Posted on 02/23/2006 3:58:12 AM PST by S0122017
Quantum computer works best switched off
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)
From issue 2540 of New Scientist magazine, 22 February 2006, page 21
"How about a nice game of chess?"
as a photon might do interference with itself on a double slit as long as we detect where it NOT has gone through, in wich case the interference is not observed ?
this is not a bad explanation: http://en.wikipedia.org/wiki/Quantum_Zeno_effect
I have an old broken wrist watch that can do that. . .twice everyday.
http://www.freerepublic.com/focus/f-chat/1582836/posts?page=1,100
Microsoft, are you listening to this?
I am not, therefore I think
I woke up this morning and the dishes still aren't done.
I's amazing, I first understood the concept of quantum-computers when I read "Transit" by Michael Chricton :(
When they get it right there will be no limits for what a computer can do, I think...
Actually if our brains where quantum we would know the articles without even having to read them.
Ha! I've been posting responses to articles without reading them for years! Who needs a quantum computer!
Mark
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.
Knowing something about computer science, I find the above statement to be techno-babble. To be useful, an algorithm (implemented by a program) has to be defined, finite, and repeatable. The description given is none of the above. Just letting a photon richochet around(flirting with the program's components?) for some random period of time, until you get an "answer" is not a program. The above (based on this description) seems neither. It could also be a case of the journalist not understanding the technology.
On the other hand, qunatum computers hold the promise of solving combinatorial problems (like the Traveling Salesmen Problem) instantly. It would render the question, is P=NP?, irrelevant.
There is a very high-level principle that says that something and its opposite can not exist at the same time. Smith can't be alive and dead at the same time.
Any science that claims that a "cat" can be alive and dead at the same time is invalid.
Particle physics is not a true science.
Nothing new... some of my best programs have never run. :-)
I read it twice and I still don't understand. I think it has something to do with "It all depends on what the meaning of 'run' is."
OK Baby Duckling, Turn off the ignition switch and make like your getting out.
Dagwood will be so proud.
"The political analogy might be a kernel of truth and logic getting into a hard leftist's head."
In other words, an impossibility.
Thats a another way of saying yes.
Normal is if you would send the actual particle and allow it to interact with components till you get an answer.
In this case the particle didnt went through but its
you-never-know-where-it-may-be quantum states allowed it to interact with a computer component, which was affected enough to affect something else etc. In the end you got a result without ever letting the particle in the computer.
Now were getting serious. Can any of you explain what this means.
How does the photon KNOW it's being measured?
Mind Boggles, but extremely intrigued!!
You have a good point, if the program was run again it would probably not give the same answer.
However it is still a sort of program. A random number generator can be a program too, aferall.
If i shine a light at you you know youre being examined.
If i shine a light at a particle it may heat up and that change due to interaction with the measuring medium is commonly regered to as 'knowing youre being measured'.
There is no way to measure a particle something without interfering with it. Unless you can guarantee it is in the exact same state after the measurement as before and thats not possible.
Ok, I get that, but I guess I don't see how "it's nature" then interacts with the computer.
Why are we stopping the photon in the first place because it will JUST pass thru and not interact?
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