: Chopra Interviews Kaku

I don’t remember who pointed me at this transcript of Deepak Chopra interviewing Michio Kaku, but if I remember who it was, I fully intend to hate them.

DC: Is our conversation affecting something in another galaxy right now?

MK: In principle. What we’re talking about right is affecting another galaxy far, far beyond the Milky Way Galaxy. Now when the Big Bang took place we think that most of the matter probably was vibrating in unison.

DC: So it was already correlated?

MK: It was already correlated. We call this coherence or correlation. As the universe expanded, we’re still correlated, we’re still bound by these invisible webs. You can’t see them. The book Physics of the Impossible is being filmed for the Science Channel and we actually filmed this quantum entanglement.

DC: You actually demonstrated this?

MK: We actually demonstrated it right on TV cameras. We went to the University of Maryland outside Baltimore and we showed an atom being teleported right across the room. You can actually see two chambers, an atom in one being zapped across the room. A TV screen shows the blip whenever an atom is being teleported and this is non-local matter.

DC: That means going from here to there without the space in between?

MK: That’s right it just disappears and reappears to someplace else.


The whole thing is like this. It’s just brimful of gibberish. I mean, I expect Chopra to sound like a character from Star Trek, that’s his shtick, but Kaku claims to be a scientist. He’s on every other show on the goddamn Science Channel, and here he is spouting New Age twaddle and grossly misrepresenting good science.

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