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First Evidence That Google's Quantum Computer May Not Be Quantum After All224

KentuckyFC writes "In May last year, Google and NASA paid a reported \$15 million for a quantum computer from the controversial Canadian start up D-Wave Systems. One question mark over the device is whether it really is quantum or just a conventional computer in disguise. That's harder to answer than it sounds, not least because any direct measurement of a quantum state destroys it. So physicists have to take an indirect approach. They assume the computer is a black box in which they can input data and receive an output. Given this input and output, the question is whether this computing behavior can be best reproduced by a classical or a quantum algorithm. Last summer, an international team of scientists compared a number of classical algorithms against an algorithm that relies on a process called quantum annealing. Their conclusion was that quantum annealing best reproduces the D-Wave computer's behavior, a result that was a huge boon for the company. Now a group from UC Berkeley and IBM's Watson Research Lab says it has a found a classical algorithm that explains the results just as well, or even better, than quantum annealing. In other words, the results from the D-Wave machine could just as easily be explained if it was entirely classical. That comes on the back of mounting evidence that the D-Wave computer may not cut the quantum mustard in other ways too. Could it be that Google and NASA have forked out millions for a classical calculator?"
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First Evidence That Google's Quantum Computer May Not Be Quantum After All

• It makes me feel better (Score:5, Funny)

on Monday February 03, 2014 @12:09PM (#46141071)

I am at such a loss of understanding what exactly quantum computers are and how they work (no matter how hard I try)... so it makes me feel like less of an idiot when I find out that it's so complicated that even Google engineers aren't even sure if what they have IS one.

• Re:It makes me feel better (Score:5, Funny)

on Monday February 03, 2014 @12:34PM (#46141317)

All I can offer you is a quantum of solace.

• Re:It makes me feel better (Score:5, Funny)

on Monday February 03, 2014 @02:31PM (#46142789)

All I can offer you is a quantum of solace.

The six people in the world that understood that movie title thank you.

• A quick overview (Score:5, Interesting)

on Monday February 03, 2014 @01:35PM (#46142049) Homepage Journal

Quantum effects are not hard to understand, they're just counter-intuitive to everyday experience. This site [lesswrong.com] has a good explanation of QM, and how it differs from normal experience.

The universe doesn't work in specifics until something is measured. It doesn't choose parameters for particles (spin, position, &c) at the outset and let things evolve like little billiard balls.

Instead, it uses probabilities which flow and interact with one another. These probabilities have both amplitude and phase, so that the interactions are wave-like as well as probability-like. For example, because of this wave-like interaction it's possible for two non-zero probability flows to completely cancel to zero.

The universe appears to calculate probabilities for all possible outcomes and only choose one when the measurement is made. When particles are entangled, you increase the number of possible outcomes. For each new particle that becomes entangled you increase the number of possible outcomes by a factor of two. Ten particles will have 2^10 = 1024 possible outcomes, and so on.

So to do math at the quantum level, you take a set of entangled particles and set up the measurement so that division with no remainder has probability one while division with any other remainder has probability zero. Then load your register with all the integers, let the probabilities interact, and take the measurement.

You have just performed division using all the integers at once.

If you can do this with a reasonably large register you can check all the factors of a composite number in linear time - the time it takes you to load sqrt(P) divisors into the register.

Easy peasy!

An interesting side-note is the idea of the universe keeping track of all possible outcomes until a measurement is made. If this works as predicted, the universe will have to keep track of 2^3000 possible outcomes, depending on the key length (3000 is the recommended RSA key length to be secure until 2030).

There are only ~10^80 = 2^240 atoms in the universe. If a quantum computer works as predicted, one wonders how and where the universe keeps track of all these states. At the very least, quantum computing is interesting because it will allow us to probe the limits of the universe in an entirely new domain.

Here's hoping we don't encounter a buffer overflow.

(Note: Some facts were harmed in the making of this explanation.)

• Re: (Score:2)

What baffles me is why can't they just open up this computer and see how it works? Is it really that much of a black box? Sure there may be a classical algorithm that has the same performance, but so what? Nothing requires that the slowest quantum algorithm always be faster than any classic algorithm. What they're doing is taking a good algorithm and then testing to see if this computer also has a good algorithm, not whether it has a quantum effect or not.

A better comparison is to take the algorithm tha

• Re: (Score:2)

I'm glad someone finally asked this, because I was confused on this the first few headlines on this topic.

What baffles me is why can't they just open up this computer and see how it works?

The problem, as usual, is badly written headlines and summaries. It's not a literal black box. It's not actually in disguise. The scientists know what is inside and what it does. That isn't the problem. The problem is that we aren't sure we understand how those parts actually function. We aren't sure if the quantum effect he designers were trying to take advantage of is actually happening. The re

• Re: (Score:3)

You stated the number of atoms in the observable universe. The universe is most likely infinite. It's also possible that the natural constants change at the ultra large scales. You also imply that the universe has some kind a purpose, because it needs to keep track of all of the states. There necessarily is no purpose and no need to track the states. It can be a freely oscillating system, although the vibrations are mostly subdued because the universe is almost totally frozen by now in it's current(?) rendi

• Re: (Score:2)

The universe is most likely infinite.

Unless you consider Olber's Paradox [wikipedia.org], which is asks the question "why is it dark at night?". The simplest explanation is that the universe is finite. If it were in fact infinite, it would have to be decreasing in density faster than n^-1 (if my quick estimate of exponents is correct).

• Re: (Score:2)

Because of the expansion it's impossible for us to perceive the light outside of our cone. In other words the light cones of other possible bubbles or objects may never intersect with ours. The light simply can't reach us because the universe itself expands and makes the travel impossible. This actually is the mainstream explanation for the paradox, in the link you submitted.

• And this is why I'm skeptical of quantum computing (Score:2)

An interesting side-note is the idea of the universe keeping track of all possible outcomes until a measurement is made. If this works as predicted, the universe will have to keep track of 2^3000 possible outcomes

The theory says that a quantum computer can simply offload this monumental task to a vague entity that you call "the universe." Doesn't this strike you as a little too good to be true? The ultimate "free lunch," or a violation of conservation of-something-or-other?

TFA makes me feel justified in my skepticism.

Another question... if quantum computing is real, can it be used to speed up Bitcoin mining by a few orders of magnitude?

• Re: (Score:2)

The universe doesn't work in specifics until something is measured. It doesn't choose parameters for particles (spin, position, &c) at the outset and let things evolve like little billiard balls.

Instead, it uses probabilities which flow and interact with one another.

This makes ZERO sense, unless our universe is a running simulation and those are just optimization artifacts.

• Re: (Score:2)

some experiments suggest that is the case.
• Re: (Score:2)

Don't worry. What Quantum computers primarily do is "not working" and transferring money form the gullible to their creators. Google engineers are not as smart as they generally think they are and some are outright idiots or at best semi-competent. Just read the papers produced there. Many are pathetic and would at bets qualify as an average semester-thesis result.

• Quantum Cash! (Score:3, Insightful)

on Monday February 03, 2014 @12:18PM (#46141147) Journal

Why buy something that isn't demonstratively faster than the old stuff...

I mean if the difference is so small that there is some sort of debate about if it is effectively working or not, then it seems to me at that point cost should be the deciding factor. I doubt these D Wave machines are any cheaper than the old stuff.

• Re:Quantum Cash! (Score:5, Interesting)

<shawn-ds@willden.org> on Monday February 03, 2014 @12:26PM (#46141233) Homepage Journal

Why buy something that isn't demonstratively faster than the old stuff

Research often requires baby steps. If you ignore every new idea whose first (or hundredth!) iteration isn't already better than what we have, you'll ignore every new idea.

• Re: (Score:3)

Unfortunately, D-Wave's proprietary approach is getting in the way of proper "baby-steps" research. Before you go selling a zillion-qbit \$15M black-box system, productive research would involve letting independent research groups perform stringent tests for "quantumness" on, e.g., a simplified 2-bit system. D-Wave is selling an obfuscated system, getting in the way of low-level bare-hardware fundamentals that really advance research.

• Re: (Score:2)

D-Wave's "proprietary approach" makes me think it's nothing but fraud, simply because if it actually worked, they'd do better to explain more.

• Re: (Score:2)

So why did all these smart guys at Google and Lockheed fall for it?
Very strange, unless they know more than we do, and haven't said so because of NDA issues.

Or maybe the DWave guys are just really good pitchmen.
• Re: (Score:2)

At some point, it has to be cheaper to just open up your processes to observers. You could jeopardize your trade secrets, but at least people could believe your product was for real.

"Some point" might be now, if no more machines are going to be purchased until the high profile labs (Google / NASA, USC / Lockheed) report positive results.

• D-Wave Seems to do Some Stuff Fast (Score:2)

Yeah, I've never been clear on exactly what stuff D-Wave does fast, or how it does it, in spite of having been to a few of their presentations, and D-Wave has always been clear upfront that their machine works differently from Shor's proposed quantum computers that sparked all the "It'll let you break crypto" interest.

But they apparently at least run some kinds of demos faster than you'd expect them to be able to do with conventional computers, and do it in ways that are interesting enough for a few big p

• Re: (Score:2)

Definitely! But some customers believed they were getting a genuine speedup from the quantum effects and it being a true quantum computer. I think it's relevant to *them* whether they could accomplish the same thing with (classical) commodity hardware and a grad student to implement the (classical) algorithm, which seems to be the case.

• Re:Quantum Cash! (Score:5, Informative)

on Monday February 03, 2014 @12:33PM (#46141309)

Before this research, it was demonstrably faster at some things, and slower at things a quantum computer is not good at. So they did exactly what you expect.

• Re:Quantum Cash! (Score:5, Informative)

on Monday February 03, 2014 @01:45PM (#46142155) Homepage

Why buy something that isn't demonstratively faster than the old stuff...

I mean if the difference is so small that there is some sort of debate about if it is effectively working or not, then it seems to me at that point cost should be the deciding factor. I doubt these D Wave machines are any cheaper than the old stuff.

Part of the problem has been D-Wave's confusing abuse of terminology:

1) They claim their device is a computer, but it's not according to the usual definition (a Turing machine with bounded tape (RAM)). It's more similar to an ASIC (application-specific integrated circuit).
2) They claim their device is a quantum computer, but it's not according to the usual definition (a device which requires quantum phenomena to operate). There is some evidence it uses quantum effects, but they don't appear fundamental to its operation (otherwise we wouldn't be having this quantum-or-not merry-go-round).
3) They claim their device solves its (application-specific) problem 35,000x faster than a classical machine, but in fact they had programmed the classical machine with a much harder problem (finding an exact solution, rather than an approximate one). When a classical computer was programmed to solve the same problem as D-Wave's machine, the classical machine was faster.
4) They consistently conflate quantum algorithms (algorithms inspired by quantum mechanics) with quantum computing (which requires quantum mechanics to operate). Their machine implements a 'quantum simulated annealing' algorithm, but this doesn't require a quantum computer to run. Likewise, a regular 'simulated annealing' algorithm doesn't require a heat engine to run. Likewise a 'genetic algorithm' doesn't require a DNA-based computer to run.
5) They keep moving the goalposts to remain as impressive-but-vague as possible. Rather than showing definitive results to back up their claims, they keep making claims then weakening them afterwards when researchers show them to be false. This is like an inverse No-True-Scotsman; academics have a clear definition of what a quantum computer is, and D-Wave keep trying to expand that definition it to include their machines.

In short, Google and NASA bought their machines when there were claims bouncing around about 35,000x speedups, but these were subsequently found to be flawed.

I'm all for investing in basic research, but it often looks like D-Wave's research output is coming from their marketing department rather than their scientists and engineers :(

• Re: (Score:2)

Best explanation I've seen.

Remind you of Cold Fusion?
• Re: (Score:2)

Likewise, a regular 'simulated annealing' algorithm doesn't require a heat engine to run.

I know what you're trying to say, but think about what you just said for a minute...

• Re: (Score:2)

Why buy something that isn't demonstratively faster than the old stuff...

The horse-less carriage wasn't originally faster than the horse-full type, but people bought them anyway. Perhaps they were better in other ways, people saw their potential or they were just novel. Anyway, adoption brought improvements, not just in the vehicles but roadways too, and ultimately, the automobile changed the way we all live - for, arguably, better and worse...

• Re: (Score:3, Insightful)

by Anonymous Coward

Suppose someone tried to sell you a "horseless carriage" that was pulled by a big black box. You insert hay and oats into one side of the black box, then it goes "clop-clop-clop" and pulls the carriage at about the speed of an old horse in a big black box. If you watched closely enough, you'd observe horse turds falling out of the back of the box. That, so far, is what D-Wave's "quantum computer" looks like to astute outside observers. How much are you going to pay to be on this "leading edge" of carriage t

• Re: (Score:2)

Why buy something that isn't demonstratively faster than the old stuff...

I mean if the difference is so small that there is some sort of debate about if it is effectively working or not, then it seems to me at that point cost should be the deciding factor. I doubt these D Wave machines are any cheaper than the old stuff.

Because they couldn't afford not to, just like Spain couldn't afford not to finance Columbus. The risk is cushion change compared to potential reward.

• Who cares? (Score:3, Insightful)

on Monday February 03, 2014 @12:18PM (#46141153) Homepage Journal
Obviously, you don't have a use for a quantum computer if you can't find a way to determine if it's a quantum computer. If it's just speed, what you want is a super-computer. If it's the ability to perform certain calculations, they simply don't work on a classical computer (or take eternity, even for a super-computer).
• Re:Who cares? (Score:4, Funny)

on Monday February 03, 2014 @12:28PM (#46141257) Homepage

Obviously, you don't have a use for a quantum computer if you can't find a way to determine if it's a quantum computer.

Unless the act of trying to find out changes the answer, of course.

• Re: (Score:3, Interesting)

> Obviously, you don't have a use for a quantum computer if you can't find a way to determine if it's a
> quantum computer

This. How are they even programming this thing? As I understand it, a quantum computer doesn't just take your classical function and execute it faster; but instead would come at the problem via an algorithm designed to find the answer using algorithms that rely on quantum effects.

Is there any reason to believe a quantum computer algorithm, run through a classical system, should prod

• Re: (Score:2)

If I understand it correctly, this thing is designed to simulate annealing. Annealing is he process the happens when you slowly cool a metal alloy: atoms are bouncing around with lots of thermal energy at first, then less and less. As you cool them, they're more likely to get stuck in low energy configurations rather than high. You can do most non-convex (and convex I suppose, but there are better ways to solve those) optimization problems using simulated annealing.

Simulated annealing (or quasi-simulated

• Re: (Score:3)

How are they even programming this thing?

Simple, they use the Python library [dwavesys.com].

No joke, you use use statements like:

blackbox_answer = blackbox_solver.solve(obj, num_vars, cluster_num = 10, \
min_iter_inner = blackbox_parameter, max_iter_outer= blackbox_parameter, \
unchanged_threshold=blackbox_parameter, max_unchanged_objective_outer=blackbox_parameter, \
max_unchanged_objective_inner = blackbox_parameter, \
unchanged_best_threshold = blackbox_parameter, verbose=0)

As Megol said though it only works for certain problems. Their Python class is really called "BlackBoxSolver."

• Re: (Score:3)

Your point doesn't make sense. If they are TESTING quantum states, they are obviously creating what they think are quantum logic gates -- and NO this isn't going to work faster than their desktop computer. It's not like they've got an entire CPU or the ability to recognize the states faster.

I'm guessing that a Quantum computer would be great for finding data sets like "is the answer within this range" -- as all the results could be superimposed, but no state found. So if you were suing one to crack a passwo

• Re: (Score:2)

Obviously, you don't have a use for a quantum computer if you can't find a way to determine if it's a quantum computer. If it's just speed, what you want is a super-computer. If it's the ability to perform certain calculations, they simply don't work on a classical computer (or take eternity, even for a super-computer).

Not quite, since one of the best 'definitely quantum' results we have so far is that 15 = 3 * 5, which is trivially found on a classical machine.

I would say instead, that if getting a correct result doesn't determine whether it's quantum or not, then it's not quantum in any 'meaningful' way (in the sense that the transistors in my laptop's CPU aren't quantum in a 'meaningful' way).

• Re: (Score:2)

That is the point though. Why do you need a quantum computer? What business case does this solve? What engineering problem? If the answer is "it's like 10% faster than using a regular computer," you don't need a quantum computer. If the answer is "we can't physically solve this problem on a regular computer--you must brute force through every possible answer and validate, which takes longer than the universe will continue to exist,", then you need a quantum computer. If the answer is "we can do this,

• Re: (Score:2)

If you don't know if you have a quantum computer, then obviously a quantum computer isn't that important. I mean if your problem isn't solved remarkably easier with a given tool, YOU DON'T NEED THAT TOOL! If it IS solved remarkably easier with that tool, then YOU DEFINITELY KNOW IF WHAT YOU'RE HOLDING IS THE CORRECT TOOL!

There are different kinds of "easy" though. Factoring integers is 'easier' on a quantum computer since we can use Shor's algorithm, but it's 'harder' because we need large, expensive, supercooled apparatus, and it's 'harder' because we can't entangle more than a handful of qubits. If I calculate that the integer I want to factor will take, let's say, 100 years on classical computers, it might be worth my time to invest 20 years developing a quantum computer to perform the same work in a much shorter time.

Al

• Re: (Score:2)

The transistors in your CPU are most definitely quantum in a meaningful way. If it wasn't, the electrons would arrive at the gate and just refuse to keep moving. Great for low power and leakage reduction, but sucky for playing Bioshock.

• Re: (Score:2)

I want to factor the number 15. Gimme something running Shor...
• Would D-Wave Take That Risk? (Score:5, Interesting)

by Anonymous Coward on Monday February 03, 2014 @12:19PM (#46141167)

Do we really think that D-Wave Systems would take that risk? They have to know that just about every major university and tech company will try to prove them wrong. Not to mention that Google will probably spend more to verify this purchase than they made on the purchase itself.

I don't know D-Wave Systems from Adam, but is this a risk they would take?

• Re: (Score:3)

A better question is if they don't mind the risk if they already got their money.
• Re: (Score:2)

(1) For fifteen million dollars, I could find a lot of people willing to take that risk. (2) Even people who would not decide to take the risk normally would take the risk under certain circumstances. Including things as simple as "I need to tell the investors something to cover up the fact that I couldn't do X."

I'm not saying they HAVE taken the risk--or even that they would. I'm just saying that that's not a reliable question to guide you on whether someone did something except in exceptionally rare ci

• Re:Would D-Wave Take That Risk? (Score:5, Insightful)

on Monday February 03, 2014 @12:29PM (#46141259)

Even better, at least one group of smart people was fooled, and it took a group from UC Berkeley and IBM's Watson Research Lab to show a plausible classical algo. If it is fraud, it is well executed. That makes me believe they actually do have a crappy quantum computer, or believe they do.

And, with an actual product, people are hammering on it in ways that will prompt quant research into being able to prove or disprove how it works. Fraud or not, its a boon to everyone who didn't pay for it directly.

• Re:Would D-Wave Take That Risk? (Score:5, Interesting)

on Monday February 03, 2014 @12:37PM (#46141353)

Chances are, they don't know themselves exactly how "quantum" the system is. It's unlikely to be an outright fraud --- there's something other than a Core 2 Duo on the inside faking quantum results --- but a system working on the hairy edge of current technical understanding. They've built something that has a bunch of cryogenic doodads and performs annealing, but the technical understanding isn't all there. That said, they have demonstrated signs of acting in bad faith --- being very cagey about offering real details, and performing poorly-done comparisons against sub-optimal classical systems. So, they know that even they don't know whether the system they have lives up to claims, and are acting like a for-profit corporation rather than researchers with integrity about it.

• Let's not generalize about corporations. (Score:2)

When for-profit corporations perform research, they usually do so with integrity, i.e., their goal is to genuinely advance the state-of-the-art of whatever field is being researched. Only in a small minority of cases is their goal to perpetrate a scam. Just sayin.

• Re: (Score:2)

You are so wrong. The way that corporations use the patent system is a "scam". They extort money from each other as well as suppress innovation. Just look at the patent war between Apple and Samsung. It has nothing to do with capitalism. There is no public benefit in this vast world wide litigation. They fight to become the dominant monopoly so they can maximize profit without government oversight or competition

• Re: (Score:2)

What risk?

And would enron execs really take the risk of running dirty books?

besides, the one person who "knows" how D-Waves machine works might not be making any money if he didn't know "how it works" - same goes for a lot of the scientists they employ who can wash their hands anyways.

the point is still this: why pay 15 million for a quantum sticker on a machine that may or may not be a quantum computer? you know it seems to me only a quantum scientist would come up with a scam like that.... and then clai

• Don't forget there's another out there. (Score:2)

Lockheed Martin also has a D-Wave system, so let's not forget that's already churning away for some three letter agency somewhere.
• Re:Don't forget there's another out there. (Score:4)

on Monday February 03, 2014 @12:48PM (#46141449)
WARN: THERE IS ANOTHER SYSTEM...

stupid caps filter, it's supposed to be all in caps
• Re: (Score:2)

For anyone who (like me) didn't understand the reference: Colossus [wikipedia.org]

Thank you for that, it was an interesting read and quite pertinent to the subject matter. Someone throw some mod points at that person!

Google may or may not want to acquire D-Wave Systems....

• Well ... (Score:5, Funny)

on Monday February 03, 2014 @12:26PM (#46141229) Homepage

Maybe it simultaneously both is and isn't a Quantum computer? :-P

• Re: (Score:2)

Maybe it simultaneously both is and isn't a Quantum computer? :-P

Here kitty kitty!

Woof!

• You fools! (Score:3, Funny)

on Monday February 03, 2014 @12:34PM (#46141323)
You changed the outcome by measuring it!
• Unlimited power (Score:5, Funny)

on Monday February 03, 2014 @12:40PM (#46141369) Journal

I have a device for sale which generates free, unlimited power. The catch is that you cannot measure the power output or it won't function. If you put any load on the device you are directly or indirectly measuring the power, and thus it won't work. So just know up front that stipulation and use the device accordingly.

• Re: (Score:3)

I have a device for sale which generates free, unlimited power. The catch is that you cannot measure the power output or it won't function. If you put any load on the device you are directly or indirectly measuring the power, and thus it won't work. So just know up front that stipulation and use the device accordingly.

False equivalence police are coming for you. Quantum computers do produce output that theoretically can be tested and validated. Your imaginary power device, by your own definition does not accept load so does not produce output. Not a similar device. It would have been better to compare it to the computer in Hitchhiker's Guide to the Galaxy that came up with '42' as the answer to the ultimate question. Since you can't (as in, no present ability to) validate the answer how do you know the computer actually

• Re: (Score:2)

"Police" has no business trying to control ideas. Not that they and people like you try to do so anyways.

• Re: (Score:3)

You wouldn't be related to a guy called Rossi?

• Re: (Score:3)

Unlimited power

I have a device for sale which generates free, unlimited power. The catch is that you cannot measure the power output or it won't function. If you put any load on the device you are directly or indirectly measuring the power, and thus it won't work. So just know up front that stipulation and use the device accordingly.

This is a perfect description of God.

• You know what you have to do, Google... (Score:2)

No conventional computer can replicate a quantum computer's processes. The only way to check your quantum computer's results... is to buy another one.
• Re: (Score:2)

Nonsense. There are numerous problems that are far easier to check than to compute. Factorization, for example. Just multiply to check.

Seems that actual CS knowledge is getting scarce on /.

• Re: (Score:2)

Ah, if only it were the 90s again.

Whoosh.
• Does it matter? (Score:2)

I realize the desire to tout the fact that you use a quantum computer and that if D-wave is selling a "quantum computer," they should deliver something that performs quantum computations. However, if it does what it's supposed better than other classical computers, then the money is not a waste. Unless the spending was just for show, then too bad.
• simple solution? (Score:2)

what if you just look at the chip contents under a microscope? i figure if you put that much money into the company that you should be able to inspect the resulting chip. seems like it would be a simple to determine if it's just a plain ol' IC or not.

• Re: (Score:3)

Erm. The architecture of the D-wave core chip is sufficiently well known. [wordpress.com]. What is not know is if quantum effects are playing a role in the functioning. It is designed to encourage and at least allow quantum effects based on the Ising model [wikipedia.org]. The question is of course, does the quantum magic actually occur?, and if it does, does it help?.

Or was that IC thing supposed to be funny?

• Re: (Score:2)

Too bad that D-Wave blog post you linked to is full of outright fabrications/distortions. The machine they have is an annealer, not a "fast NP-complete problem solver." It does not solve NP-complete problems. An NP-complete problem is, e.g., finding the best solution to a "traveling salesman" problem --- this computer doesn't do that. Finding a probably-good-but-not-the-single-best solution to a "travelling salesman" problem is not an NP-complete problem; there are polynomial-time classical algorithms that

• Re: (Score:2)

The same thing occurred to me. The thing is, DWave's chip definitely doesn't have a bunch of transistors on it executing a conventional program. It's more like a little physical simulation on a chip. The question is whether that particular setup behaves classically or not.

• The ignoramuswho wrote the headline of the summary (Score:2)

should consider him/herself informed that models fitting data are do not constitute evidence of anything.

Especially when two supposedly incompatible (debatable) models fit the data, it just means that you don't have a clue about what is really going on. A polynomial equation of sufficient order will fit an elephant. It does not mean you have explained what an elephant is. It is not evidence of the non-parabolic-ness of an elephant.

• Re: (Score:2)

The title is completely valid with regard to the strength of the computing model. The issue is that this "computing device" is basically useless for one more thing that was its core claim to being useful.

• Re: (Score:2)

should consider him/herself informed that models fitting data are do not constitute evidence of anything.

Except for all of scientific knowledge, of course.

It's pretty clear that you, just like most of the other posters, don't understand what D-Wave's machine does or how it's being tested.

• the only obvious solution (Score:2)

There's no point in testing it now or trying to form an opinion at the risk of being wrong. D-Wave claims that really soon they'll have a quibit count (or whatever) high enough to break rather difficult encryption instantly as opposed to hours/months/centuries. If it spits out an answer, THEN it will be incontrovertible proof. Until then, it's not wise to say they're faking it or not faking it. I somehow doubt that they hired a mathematician to invent whatever algorithm it took the rest of the world a w
• Re: (Score:2)

They cannot do that. Factoring requires far too many entangled qbits. They are not going to get there with their technology, ever. And for symmetric encryption, they just halve the bits. That is not going to help with 256 bit ciphers, they are still completely secure even with a (very, very unlikely) working quantum computer.

No, like any good scammer, they see they can profit from this a bit longer.

• Occam's razor (Score:2)

Now a group from UC Berkeley and IBM's Watson Research Lab says it has a found a classical algorithm that explains the results just as well, or even better, than quantum annealing.

So we have two possibilities here:

1) D-Wave has built a device that at least theoretically can exist, which works more-or-less as advertised, or
2) D-Wave came up with a previously unknown solution to a class of computationally difficult problems, and would rather fleece a handful of investors than simply profit legitimately
• Re: (Score:2)

You miss the point. This discovery proves that this expensive box is useless, no matter what mechanism it uses...

• Re: (Score:2)

The simple answer to your question, which is admitted by D-Wave when pressed (though not made obvious in their PR literature) is no, D-Wave cannot run Shor's algorithm. The D-Wave is definitely not a full quantum computer in the most general sense; at best, it can carry out a very limited subset of what a general-purpose quantum computer can do ("quantum annealing" problems). At worst (and nothing better has been conclusively demonstrated), it can't do anything you can't do with cheaper fully-classical hard

• No surprise at all (Score:2)

That this thing is not a quantum computer in any meaningful way was clear from the beginning. But some people want to believe, no matter what. Sometimes that gets expensive...

• Nonsense (Score:4, Informative)

on Monday February 03, 2014 @03:42PM (#46143509)

D-Wave has Josephson junction qubits on their chip and couple them. Yet, somehow they are supposed to end up with a machine that is a classical annealer? Although the behavior of the box is exactly what you'd expect from a quantum annealer?

Seems rather far fetched.

I wished before anybody was writing about D-Wave they'd watch this video form the last Q+ hang-out where the Troyer et. al. research into the characteristics of the D-Wave machine was presented. [wavewatching.net]

• And to think..... (Score:2)

A TI-99 could sale for so much money...

• Citation needed (Score:2)

The fine article claims:

Most physicists fully expect a useful quantum computer to eventually emerge, [...]

I am a physicist and I don't think a useful quantum computer will ever emerge. The problem is very simple. In order for a quantum system to calculate exponentially faster than a classical system, it must contain exponentially more useful information which makes it exponentially more sensitive to noise. An early computer researcher (perhaps Jon von Neumann) used a similar argument to conclude that digital computers would eventually supersede analog computers because the precisio

• misreporting (Score:2)

the article is mis-reported... or at the very least confusing. if you read the article carefully it describes failures of some of the researchers, followed by reporting the successful analysis and conclusions, possibly by a completely different team. the time-lines are not made clear, either. this sounds like a reporter decided to mis-represent the facts.

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