MIT And HP Announce Joint Quantum Computer Project 174
MetaCow writes: "CNN is running this article which describes a joint effort between MIT and HP to build a quantum computer. Nothing expected any time soon, though: 'Quantum computing research is farsighted, and it may take 10 years to develop a fully operational quantum computer ...'"
The Quantum Computing Swindle (Score:2, Interesting)
This isn't flamebait - it's definitely a subject worthy of discussion. I, for one, have great reservations about whether this is a viable technology. This is especially important since so much money and attention is being poured into research, perhaps often without a real understanding of the basic principles. I happen to know people in Gershenfeld's lab, and know full well their tendencies to let the hype get out of hand.
Perhpas HP is spending the money as a marketing/PR effort, rather than them intending to get real work done. That would explain the press release.
So here it is; I hope nightlight3 will chime in.
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"If one existed, a quantum computer would be extremely powerful; building one, however, is extremely challenging,"
Extremely challenging, like in "it can't work and it won't ever work, but I hope the government and the industry sponsors won't find that out, at least until I retire, preferably after I am dead."
The whole field of Quantum Computing is a mathematical abstraction (fine, as any pure math is, as long as you don't try to claim that's how the real world works). Its vital connection with the real world is based on a highly dubious (even outright absurd, according to some physicists, including Einstein) conjecture about entangled quantum states (roughly, a special kind of "mystical" non-local correlation among events) which was actually never confirmed experimentally. And without that quantum entanglement the whole field is an excercise in pure abstract math with no bearing on reality.
While there were number of claims of an "almost" confirmation of this kind of quantum correlations (the so-called Bell inequality tests), there is always a disclaimer (explicit or, in recent years, between the lines as the swindle got harder to sell), such as "provided the combined setup and detection efficiency in this situation can be made above 82%" (even though it is typically well below 1% overall in the actual experiment; the most famous of its kind, Aspect experiment from early 1980s had only 0.2% combined efficiency, while 82% is needed for actual, "loophole free" proof) or provided we assume that the undetected events follow such and such statistics, etc. The alternative explanations of those experiments (requiring no belief in mystical instant action-at-a-distance), which naturally violate those wishfull assumptions, are ignored, or ridiculed as unimportant loopholes when forced to debate the opposition, by the "mystical" faction. After all, without believing their conjecture all the magic of quantum computing, quantum cryptography, quantum teleportation, along with funding, would vanish.
For those interested in the other side of these kinds of claims, why it doesn't work and why it will never work, check the site by a reputable British physicist Trevor Marshall, who has been fighting, along with a small group of allies, the "quantum magic" school for years:
Quantum Mechanics is not a Science [demon.co.uk]
Unfortunately, the vast bulk of the research funding in this area goes to the mystical faction. As long as there are fools with money, there will always be swindlers who will part the two.
For a more popular account, accessible to non-physicists, of the opposing view, you can check a site by a practical statistician (and general sceptic) Caroline Thompson:
Caroline Thompson's Physics [aber.ac.uk]
DMCA vs Quantum computers (Score:3, Interesting)
Interesting Implications (Score:2, Interesting)
1. No more encryption. Quantum computers can crack block ciphers with ease, as well as assymetric public key cyphers. Bigger keys? Just use more qubits. Hmm... can anonymous networks (MixMaster, Freenet, Publius, etc...) exist without encryption? Can banking exist without encryption? How about online transactions in general?
2. Uber compression. Everything digital occurs in the Pi sequence somewhere right? Well, quantum computers might be able find that offset and length within Pi, LCG's, or any other kind of sequence.
Imagine downloading a 4 hour DIVX using 20 bytes. 4b sequence ID, 8b offset, 8b length. That is the same length as an IP header...
3. Massive optimization. Remember all those NP-complete problems you learned in comp. sci. ? No more simmulated annealing, genetic algorithm, guesstimation methods. Qubits can find the optimal solution instantly. No more intense calculations for hours/days to find meager 'near' optimal solutions. P.S. NP-complete type problems shows up in almost every complex system in every field / domain.
So what are the implications of this kind of computing becoming available in ten years? It's a wonder we dont hear more about this when reading about quantum computers. The effect they will have when available is almost more interesting than the implementation
Some of the challenges (Score:3, Interesting)
"Dr Cory says that the program for factorising large numbers [400 digits] will require about 1,000 qubits simply to store the problem. But each of these qubits will require dozens of extra qubits for error-checking. That means that a useful computer will need tens of thousands of qubits to come up with a reliable answer. At seven and counting, that goal is a long way off. "