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Tuesday, 27 October, 1998, 10:53 GMT
Not quite beam me up Scotty!
Nobody is likely to say
Nobody is likely to say "beam me up Scotty" for a long time - if ever
By Our Science Editor David Whitehouse

Let's be clear. There has been no breakthrough in building a Star Trek style 'transporter'. But what has got some scientists buzzing is the demonstration of a very weird effect of the sub-atomic world.

It is called 'entanglement' and it would be true to say that nobody really understands it.

The world of the very small - what physicists call the 'quantum world' - is extremely puzzling.

Atoms and the particles that comprise them, as well as light and energy, behave in strange ways, none more so than the phenomenon of entanglement.

An intriguing demonstration has been carried out at the California Institute of Technology and Aarhus University in Denmark.

In the quantum world normal rules about matter and energy do not apply. Everything, including space and time itself, comes in lumps or quanta.

Entanglement occurs when two photons of light have related properties even when they are far apart. Do something to one photon and instantaneously the other will change.

In a sense this appears to violate one of the golden rules of physics - that no information can be transmitted faster than the speed of light.

In reality most scientists believe that entanglement may not allow super-light information transfer.

Nonetheless it is something that has mystified researchers for decades. Albert Einstein called it "spooky action at a distance."

The scientists used two entangled beams to carry information about the state of a third beam.

In a sense they have created a replica of the original light beam. What has been transmitted from one light beam to another is information that was used to recreate the original beam.

Last year a team of Austrian physicists followed by a team in Rome demonstrated a similar thing with single photons rather than full light beams.

At the moment what has been achieved is an interesting physics experiment and is far removed from any practical uses though it may someday find computer applications.

Suggestions that the technique could be the basis for a 'teleporter' to transport a bacterium is wild speculation.

The amount of information needed to describe a bacterium or a human being is far beyond anything that could be transmitted at the moment or in the foreseeable future.

There is also the problem that a transporter, if it could be built, would not send a person from A to B.

Rather it would destroy the person at point A and make a copy of him or her at point B.

Given that, it would seem unlikely that there would be any volunteers.

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