Twin telepathy

Although the evidence for telepathy has been coming in regularly since the founding in 1882 of the Society for Psychical Research -overall probability of chance in all of the published controlled experiments being of the order of one in billions - many remain unconvinced. Some refuse to admit even the possibility of telepathy, while more reasonable sceptics prefer to suspend judgment until there is not only unmistakable evidence for it and a theory explaining how it works. We may now have both.

We have had the statistical evidence for some time, and we now have the visible evidence, produced by an easily repeatable experiment. As for the theory, this too has been around for nearly a hundred years though many are still unaware of it. It's called quantum theory, and while nobody seems to understand it, there is general agreement in the scientific community that it works and can be put to practical use.

One feature of it is "nonlocality", whereby two particles - such as photons - that form a simultaneously generated or "entangled" pair act as if they remain in contact even when separated. Science writers often compare such particles to identical twins, who begin their lives literally entangled.

"Non-local behaviour has been proved to occur by real experiments," writes John Gribbin in his book Schrodinger's Kittens (1995). It is as if the two quantum entities "remain tangled up with one another for ever, so that when one is prodded the other twitches, instantaneously, no matter how far apart they are."