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Some Scientists Question Whether Quantum Computer Really Is Quantum

Unknown Lamer posted about a year ago | from the qbits-all-the-way-down dept.

Supercomputing 170

gbrumfiel writes "Last week, Google and NASA announced a partnership to buy a new quantum computer from Canadian firm D-Wave Systems. But NPR news reports that many scientists are still questioning whether new machine really is quantum. Long-time critic and computer scientist Scott Aaronson has a long post detailing the current state of affairs. At issue is whether the 512 quantum bits at the processor's core are 'entangled' together. Measuring that entanglement directly destroys it, so D-Wave has had a hard time convincing skeptics. As with all things quantum mechanical, the devil is in the details. Still it may not matter: D-Wave's machine appears to be far faster at solving certain kinds of problems (PDF), regardless of how it works."

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170 comments

If it works - it works (2, Insightful)

telchine (719345) | about a year ago | (#43793215)

Does it really matter so long as it does what it says on the tin? It works faster, surely that's all that matters?

Re:If it works - it works (5, Informative)

Anonymous Coward | about a year ago | (#43793295)

You really need to RTFA. It's slower than an optimized implementation of the same thing on a classical computer (and one that costs a lot less than $10m).

Re:If it works - it works (5, Informative)

Certhas (2310124) | about a year ago | (#43793661)

Indeed, the summary is misleading.

Citing from Aaronsons blog:

Among the many interesting comments below, see especially this one by Alex Selby, who says he’s written his own specialist solver for one class of the McGeoch and Wang benchmarks that significantly outperforms the software (and D-Wave machine) tested by McGeoch and Wang on those benchmarks—and who provides the Python code so you can try it yourself.

and

As I said above, at the time McGeoch and Wang’s paper was released to the media (though maybe not at the time it was written?), the “highly tuned implementation” of simulated annealing that they ask for had already been written and tested, and the result was that it outperformed the D-Wave machine on all instance sizes tested. In other words, their comparison to CPLEX had already been superseded by a much more informative comparison—one that gave the “opposite” result—before it ever became public. For obvious reasons, most press reports have simply ignored this fact.

In other words, if it works, it works, except that it doesn't.

Re:If it works - it works (0)

Anonymous Coward | about a year ago | (#43794253)

Have they tried 3D printing it? Surely that is the answer.

Re:If it works - it works (1)

unrtst (777550) | about a year ago | (#43794603)

...been superseded by a much more informative comparison—one that gave the “opposite” result—before it ever became public.

Sounds eerily familiar to every discussion of quantum mechanics I've heard! ("opposite" result; gave it before even knew it existed; etc).

Re:If it works - it works (1)

Simon321 (1933722) | about a year ago | (#43795259)

Geordie Rose's (D-Wave CTO) response:

The majority of that post is simply factually incorrect.
As one example, Troyer hasn’t even had access yet to the system Cathy benchmarked (the Vesuvius – based system). (!) Yes Rainier could be beat by dedicated solvers — it was really slow! Vesuvius can’t (at least for certain types of problems). Another is he thinks we only benchmarked against cplex (not true) and he thinks cplex is just an exact solver (not true). These types of gross misunderstanding permeate the whole thing.
I used to find this stuff vaguely amusing in an irritating kind of way. Now I just find it boring and I wonder why anyone listens to a guy who’s been wrong exactly 100% of the time about everything. Update your priors, people!!
If you want to know what’s really going on, listen to the real experts. Like Hartmut.

Re:If it works - it works (2)

alexander_686 (957440) | about a year ago | (#43794937)

Here is a link to a good article.
      There were 3 tests with D-Wave going against a generic algorithm.
      It tied on 2 or the 3 tests, but beat the generic algorithm running 3,600 times faster.
      However, if it went against a specialized algorithm it was just as fast.

http://www.economist.com/news/science-and-technology/21578027-first-real-world-contests-between-quantum-computers-and-standard-ones-faster [economist.com]

Re:If it works - it works (4, Funny)

RDW (41497) | about a year ago | (#43793297)

You may say that now, but wait until PETA find out about the number of cats and flasks of cyanide their prototype gets through every month...

Re:If it works - it works (1)

Anonymous Coward | about a year ago | (#43793553)

You may say that now, but wait until PETA find out about the number of cats and flasks of cyanide their prototype gets through every month...

Yeah, they'll be taking notes. [petakillsanimals.com]

Read the blog post (4, Interesting)

oGMo (379) | about a year ago | (#43793327)

The problem is that it's not faster, and while there's a study that concludes it is, the blog post specifically invalidates this:

Namely, the same USC paper that reported the quantum annealing behavior of the D-Wave One, also showed no speed advantage whatsoever for quantum annealing over classical simulated annealing. In more detail, Matthias Troyer’s group spent a few months carefully studying the D-Wave problem—after which, they were able to write optimized simulated annealing code that solves the D-Wave problem on a normal, off-the-shelf classical computer, about 15 times faster than the D-Wave machine itself solves the D-Wave problem! Of course, if you wanted even more classical speedup than that, then you could simply add more processors to your classical computer, for only a tiny fraction of the ~$10 million that a D-Wave One would set you back.

About the paper claiming it's faster:

As I said above, at the time McGeoch and Wang’s paper was released to the media (though maybe not at the time it was written?), the “highly tuned implementation” of simulated annealing that they ask for had already been written and tested, and the result was that it outperformed the D-Wave machine on all instance sizes tested. In other words, their comparison to CPLEX had already been superseded by a much more informative comparison—one that gave the “opposite” result—before it ever became public. For obvious reasons, most press reports have simply ignored this fact.

Re:Read the blog post (1)

LordLimecat (1103839) | about a year ago | (#43793821)

Sounds like it really does not matter then; who cares whether its quantum or not when it provides less value at a higher price?

Re: Read the blog post (2)

sometext (2537330) | about a year ago | (#43794011)

Surely there is still value in advancing the technology, $10m seems a small price to pay considering.

Re: Read the blog post (4, Insightful)

Anonymous Coward | about a year ago | (#43794093)

But what if I build a standard internal combustion engine, wrap it in a sheet of tin foil, and proclaim that I have created a portable cold fusion generator? Is that worth $10m for advancing cold fusion technology, despite the fact that it's not actually cold fusion?

The issue with D-Wave isn't that it's not as good as classical methods, it's that it probably isn't what it claims to be.

Re: Read the blog post (1)

alexander_686 (957440) | about a year ago | (#43795045)

D-Wave is selling this as a commercial product, and as a commercial product it seems lacking. Now, if we are talking about increasing fund on R&D – that would be a different story.

Re: Read the blog post (1)

lgw (121541) | about a year ago | (#43795069)

Surely there is still value in advancing the technology, $10m seems a small price to pay considering.

I believe that's exactly the scam here. D-Wave is selling something, something which solves problems, but is much less interesting than claimed.

Paying millions for really impressive PowerPoint slides only leads to scams. Actual proof of technological advancement if worth paying for, but unproven claims of such are worthless.

Re:Read the blog post (4, Interesting)

MozeeToby (1163751) | about a year ago | (#43794023)

Because if it is quantum it's a generation 0 (barely out of prototype) implementation going up against a generation... oh I don't know... 30+ classical computer. If it's not quantum, if it's basically an ASIC chip designed to solve simulated annealing problems (intentionally or not), it's worthless even as research. What they are selling is a research and training system, so that engineers can learn what kinds of problems can be solved on the hardware that will, presumably, get much more powerful going forward.

Look at it this way, the current D-wave machine has 512 qbits and a modern PC can match it's speed. Double the qbits and you end up with a simulation space several million times larger, the 15x faster is going to seem laughable when the problem you are solving is trillions of times larger and the D-Wave solves in constant time while your PC runs an algorithm that's O(n^2). If, if, what D-wave is selling is using quantum affects.

Re:Read the blog post (1)

lightknight (213164) | about a year ago | (#43794695)

Well, that's why we have tech, obviously, so that we can make the machine that costs $10M and makes the 'BOING" noise. /s

Re:Read the blog post (1)

Anonymous Coward | about a year ago | (#43795431)

metacomment: this is about quantum machines and programming models; I am on the fence about the D-Wave itself.

from oGMo's quote from the article:

In more detail, Matthias Troyer’s group spent a few months carefully studying the D-Wave problem—after which, they were able to write optimized simulated annealing code that solves the D-Wave problem on a normal, off-the-shelf classical computer, about 15 times faster...

This is early days -- it still takes a long time to set up these programs either way. Some experiments (CM-1 [wikipedia.org] I'm thinking of you) don't end up anywhere, but the experience from them leads to other, useful results. We just have to see what useful programming models develop and if it becomes faster to express the problem that way then to decompose it in a traditional way (taking into account both setup time and runtime).

The other point not to forget is that these are not really "computers" in the usual sense, rather they are offboard processing units. These were unremarkable in the 60s and 70s (think of offboard FP or database engines that plugged into the bus -- today's offboard GPUs are an example of this too). The whole idea is still a work in progress.

Re:If it works - it works (1)

Anonymous Coward | about a year ago | (#43793343)

But what if it isn't quantum and we've built an entire computer and don't know how it really works? At that point you may as well throw up your hands and yell magic.

Re:If it works - it works (1)

cellocgw (617879) | about a year ago | (#43794945)

But what if it isn't quantum and we've built an entire computer and don't know how it really works? At that point you may as well throw up your hands and yell magic.

I'm not so sure that anyone can really explain how a computer works, from the transistor level up thru the functioning of various hardware blocks and then thru maybe 30 layers of software abstraction. What we do have is piles of people who are very good at improving one level or another, and the results to date suggest these improvements tend to be independent, i.e. an improvement at one level rarely if ever forces a degradation at another level.

But, heck, if someone creates a *reproducible* new concept which works even better, who cares if it's not understood?

Re:If it works - it works (0)

Anonymous Coward | about a year ago | (#43795149)

Woz can! And so can anyone else who has actually built one.

Re:If it works - it works (1)

Anonymous Coward | about a year ago | (#43793421)

Measuring that entanglement directly destroys it, so D-Wave has had a hard time convincing skeptics.

Funny, here I was under the assumption that if something couldn't be measured, you had a harder time convincing skeptics (in this case, scientists and engineers) that it worked as advertised in the first place and wasn't being pawned off as magic bullshit, but I guess if you crudely staple "quantum" onto the name somewhere, it's suddenly legit and the only question that remains is just HOW magical and happy is this wondrous pay-no-attention-to-the-details black box.

Re:If it works - it works (0)

Anonymous Coward | about a year ago | (#43793589)

Even if it was faster than a classical computer (which was called into question already), for that price, you would need to know if it is faster than other options, like custom electronics or an ASIC designed for this specific problem. It shouldn't be surprising something can beat a general purpose computer at a narrow range of problems, but that doesn't necessarily mean its speed is worth the cost. At least if it actually had quantum behavior of some kind, that means there could be very specific (and possibly contrived) problems a classical electronic device couldn't compete with, although not a guarantee.

Re:If it works - it works (1)

Qzukk (229616) | about a year ago | (#43793813)

Does it really matter so long as it does what it says on the tin?

But if you put in the wrong figures, do you get the correct answer?

Re:If it works - it works (1)

Anonymous Coward | about a year ago | (#43793815)

It matters because it's theorised that quantum computers behave differently to classical computers*, not just faster. If we know whether it's quantum we can test these theories and we can make use of the differences to develop better algorithms than is possible if it isn't truly quantum.

*In complexity terms it's not known whether QP = P.

Re:If it works - it works (1)

9jack9 (607686) | about a year ago | (#43795085)

Does it really matter so long as it does what it says on the tin? It works faster, surely that's all that matters?

Nope. Need to know how it works. Need to be able to examine every aspect of it. Need to be able to model it and predict its behavior in different situations.

Heisenberg Uncertainty principle is intact... (4, Funny)

Stolpskott (2422670) | about a year ago | (#43793229)

So they know where the D-Wave system is, but they cannot definitively measure whether it is actually a quantum computer or not...

Forget whether it is Quantum or not... (1, Funny)

Dareth (47614) | about a year ago | (#43793521)

This crazy scientist kidnapped my cat and put it in a box! See if the D-Wave computer can tell me if my cat is alive or not.

Re:Forget whether it is Quantum or not... (0)

Anonymous Coward | about a year ago | (#43793693)

Don't worry, your cat is both alive, and not.

Re:Heisenberg Uncertainty principle is intact... (1)

hAckz0r (989977) | about a year ago | (#43793539)

Yes. They first started with particles, then moved on to small covalently bonded molecules. Soon after they perfected a superposition of Buckyballs they eventually went for the entire machine. Its amazing to watch the confusion among scientists as the entire structure of the machine goes into a state of superposition with being real and not real all at the same time.

Re:Heisenberg Uncertainty principle is intact... (4, Funny)

plover (150551) | about a year ago | (#43794335)

Its amazing to watch the confusion among scientists as the entire structure of the machine goes into a state of superposition with being real and not real all at the same time.

All quantum computers are real, unless declared integer.

Re:Heisenberg Uncertainty principle is intact... (0)

Anonymous Coward | about a year ago | (#43794751)

A cat is in a box - YOU cannot see it...
is it dead? is it alive? is it both?

you flip a coin but YOU dont look at it yet, what are the chances it is heads? tails?

then YOU look, the cat is dead. did you looking at the cat kill it? if so, can you posit a logical explanation?

if you said 50/50 for heads and tails, think about this.. what are the chances it is tails, AFTER YOU look at it and discover it is in fact heads..?
Obviously the chances would be Zero but the only thing to change was your level of ignorance to the facts - you looked, and you saw, and now you know the facts
You could say that you were uncertain. However the results were not based on 2 possibilities being true (or false) at the same time. Your uncertainty was based on lack of knowledge. AND THAT'S OK!!

ignorance !=superposition
just because YOU dont know the facts doesnt mean there is a superposition.
Sounds more like ignorance=superstition

Is any quantum computer really quantum? (4, Funny)

dingen (958134) | about a year ago | (#43793239)

A real quantum computer both is and isn't at the same time.

Re:Is any quantum computer really quantum? (5, Funny)

Anonymous Coward | about a year ago | (#43793331)

It is a quantum computer only when no one is looking at it.

Re:Is any quantum computer really quantum? (4, Funny)

K. S. Kyosuke (729550) | about a year ago | (#43793793)

It is a quantum computer only when no one is looking at it.

That sounds like the invasion of Weeping Turings...

Re:Is any quantum computer really quantum? (0)

Anonymous Coward | about a year ago | (#43793969)

Quantum existentiality.

Re:Is any quantum computer really quantum? (1)

Jeremi (14640) | about a year ago | (#43794039)

Has a D-Wave quantum-nature?
This is the most serious question of all.
If you say yes or no,
You lose your own quantum-nature.

D-Wave's Dirty Little Secret (5, Funny)

Greyfox (87712) | about a year ago | (#43793289)

Their computer works not by quantum entanglement but by magic.

Re:D-Wave's Dirty Little Secret (0)

Anonymous Coward | about a year ago | (#43793369)

Same thing, two names.

Re:D-Wave's Dirty Little Secret (-1)

Anonymous Coward | about a year ago | (#43793451)

well, one of them is real, the other isn't so they can't be the same thing.

Re:D-Wave's Dirty Little Secret (3, Informative)

flayzernax (1060680) | about a year ago | (#43795067)

One is a bunch of mathematical equations modeling a universe.

Math is not real. The models are not real. They are virtual.

Not saying that quantum mechanics doesn't have some robust models. But it is not "real" in an empirical sense. It is also not complete.

Re:D-Wave's Dirty Little Secret (2)

flayzernax (1060680) | about a year ago | (#43795073)

Simply put any math we use only defines a simulation. You only get real when you observe things. Which QM takes extreme issue with =p

Re:D-Wave's Dirty Little Secret (5, Insightful)

RevDisk (740008) | about a year ago | (#43793459)

Is there really any difference between quantum entanglement and magic?

Re:D-Wave's Dirty Little Secret (2, Funny)

Anonymous Coward | about a year ago | (#43793537)

Is there really any difference between quantum entanglement and magic?

You may have to ritually sacrifice the occasional intern to keep magic working, but otherwise, no.

Re:D-Wave's Dirty Little Secret (0)

Anonymous Coward | about a year ago | (#43793607)

If you haven't taken at least the second year of undergraduate quantum mechanics, or studied the equivalent content independently, then it's going to be hard to understand entanglement. It'd be like saying "Lie algebras are magic" when you don't know anything about topology. Quantum is hard, but so is everything.

Re:D-Wave's Dirty Little Secret (5, Interesting)

JoshuaZ (1134087) | about a year ago | (#43793677)

Is there really any difference between quantum entanglement and magic?

Yes. There's this tendency to view entanglement as spooky, magical, and hard to understand. But this really isn't the case and is more due to the confusing way that quantum mechanics if often taught, as a series of counterintuitive results tacked on to classical physics. If one adjusts one's perspective to think of quantum mechanics more as the consequences of using a 2-norm and looking then at the structure imposed on vectors by unitary transformations, things make a lot more sense. Scott Aaronson(mentioned in the summary above) has a book out recently on just this subject "Quantum Computing since Democritus" which is aimed at explaining these issues to people outside is field but with a comfortable background in other technical fields- essentially no more than some linear algebra, basic probability and complex numbers. The book is highly readable and Scott is a very funny writer, so there are a lot of amusing asides.

Re:D-Wave's Dirty Little Secret (3, Funny)

Anonymous Coward | about a year ago | (#43794631)

>using a 2-norm and looking then at the structure imposed on vectors by unitary transformations

Like, obviously!

Re:D-Wave's Dirty Little Secret (2, Insightful)

Anonymous Coward | about a year ago | (#43794785)

" If one adjusts one's perspective to think of quantum mechanics more as the consequences of using a 2-norm and looking then at the structure imposed on vectors by unitary transformations, things make a lot more sense."

Which means absolutely nothing to the vast majority of people; hence spooky, magical and hard to understand.

Re:D-Wave's Dirty Little Secret (2)

Comrade Ogilvy (1719488) | about a year ago | (#43795381)

I think my mathematics and quantum physics are not bad (although it were genuinely strong, perhaps I would have gone further than ABD), and I have trouble making "a lot more sense" of "using a 2-norm". Yes, I understand that the wave functions are complex, but that is not enlightening without a lot of math.

Most "spooky" results are simply the result of not accepting that everything is a wave form, and waves cannot understand that they are not supposed to be stretched across space. Which is another way of saying that JoshuaZ is correct about QM, unfortunately, being taught as "a series of counterintuitive results tacked on to classical physics". Pity.

(I would note that the QM as variance from Classical Physics can be sensible, but only if you deeply understand statistical physics at a level that is not usual even for physics PhDs.)

Our brains have evolved to feel comfortable with classical physics. When friends/family ask about exotic physics (QM or Relativity), I tell them: "The reason you are finding it implausible is your brain is working correctly; the sense comes from building up abstractions carefully with mathematics, motivated by precise experiments, that is completely outside everyday experience."

Re:D-Wave's Dirty Little Secret (1)

Eowaennor (527108) | about a year ago | (#43793761)

"Any sufficiently advanced technology is indistinguishable from magic" -Arthur C. Clarke

Re:D-Wave's Dirty Little Secret (0)

Anonymous Coward | about a year ago | (#43795299)

"Any sufficiently advanced marketing is indistinguishable from B.S." - me.

Re:D-Wave's Dirty Little Secret (0)

Anonymous Coward | about a year ago | (#43793979)

Obligatory:
Any sufficiently advanced technology... is indistinguishable from magic.
Any sufficiently advanced mind... is indistinguishable from insanity.
Any sufficiently controversial statement... is indistinguishable from trolling.
Any sufficiently advanced playing... is indistinguishable from cheating.

Re:D-Wave's Dirty Little Secret (0)

Anonymous Coward | about a year ago | (#43793709)

Only Apple devices work by magic.

Scientifically accurate product names not required (0)

Anonymous Coward | about a year ago | (#43793321)

"what's in a name?" Nothing.

Not General Purpose (1)

Anonymous Coward | about a year ago | (#43793465)

It's a quantum adiabatic solver, not a quantum (general purpose) computer. Anyone remember analog computers? Wickedly fast for the problem they were designed to sold, and not worth much doing anything else. D-Wave's machine is in the same category; if you want to solve a particular type of optimisation problem, you can run it on a D-Wave at quite some speed. If you aren;t looking to solve this class of problem, and/or cannot directly and efficiently transform your problem into this, then the D-Wave is useless to you. Additionally, like single-purpose computers past, the D-Wave will be rapidly made obsolete by more generalised computation (and unless D-Wave can keep updating rapidly to keep pace, by classical computation).

Re:Not General Purpose (3, Interesting)

gestalt_n_pepper (991155) | about a year ago | (#43793575)

But doesn't this suggest that arrays of narrow domain analog computers of this type might be constructed in such a way as to produce a *really* fast general purpose supercomputer? For example, sorting routines are built into most software frameworks. Could we not hybridize a system wherein np hard problems are called from the framework that transfers the sort to an quantum adiabatic solver and returns an answer?

Re:Not General Purpose (4, Informative)

JoshuaZ (1134087) | about a year ago | (#43794053)

There are a lot of problems wit this idea. Among other issues, quantum computers, even general purposes quantum computers, cannot as far as it is known solve any NP-hard problem in polynomial time. It is strongly suspected by people in the field that BQP (roughly speaking the set of problems easily solvable on a quantum computer http://en.wikipedia.org/wiki/BQP [wikipedia.org]) does not contain NP. There are also a variety of problems which are conjectured to be intermediate between P and NP which do not have known BQP algorithms. The set of things where a quantum computer can provide a lot of speed up is as of right now, highly specialized. That said, the long-term plan isn't that far off of what you are talking about, using general purpose classical machines to do most computations and only call the quantum computer when one has a problem of a specific type that substantially benefits from it (either from a drop into polynomial time from worse than polynomial time, or just a massive polynomial speedup).

Re: Not General Purpose (0)

Anonymous Coward | about a year ago | (#43794113)

Read up on their architecture. It essentially does this, using both a classical master and a quantum slave.

Re:Not General Purpose (1)

AC-x (735297) | about a year ago | (#43794477)

if you want to solve a particular type of optimisation problem, you can run it on a D-Wave at quite some speed

Except, according to the blog post linked, the D-Wave has so far been slower than optimised algorithms running on classical computers...

It's much cooler if we *don't* know how it works. (1)

gestalt_n_pepper (991155) | about a year ago | (#43793489)

Then we not only get a useful machine, we eventually get new science in the bargain. I *like* it!

Re:It's much cooler if we *don't* know how it work (0)

Anonymous Coward | about a year ago | (#43793719)

Um, you realize they claim to have engineered this thing? It wasn't described to them in a dream.

Re:It's much cooler if we *don't* know how it work (5, Interesting)

gestalt_n_pepper (991155) | about a year ago | (#43794121)

Anything can be pushed to the limits of what we know, and on occasion, things work, but not for the reasons you think it did. This is sufficiently close to the cutting edge that it may be operating correctly, but that we only think we understand why.

F'rinstance, for years, we thought about electricity as a liquid. Voltage equaled pressure. Amps equaled volume. The math worked. Nature wiggled it's eyebrows suggestively.

BUT, electricity is NOT a liquid. It works the way it does for completely different reasons. It just took a while for us to figure that out. Yet, even before we understood this, we build practical machinery.

Pay no attention to the man behind the curtain! (0)

Anonymous Coward | about a year ago | (#43793503)

Yeah, sure.

schrodinger's cat (0)

Anonymous Coward | about a year ago | (#43793527)

The problem here is that the processor is bot simultaniously on and off at the same time, much like a cat in a box. The only way to tell is time, eventually something will start to smell funny.

it is and it isnt (5, Informative)

nimbius (983462) | about a year ago | (#43793559)

the machine is really just a quantum annealer. you still need real computers to do your solving for things like computational quantum thermodynamics but where the D-Wave comes in, its really just there to assist the solver cluster with a more terse or efficient algorythm. Not bashing it, seeing as some of their jobs run months or years if the D-Wave manages to carve 20-30% off the time of a solver run, then you just saved ~80 days of work.

as to naysayers who think D-Wave isnt in a true quantum state, heres a research paper on the matter http://arxiv.org/abs/1304.4595 [arxiv.org]
Simulations of quantum versus classical annealers show that a classical one has a fairly uniform probability of solving a problem correctly; a quantum device should instead have a low probability of success at solving hard problems, and a high probability of success solving easy ones. This is what D-Wave is shown to do.

disclosure: i work for a large engineering firm that handles computational fluid thermodynamic and finite element analysis simulation as a service. Id be speechless to have one of these ajacent to my datacenter.

Re:it is and it isnt (4, Informative)

JoshuaZ (1134087) | about a year ago | (#43793727)

This is the sort of thing where it helps to read Scott's post. He specifically discusses the primary claim here:

Namely, the same USC paper that reported the quantum annealing behavior of the D-Wave One, also showed no speed advantage whatsoever for quantum annealing over classical simulated annealing. In more detail, Matthias Troyer’s group spent a few months carefully studying the D-Wave problem—after which, they were able to write optimized simulated annealing code that solves the D-Wave problem on a normal, off-the-shelf classical computer, about 15 times faster than the D-Wave machine itself solves the D-Wave problem! Of course, if you wanted even more classical speedup than that, then you could simply add more processors to your classical computer, for only a tiny fraction of the ~$10 million that a D-Wave One would set you back.

Re:it is and it isnt (0)

Anonymous Coward | about a year ago | (#43795209)

As an HPC guy anytime i see the phrase "You can simply add more processors to it" its usually bad news unless it accompanies a lengthy explanation as to why.

Re:it is and it isnt (0)

Anonymous Coward | about a year ago | (#43793889)

Id be speechless to have one of these ajacent to my datacenter.

Because of NDAs, no doubt.

Computer. (1)

DarthVain (724186) | about a year ago | (#43794729)

The problem is calling it a "Computer", which it is not really.

A better analogy might be to call it a like on some old school computers, a math co-processor. A math co-processor wasn't a "computer" but rather a processor that offloaded certain tasks that it could handle more efficiently.

I see this as a similar situation. It is really only good at solving very specific problems, outside of which a normal computer would be better served.

Quantum Schmantum (0)

Anonymous Coward | about a year ago | (#43793595)

That's what I say, about everything quantum.

Entanglement isn't the only issue (4, Insightful)

JoshuaZ (1134087) | about a year ago | (#43793613)

Scott's blog post and the comment thread there are really worth reading. Entanglement isn't the only issue. A major part of this also is whether the process that the D-Wave machine is doing is anything that is even faster (either in practice or asymptotically) than a classical computer. Right now, the answer for the first is clearly no. Scott describes mildly optimized systems which have been shown to effectively outperform D-Wave at its own problem. The second question- of asymptotic performance is a little trickier but the answer looks like "probably not". It is also worth noting that the D-Wave machines do a very specific optimization problem, of unclear usefulness, and cannot be used at all for many of things that we think of as what one wants a quantum computer for, like Shor's algorithm http://en.wikipedia.org/wiki/Shor's_algorithm [wikipedia.org] to factor integers.

In fairness to D-Wave though if one thinks of this as essentially a research machine, then not doing as well as conventional systems isn't that much of mark against it any more than very early cars being slower than horses. However, D-Wave is trying to sell these machines commercially. And Scott expresses worry that there's going to be a serious backlash against quantum computing as a whole when the the D-Wave hype bubble bursts. Apparently, D-Wave has now gotten about 100 million in funding, so at least, this is an extremely suboptimal allocation to resources when much more promising academic quantum computer research projects are getting much less money.

Re:Entanglement isn't the only issue (2)

MozeeToby (1163751) | about a year ago | (#43794095)

However, D-Wave is trying to sell these machines commercially. And Scott expresses worry that there's going to be a serious backlash against quantum computing as a whole when the the D-Wave hype bubble bursts.

No one with the money to afford one of their machines is stupid enough to buy them as anything other than a research machine. Even if someone hadn't come up with a way to match their speed with a classical computer (which has already happened) a 10,000x speed increase on a very narrow problem set at a cost of more than 100,000x just buying the additional hardware (not to mention the cost in learning how to use this new and exotic machine) makes obvious that it is not yet an economical solution for anyone.

Re:Entanglement isn't the only issue (4, Interesting)

Anonymous Coward | about a year ago | (#43794397)

I would argue that we should be open-minded at first and see what they can actually do. Maybe analog computers are in fact not as outdated as some people claim. Maybe we could build some sort of "analog FPGA" and do massively useful things with that. I still remember an HP computer graphics subsystem using analog computers !

Surely digital computers have the advantage of simple control of temperature, aging and general error margin issues, but it comes at a massive cost in the number of transisitors to perform a certain function. less than ten transistors can perform an analog multiplication while you need tens of thousands if not hundreds of thousands of transistors to perform a floating point multiplication. Also, the analog multiplier will be operating at much higher speed (easily 10x). Again, if we could control temperature and aging-related issues and have high integration and programmability (FPGA-style), maybe we could do massively useful things at very low power levels or with massive parallelity. I do NOT think that analog computers are dead forever. It might be more of a cultural thing we currently don't use them much ("digital is always better", "digital is modern" and similar semi-truths.

If you put one seasoned computer scientists and one seasoned electrical engineer in one room and task them to do what I described, if you give them massive funding (say 3 million dollars), I am sure they could come up with something massively useful. For example, digital circuits could periodically calibrate the analog circuits to compensate for all kinds of drift and aging. Software could automate the drudgery of manual circuit synthesis, it could model crosstalk and similar things.

Well, maybe Analog Devices already has this kind of thing.....

Re:Entanglement isn't the only issue (1)

Anonymous Coward | about a year ago | (#43794451)

Also, nobody dictates we can't combine digital functions with analog ones. To store a signal and replay it later, ADCs, SRAM and DACs are of course the "go-to" solution. We can mix and match that with analog multipliers, filters, OpAmps, logarithmic circuits and so on. If the noise from an analog circuit becomes too strong, we can digitize the signal and "clean it up" using a DSP.

Progress comes from free thinking, not from formal or informal dogma !

Mod parent up (1)

meza (414214) | about a year ago | (#43794663)

Damn. All those mod points last week, and now when I for once run in to an under-moded AC post, of course I have non. I would love to read a comparison between the D-Wave computer and analog computers.

Re:Entanglement isn't the only issue (1)

Impy the Impiuos Imp (442658) | about a year ago | (#43794213)

It is useful as a first generation experiment. Only in comic book land does it take off whizzing.

And then shortly it comes alive, with evil intent. No, no! Don't go after Lois Lane! The writers will never let you win in the end!

If you want to force Ant Man to rape Plasic Man's wife in the meantime, I guess that's OK.

Proved the Market (4, Interesting)

bill_mcgonigle (4333) | about a year ago | (#43793671)

Whether this thing turns out to be the real McCoy (dammit Jim, I'm a quantum annealer) or not, one thing D-Wave has done is proven that there are customers who will pay $10M to be on the cutting edge of quantum computing for a few years. This should help boost investment and entrepreneurship in other companies. Eventually, one of them will revolutionize everything.

Re:Proved the Market (2)

oh_my_080980980 (773867) | about a year ago | (#43793749)

The only thing they proved is there's a sucker born every minute. It has not helped the field of quantum computing. In fact it set it back because now people are going to distrust something that's called a quantum computer.

Quantum/Non Quantum (0)

Anonymous Coward | about a year ago | (#43793781)

According to the EULA, it is both quantum and non quantum. But if you examine it to determine if it is quantum, then it isn't quantum anymore.

I need more evidence! (2)

FilmedInNoir (1392323) | about a year ago | (#43793963)

D-Wave is probably a scam, but I work in IT, almost the entire industry is built on scams.
Scott Aaronson comes off as an egotistical man-child that is just angry he's not directly involved in all this.
It's still love - love in this match.

Re:I need more evidence! (0)

Anonymous Coward | about a year ago | (#43794501)

Well, capitalist scammers have destroyed communism with their lies and efficiency. Maybe it is sometimes useful for economic progress to hide the truth. Would you want to know how they treated that animal, how they processed the meat which you eat with your burger ? It is probably much more efficient for everybody if you don't know that. You would be distracted from creating massive amounts of highly buggy, but shiny software, you know.

Captcha: Lavatory. Hey, Slashdot folks, you are very small-minded....

Genuine Quantum computers... (1)

Anonymous Coward | about a year ago | (#43794145)

come with a "tiddles inside" logo on them.

Here is proof it is a scam (0)

TheSkepticalOptimist (898384) | about a year ago | (#43794377)

Straight from the website:

"Our latest superconducting 512-qubit processor chip is housed inside a cryogenics system within a 10 square meter shielded room."

So in other words, we have a quantum computer, you just can't SEE the quantum computer.

lol, one of the applications of this "quantum computer" is to identify if there is a car in a series of pictures, you just need to hire a couple of Chinese undergrads to sit in that 10 square meter room and hit a yes or no button as they are stream a bunch of images with or without cars.

Stupid Question of the Day!!!! (2)

Xaedalus (1192463) | about a year ago | (#43794443)

Now that I've RTFA and through the commentary threads, as a dumb ignorant layperson I get why Scott Aaronsen is right to call out D-Wave. I also get the counter-argument that there needs to be some sort of hype in order to sustain interest in QC. And, the damn thing's got to work eventually. What I'm wondering though is this: Are we (as a society) making an error in trying to use QC to solve problems that are particular to classical computing?

The reason I ask is that a while back on /. I was educated about the nature of Base-10 computing. Prior to this, I'd spent my entire life thinking that Base-10 WAS mathematics, and I'd had no reason to assume or even imagine that there could be any other type of mathematics than Base-10. Base-10 was the pinnacle of mathematics to me. Then I find out that Base-10 is probably the most efficient to date for our society, but that it is not the only way to count; and that Pi is only Pi because of Base-10. Which led me to look at mathematics in a whole new light. Similar with Quantum mechanics--the more I understand about Quantum Mechanics, the more I realize that I have to set aside everything I know about Newtonian physics, because trying to understand quantum physics from a newtonian perspective will always result in failure--while there is a bridge between the two, if I don't take that "bridge" into account then I'm metaphorically trying to judge apples based on my prior experience in dog shows.

Given this, is it fair to hold QC to the same standards as Classical Computing, or should we be looking at entirely new applications of computing? And, is there anyone out there who's staring into the vast unknown and saying "What happens if we do THIS with a QC?"

Re:Stupid Question of the Day!!!! (3, Informative)

JoshuaZ (1134087) | about a year ago | (#43794551)

he reason I ask is that a while back on /. I was educated about the nature of Base-10 computing. Prior to this, I'd spent my entire life thinking that Base-10 WAS mathematics, and I'd had no reason to assume or even imagine that there could be any other type of mathematics than Base-10. Base-10 was the pinnacle of mathematics to me. Then I find out that Base-10 is probably the most efficient to date for our society, but that it is not the only way to count; and that Pi is only Pi because of Base-10.

No. Pi will be the same regardless of base. The digits of Pi will be different if you write it in a different base, but this is simply a representation, not a change in what the number is. If you do calculations involving Pi in one base and do the same thing with another base and then convert the answer from one to the other you will get the same thing.

Your general question is a good one. In fact, one of the major things people want to use quantum computers for is to do simulations of quantum systems, which they can do, but which are extremely inefficient (both in terms of time and memory) on a classical computer. So people are looking at problems which are practically not doable on a classical computer. At the same time though, we know that a quantum computer can be simulated on a classical computer with massive resource overhead (essentially exponential slowdown), so we know that anything you can do on a quantum computer you can do on a classical computer if one is patient enough.

Re:Stupid Question of the Day!!!! (1)

arth1 (260657) | about a year ago | (#43795285)

Then I find out that Base-10 is probably the most efficient to date for our society, but that it is not the only way to count; and that Pi is only Pi because of Base-10.

No, pi is pi in all bases equal to or higher than two, provided you assume euclidian geometry.
If you meant that pi is 3.14159265358979323846... only because of base 10, you're correct (again, as long as you ignore relativity and curved space).

Problem Specific Computer (0)

Anonymous Coward | about a year ago | (#43794457)

One of the members of the D-Wave team gave a talk at a physics conference I attended in October. One of the questions was related to why their strategy for quantum computing was so different than other more academic teams. Their answer effectively stated that their system is problem specific with effectively a new hardware setup required for each new problem, while a "true" quantum computer would function like a regular computer.

Re:Problem Specific Computer (0)

Anonymous Coward | about a year ago | (#43794539)

There are plenty of people in crappy-looking clothes with deep pockets who have massive funding available if you can solve one of their problems. Or if you can convince them there is a "grap", then they will probably fund you regardless of the usefulness of your invention. Don't worry about that.

The whole universe is Quantum (1)

bigsexyjoe (581721) | about a year ago | (#43794715)

Of course it is quantum. The whole universe, including the reactions in the D-Wave are based on the laws of quantum mechanics. Regular computer chips have to take quantum effects into account too, although they try to defeat quantum effects rather than utilize them. Nevertheless, at a basic level the transistors work because of the laws of quantum mechanics.

So how do you want to describe the D-Wave? Do you want to describe it using the laws of Quantum Mechanics? Or do you want to approximate it using a classical model that is carefully chosen to not get the quantum effects wrong?

In either case, as the article says, it's still fast.

What? (2)

jones_supa (887896) | about a year ago | (#43795063)

They can build these things already? I thought that quantum computers would be only a theoretical idea for many coming years.

Re:What? (0)

Anonymous Coward | about a year ago | (#43795195)

Read the fine summary! Wether it is quantum or not and to which point is precisely what's under discussion.

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