Teleportation: Talk the Talk

How to sound like an expert and talk confidently about teleportation.

Everybody knows about teleportation. But many people’s knowledge is derived entirely from sci-fi books and movies, not from any real science. You can often spot these individuals by their tendency to refer to teleportation as something primarily done by humans (or aliens), and done by them of their own volition, in the same way you might decide to, say, stand up, or make a phone call.

Physicists use a somewhat different vocabulary when discussing teleportation (even though many of them are active sci-fi fans when they’re away from the lab, so can speak both languages). Here are a few pointers.

Where does the word “teleportation” come from?

Zero points if your answer is The Twilight Zone. The strictly accurate answer for people with large foreheads is that it derives from two words: telos — from the Greek, meaning “end” or “endpoint”, and portare from the Latin, meaning “to carry”. So teleportation means “to carry to an endpoint”.

You’ll have come across other phrases for the act of teleportation in sci-fi — and various means of carrying it out. The Star Trek device was called a “matter transference beam”, while on Blake’s 7 an exotic alloy called Aquatar was required for teleportation. Meanwhile, in the 1970s TV show The Tomorrow People, the act was known as “jaunting” and the main piece of equipment needed was a belt with a groovy geometric design on the buckle.

So, there are many interpretations, but the essential characteristic of teleportation though is that it is instantaneous and has no regard for distance between origin and destination.

Rumours of teleportation have been greatly exaggerated

Teleportation in the usual sense has sadly not yet been demonstrated, despite various stories that have appeared in the press. If anyone insists that it has, you can rebuff them with three reasons why, as far as current modern understanding goes, it’s impracticable to teleport anything even remotely like a human being.

If you were planning to break down the constituent atoms of the teleportee object in Location A, then transport that raw mass as energy to Location B, for recreation back into matter (using Einstein’s E=mc^2 equation, naturally), the amount of energy you’d need would be vast — comparable to millions of megatons of atomic blast. So, not feasible really.

You might instead think of trying to send the information about the make-up of the object to the new location, so that a replica could be created using that information. But the amount of information you’d need would be enormous — many times more than all the words in all the books ever written in the world. So, again, not a viable process.

And perhaps most conclusive of all: quantum physics prevents teleportation by information transfer, as a matter of principle. (More details on this coming up in a moment.)

Quantum teleportation

Although teleportation has not been carried out , “quantum teleportation” has.

This is certainly a very different thing from the matter transference beam, but it’s nonetheless creating a lot of excitement in the world of physics.

But wait! Did every muscle in your body tense slightly as you read the word “quantum”? It does tend to have that effect on people. But if so, breathe deeply … relax.

The best-kept secret about quantum physics is that, contrary to popular perception, you don’t have to be Albert Einstein or Neils Bohr to understand the basic principles — anyone can. Sure, it can become supremely complex if you study it at a high level, but that’s true of any subject. The only challenging — or should we say exhilarating — thing about it is the fact that it requires a whole new way of thinking.

“Quantum” refers to the world we see when we look at the world on an extremely small scale. And in this world, individual particles such as photons, electrons, protons and other so-called “sub-atomic” particles obey the laws of quantum physics. These laws, strangely enough, are quite different from the rules of physics which govern objects in our everyday world. And that’s the important thing to take onboard — a different set of rules apply.

Rather wacky rules, admittedly.

For example, get your head round this one: objects in the quantum zone can be both waves and particles at the same time. And furthermore those same objects are changed, simply by the experience of being observed or measured. Seems crazy to most non-physicists. But then, fish breathe water and cute babies can grow up into evil politicians, so there are many equally ‘strange’ things out there which we just accept after a while.

And getting back to why teleportation of everyday objects is not possible, the reason is that it would flout one of the central laws of quantum physics, Heisenberg’s Uncertainty Principle. What this rule states, is that you cannot know both the position and the velocity of a particle at the same time. You just can’t, it’s not possible. And therefore, you could never collate all the information you would need about the atoms in your object to be able to teleport it elsewhere.

So sci-fi style teleportation is a no-go. But this other activity, known as quantum teleportation is. Or at least, the carrying-of-information-to-an-endpoint-instantaneously is.

This quantum teleportation or information transfer can occur when you have two particles which are, to use the jargon, “entangled”.

The two particles look as though they are quite separate — but in fact they are one quantum ’system’ and anything that is done to one part of it, is instantaneously felt by the rest of the system, no matter how far away it may be. Like psychic twins.

You may wonder what use anything on this minute scale is to anyone concerned with the “real” world, but the answer is: it may prove to be extremely useful.

Superfast information delivery is the future in any case, and there are many practical applications being researched for quantum teleportation at the moment. The present front runner is ’quantum computing’. If this takes off, it could make the present Internet look as dated as Stephenson’s Rocket… and mean $$$$$ for all involved.

So, watch this space. And never mock the humble sub-atomic particle again!

This article was previously published in September 2005 on OpenLearn. You should subscribe to our newsletter for more free courses, articles, games and videos.