From New Scientist :
Even for the crazy world of quantum mechanics, this one is twisted. A quantum computer program has produced an answer without actually running.
The idea behind the feat, first proposed in 1998, is to put a quantum computer into a “superposition”, a state in which it is both running and not running. It is as if you asked Schrödinger's cat to hit "Run".
With the right set-up, the theory suggested, the computer would sometimes get an answer out of the computer even though the program did not run. And now researchers from the University of Illinois at Urbana-Champaign have improved on the original design and built a non-running quantum computer that really works.
They send a photon into a system of mirrors and other optical devices, which included a set of components that run a simple database search by changing the properties of the photon.
The new design includes a quantum trick called the Zeno effect. Repeated measurements stop the photon from entering the actual program, but allow its quantum nature to flirt with the program's components - so it can become gradually altered even though it never actually passes through.
"It is very bizarre that you know your computer has not run but you also know what the answer is," says team member Onur Hosten.
This scheme could have an advantage over straightforward quantum computing. "A non-running computer produces fewer errors," says Hosten. That sentiment should have technophobes nodding enthusiastically.
Journal reference: Nature (vol 439, p 949)
The Zeno effect? How paradoxical.
It's said "a watched pot never boils". Well, in the world of quantum physics, watch it often enough, and it can't. Every time you look at an unstable particle, you collapse its wavefunction for a bit.
I'm not sure of the large-scale ramifications of this one, but it proves once more that Reality, if you look very closely, is not so much Real as Surreal.
No comments:
Post a Comment
Anonymous commenters - please add a signature (doesn't have to be your real name) on each post of yours. Anne O'Namus, Norm D. Ploom, Angry from Kent, Demosthenes, or even your real initials, it doesn't matter.
Commenters are expected to be polite to each other, but the same standard doesn't apply to comments regarding me.
Australian commenters are very very strongly advised to publish anonymously. Sydney alone has more defamation actions than the entire USA and UK. Nearly double that of the UK in fact.
As Google does not reliably inform me that a comment has been posted, and I have no control over first publication, I assert that all comments are innocently disseminated under the NSW DEFAMATION ACT 2005 - SECT 32 and similar acts.