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Programmable Quantum Computer Created
An anonymous reader writes "A team at NIST (the National Institute of Standards and Technology) used berylium ions, lasers and electrodes to develop a quantum system that performed 160 randomly chosen routines. Other quantum systems to date have only been able to perform single, prescribed tasks. Other researchers say the system could be scaled up. 'The researchers ran each program 900 times. On average, the quantum computer operated accurately 79 percent of the time, the team reported in their paper.'"
My dice are 100% accurate. I ask them for a random number, and every time that is what they return.
So is that 21% of the time is was both correct and incorrect ?
That's correct and the other 79% of the time the cat died.
It's NOT me! It's the meds! I'm on 1000mg of Fukitol.
On average, the quantum computer operated accurately 79 percent of the time,
Well, its better then anything Microsoft can come up with...I'll take 10!
In some alternate universe, there's a guy who is riding a bus, a thought pops into his head, "Pick a number between 1 and 100. Now, add 3. Now, divide by 13...". 99% of the time, he does the problem in his head, 79% of the time he finishes it. 1% of the time, he says, "Screw it". 100% of the time, he wonders where the hell these things are coming from and decides to check himself into the nearest mental ward.
Quantum computing is screwing up someone's day.
Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong fix.
79% accurate. That's pretty useless.
Not useless at all, just have it solve the same problem 5 or 15 times and go with the answer that it gives most often. Plus, for some problems it's much easier to verify an answer than to come up with it -- for those problems, just pair it with a normal computer to check the answers, and keep trying until it says the answer is right.
79% accurate. That's pretty useless. I've got a pair of dice that can do just as badly.
You may be interested in purchasing this chip I have here. It has a very nice fdiv routine. Since we're so good friends, I'll give you a 100.00001353% discount.
I'm curious how they could possibly know that it operated correctly 79% of the time, since the underlying quantum state isn't observable. You could say it produced the 'correct' results 79% of the time, but that's not the same as saying it operated correctly 79% of the time; it's very possible for a quantum computer to operate incorrectly and still produce the right result, through sheer random chance.
I suppose I could read the paper.
Can you imagine the accuracy of a Beowulf cluster of that?
Plain old sigh.
So in the other universe 21% of the time cats die. I knew this universe was violent!
Here be signatures
That's TOTALLY moronic. That's like saying "get 5 or 15 people to guess your birthday and go with the answer that it gives most often."
Are people accurate 79% of the time? In the examples you gave? Then no, it's not like that at all.
How stupid can you get?
Many thanks for demonstrating!
No, it's actually a perfectly reasonable idea. Consider running the device (n+m) times. The probability of it being right n times and wrong m times is given by:
P(n,m) = (n+m)!/n!/m! 0.79^n 0.21^m
Now consider the probability of it being right (majority has the right answer) out of 2n+1 trials. This is the given by:
S(n) = sum( P(n+1+i,n-i), i=0..n )
This can be simplied to a closed form using Legendre and gamma functions, but that's kind of messy and it's far easier to just plug in values and do the summation. As it turns out, doing the experiment 15 times and taking the majority (plugging 7 into S(n)) will give you the correct answer 99.4% of the time. Doing things 35 times gets you to five nines of accuracy... completely reasonable in my books.
79% accurate. That's pretty useless.
Not useless at all, just have it solve the same problem 5 or 15 times and go with the answer that it gives most often. Plus, for some problems it's much easier to verify an answer than to come up with it -- for those problems, just pair it with a normal computer to check the answers, and keep trying until it says the answer is right.
One of the classic examples of that last one is prime factorization. In general it's very hard to come up with the two primes that were multiplied to create a very large number, but if the quantum computer coughs up a candidate it's downright trivial to check whether that's a solution.
do {
solveProblem();
} until (getPhotonPosition() && getPhotonVelocity());
Faith is a willingness to accept something w/o complete proof and to act on it. Reason allows you to correct that faith.
Actually quantum computing is, by design, probabilistic. Every specifically quantum algorithm (even Shor's infamous factoring algorithm) gives incorrect results by design for the simple reason that it's really not possible to have quantum algorithms which succeed all the time (unless you forgeo their quantum properties). So long as the probability of a correct answer is strictly greater than 0.5, however, one only has to repeat the computation a constant number of times to get the probability of success arbitrarily close to 1.