Sunday, May 10, 2009

Sometimes Advil's not enough...

As someone who has tried vigorously to make it all the way through "A Brief History of Time" on several occasions, and has little understanding to show for it, the new ideas floating around quantum physics don't seem to fit into my skull.
Quantum physics is the study of the very small -- atoms, photons and other particles. Unlike the cause-and-effect of our everyday physical world, subatomic particles defy common sense and behave in wacky ways. That includes the fact that a photon, which is a particle of light, exists in a haze of multiple behaviors. They spin in many ways, such as "up" or "down," at the same time. Even trickier, it's only when you take a peek -- by measuring it -- that the photon fixes into a particular state of spin.
Stranger still is entanglement. When two photons get "entangled" they behave like a joint entity. Even when they're miles apart, if the spin of one particle is changed, the spin of the other instantly changes, too. This direct influence of one object on another distant one is called non-locality.

Last year, Dr. Gisin and colleagues at Geneva University described how they had entangled a pair of photons in their lab. They then fired them, along fiber-optic cables of exactly equal length, to two Swiss villages some 11 miles apart.
During the journey, when one photon switched to a slightly higher energy level, its twin instantly switched to a slightly lower one. But the sum of the energies stayed constant, proving that the photons remained entangled.
More important, the team couldn't detect any time difference in the changes. "If there was any communication, it would have to have been at least 10,000 times the speed of light," says Dr. Gisin. "Because this is such an unlikely speed, the conclusion is there couldn't have been communication and so there is non-locality." [More]
Say what?

 Which leads me to situations like this:

Pass the medicinal gin, please.

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