Slashdot Mirror

← Back to Stories (view on slashdot.org)

Quantum Computer Demoed, Plays Sudoku

Posted by kdawson on from the more-qubits dept.

prostoalex writes "Canadian company D-Wave Systems is getting some technology press buzz after successfully demonstrating their quantum computer (discussed here earlier) that the company plans to rent out. Scientific American has a more technical description of how the quantum computer works, as well as possible areas of application: 'The quantum computer was given three problems to solve: searching for molecular structures that match a target molecule, creating a complicated seating plan, and filling in Sudoku puzzles.' Another attendee provides some videos from the demo." Anyone want to guess how long before "qubit" gets compressed to "quit" (as "bigit" became "bit" in the last century)?

59 of 309 comments (clear)

  1. Traveling Salesman by Short+Circuit · · Score: 5, Interesting

    Does this mean we'll be able to solve the Traveling Salesman problem soon? That would lead to a revolution in efficiency of everything from travel to mass transit to shipping.

    I imagine the USPS and other shipping organizations will be the first to buy commercial versions of these.

    --
    tasks(723) drafts(105) languages(484) examples(29106)
    1. Re:Traveling Salesman by TorKlingberg · · Score: 3, Insightful

      There are fast and almost-exact algorithms for Traveling Salesman problem that are good enough for practical purposes.

    2. Re:Traveling Salesman by Anonymous Coward · · Score: 2, Insightful

      I think you've missed the point of the Traveling Salesman problem. It's a theoretical mathematical exercise, not a practical issue in mass transit or shipping. The important bit is that we could solve all sorts of other, more interesting problems if we could solve that one.

    3. Re:Traveling Salesman by Ed+Avis · · Score: 4, Interesting

      Nobody is going to use Travelling Salesman in the real world to plan journeys. You can already quickly run an algorithm which will get you a journey plan that's maybe 99% as good as the optimum. Besides, real things (even salesmen) don't just have to travel in straight lines between points in space. There are other factors like lunch breaks and the location of good restaurants, which the problem doesn't account for.

      Travelling Salesman is NP-hard, which means (I think) that if you find a polynomial time algorithm for it, any problem in NP can be done in polynomial time (hence P=NP). But I believe that even this quantum computer can't calculate TSP in polynomial time, except for instances small enough to fit inside the 16-qubit memory. Can anyone comment on this? By contrast, a conventional computer can always calculate TSP in the same time complexity (exponential time) no matter how large the input - you just have to hook up enough memory.

      --
      -- Ed Avis ed@membled.com
    4. Re:Traveling Salesman by Zdzicho00 · · Score: 3, Funny

      I think that it will solve the Traveling Salesman problem of course (find best possible path for salesman).
      Unfortunately it shall to be run by salesman before every travel - so it isn't very useful.

      /Z
    5. Re:Traveling Salesman by gazbo · · Score: 4, Informative

      Even if you could solve TSP in polynomial time on a quantum computer, it still wouldn't show that P=NP as the machine would be nondeterministic. The goal of quantum computers is to sidestep the NP issue, not reduce it to P.

    6. Re:Traveling Salesman by Anonymous Coward · · Score: 4, Informative

      You are pretty much correct--traveling salesman is NP-hard and most theorists believe that BQP, the class of problems efficiently solvable by a quantum computer in polynomial time, is strictly smaller than NP (and therefore contains no NP-complete problems). This is, of course, not shown--for all we know, it could even be strictly bigger than NP. The evidence is that the only two problems quantum computers can solve in polytime right now that a turing machine can't are integer factorization and discrete log, neither of which is believed to be NP-hard.

      BTW, of course a problem instance must fit in memory--but the idea is that we should be able to build a 1000 qubit computer, while going through 2^1000 possibilities to brute-force a problem of size 1000 is intractable. But with our knowledge now, even if you fit a traveling salesman instance, the quantum computer wouldn't know what to do with it.

      As GP pointed out, we do have excellent approximations for TSP and most practical problems--the issue is mathematical--that we don't have algorithms that can guarantee the absolute best solution. The one place quantum computers are potentially useful is crypto--nearly all of which revolves around the hardness of factoring and discrete logs (which I think is a very strange coincidence, if it is one).

    7. Re:Traveling Salesman by hotdiggitydawg · · Score: 5, Informative

      all a Sudoku puzzle is, at it's core, is a depth first search. Which is not an algorithm that runs in polynomial time. It is a DFS of all (legal, remaining) permutations, which is an exponential number.

      even on a moderately fast PC a DFS is fast enough to get a solution to a Sudoku puzzle in the blink of an eye. Regardless of how easy a 9x9 grid seems, Sudoku is still at its core an NP Complete (PDF warning) problem. Why is it therefore any less valid than any other NP complete problem? Travelling Salesman is also pretty easy with less than 10 nodes... likewise you can feasibly crack any encryption scheme by brute-force if you constrain it to have a tiny key size. It's all about scale.

      The beauty is, if you solve any NPC problem you solve them all, by definition. So, Mr. Smarty Pants, if your Sudoku solver is good enough to solve any grid in polynomial time, please show the rest of us, as you've just cracked every encryption scheme invented to date.

      Yeah, I didn't think so.
    8. Re:Traveling Salesman by amper · · Score: 3, Funny

      Besides, real things (even salesmen) don't just have to travel in straight lines between points in space. There are other factors like lunch breaks and the location of good restaurants, which the problem doesn't account for.

      Which, of course, clearly demonstrates the utility of the Bistro Drive for all Traveling Salesmen.

    9. Re:Traveling Salesman by Anonymous Coward · · Score: 2, Funny

      Challenge accepted. I will have a 1,000,000 x 1,000,000 sudoku problem available for your quantum computer soon. Care to place a wager on this before I present you with the grid?

    10. Re:Traveling Salesman by fishbowl · · Score: 3, Funny

      "I was taking Steven Cook's Complexity Theory class at UofT and when we were given the TSP I immediately saw a solution reduced into Dijkstra's algorithm. I don't think anyone in the class actually followed, the prof said that it can probably work. I never dealt with it again, but that was the reason I remember that class."

      Did you at least try to scribble it in the margin of your book?

      --
      -fb Everything not expressly forbidden is now mandatory.
    11. Re:Traveling Salesman by nasch · · Score: 5, Funny

      So, Mr. Smarty Pants, if your Sudoku solver is good enough to solve any grid in polynomial time, please show the rest of us, as you've just cracked every encryption scheme invented to date.
      As the CS gangsta rapper MC++ put it, "if we could factor large composites in poly time, we'd have enough money to not have to rhyme."
    12. Re:Traveling Salesman by ebvwfbw · · Score: 2, Interesting
      Nobody is going to use Travelling Salesman in the real world to plan journeys.

      Sure they do. School systems do this for bus routes. Some counties used to pay good money for that. For one school system I worked with it saved nearly 1 million in gasoline for the year and that school system wasn't that large and back then gasoline wasn't that expensive like it is now. The next year I suggested changing school start times to optimize it even further. They saved an additional 3 million that year and eliminated a number of busses entirely. This is just one example.

      BTW, even though they don't travel in straight lines in practice, that doesn't matter. Simply consider the mileage as a line. After all they are confined to the road unless they have off-road capabilities.

      Even the average Joe often does the TSP, probably without realizing it. When you have a number of places to go, do you just go to whichever first or do you plan your journey to optimize your time? Almost everyone I know figures this out before they leave. Sometimes if there is a group of us, I have even observed discussions on which routes and order would be best.

    13. Re:Traveling Salesman by tbo · · Score: 4, Interesting

      Disclaimer: I am a physicist who works on quantum computing and also has a computer science background

      Nobody is going to use Travelling Salesman in the real world to plan journeys. You can already quickly run an algorithm which will get you a journey plan that's maybe 99% as good as the optimum.

      Actually, I think there is a theorem that finding an algorithm that efficiently produces highly-accurate approximate solutions to arbitrary problems in NP-hard is about as hard solving NP-complete problems exactly.

      All this aside, it's worth noting that D-Wave is only claiming to provide a square-root speed-up for NP-complete problems, and there is some doubt as to whether they can even deliver that, as they scale up to larger numbers of quantum computers. While it's technically possible that P=NP, most people believe P!=NP, and it seems almost as likely that BQP != NP (BQP is the class of problems efficiently solvable with a quantum computer).

      For an excellent discussion of what D-Wave has done and just how skeptical you should be, visit Scott Aaronson's blog. (No, I am not Scott Aaronson, but I do know him and can vouch for him being an extremely smart guy. I am also not the Quantum Pontiff, aka Dave Bacon.)

    14. Re:Traveling Salesman by GBladeCL · · Score: 2, Informative

      What are you talking about? DFS is only linear in the best case where the solution is on the first branch. If the depth of the tree is d then at the worst case you will have to search every node which would be 2^(d+1) - 1 nodes. That's exponential time.

    15. Re:Traveling Salesman by DusterBar · · Score: 4, Insightful

      The first digital computer systems did not solve anything "amazing" but the fact that they solved anything at all was the amazing bit.

      Quantum computing is very new (in the physically exists sense) and the fact that they figured out how to build, program, and extract the solutions for some, albeit relatively simple, problems is a major step forward.

      Once the understanding is complete enough and reliable enough then the really tough problems will be sure to follow.

  2. Nope by Anonymous Coward · · Score: 4, Funny

    "Anyone want to guess how long before "qubit" gets compressed to "quit" (as "bigit" became "bit" in the last century)?"

    Nope.

    http://myspace-271.vo.llnwd.net/00407/17/24/407284 271_s.jpg

  3. BIGIT?? by CmputrAce · · Score: 5, Informative

    Never heard of one (bigit). I have, however, heard of the "binary digit" that was shortened to "bit". Given that history, "qubit" is short for "quantum binary digit" - which is an oxymoron since quantum digits can be any (or all) of several states, not just on or off (binary). A more accurate acronymish shortening would be "quigit" - which sounds awkward enough to be shortened to "qit", (pronounced KIT rather than QUIT to avoid confusion).

    I think "qubit" is here to stay, though.

    1. Re:BIGIT?? by HTH+NE1 · · Score: 4, Funny

      Only if four of them is a quibble.

      --
      Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
    2. Re:BIGIT?? by cellocgw · · Score: 4, Funny

      "qit is better."

      I vote for "qute," pronounced like the way you'd describe your girlfriend if you had one.

      --
      https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
    3. Re:BIGIT?? by Eudial · · Score: 3, Funny

      The metric system is the tool of the devil! My car gets forty rods to the hogshead, and that's the way I likes it!

      --
      GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
    4. Re:BIGIT?? by Dirtside · · Score: 2, Funny

      I guess eight would be a qubits would be a quite. Quite what, I'm not sure.

      --
      "Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
    5. Re:BIGIT?? by julesh · · Score: 2, Funny

      The metric system is the tool of the devil! My car gets forty rods to the hogshead, and that's the way I likes it!

      Jesus, you should start looking for a fuel leak.

    6. Re:BIGIT?? by DavidTC · · Score: 2, Insightful

      I don't know what you're trying to get across, but you're either wrong or not explaining it well.

      Qubits are are not just bits. Qubits are bits in a quantum superposition, and as such do not 'assume' a state from zero to one, but are, instead, all such states at once(1), just like the GP said. (Or all such states in different universes, if that's the interpretation that floats your boat.)

      The probability may be writable by physicists, but the actual state of a qubit isn't. (At least not before the calculation is over and it is measured.)

      That isn't something that's mildly important, that's how qubits work. Once we actually have multi-qubit quantum computing, and possibly this is going on in this machine, the qubits won't hold 'all' states, but instead specific patterns of states, with different areas being different probabilities. Like interference pattern in a two-slit experiment, where there are likely areas (well-lit), unlikely areas (grey), and impossible areas (unlit). Qubits would 'interfere' with each other until only one (or a few) areas were lit (or dark), and that's the answer. Or, at least, close enough to the answer that a tiny bit of classical checking can nail it down.

      There's a quantitative difference between something that holds values that can be measured, and something that holds values that cannot. qubit!=bit

      --
      If corporations are people, aren't stockholders guilty of slavery?
  4. Sudoku: The np-easy version of Traveling Salesman by Anonymous Coward · · Score: 2, Interesting

    Actually you don't need the DFS.

    I've built a Sudoku program to help me reduce the boring parts (filling in the only posssible option if it is known). I didn't know that it would solve all boards except for the hardest ones.

    Then I've added another filter that still was not DFS and it solved all boards to this day except 2. One of which had 2 solutions and the second could be solved with a DFS of depth 1.

    Took all the fun out of the game.

    Some timing statistics: less than 1 second with Javascript on Firefox. About 30 seconds with Internet Explorer.

  5. Curious by vlad_petric · · Score: 4, Interesting

    I'm actually curious - for how long do the 16 qubits stay coherent? You can only do quantum computations while the qubits remain coherent. Furthermore, IIRC coherence times where (at best) in the range of a few microseconds.

    --

    The Raven

    1. Re:Curious by paeanblack · · Score: 5, Funny

      I'm actually curious - for how long do the 16 qubits stay coherent? You can only do quantum computations while the qubits remain coherent. Furthermore, IIRC coherence times where (at best) in the range of a few microseconds.

      That's why quantum computers will be so fast. If not, they will constantly forget... Damn. Where was I going with this?

  6. For real? by DurendalMac · · Score: 2, Interesting

    Is this a true quantum computer, or one that simply uses certain quantum properties? Scientists weren't predicting this for another 20-30 years. Wouldn't a 1024 qubit computer be far faster than any cluser on earth? And if I'm not mistaken, a 16 qubit computer would be faster than any single computer. I'd like to see some speed comparisons for parallel tasks.

    1. Re:For real? by jason8 · · Score: 5, Informative
      Apparently not a true quantum computer. From a wired news article:

      D-Wave held its first public demonstration Tuesday of a machine it claims uses quantum mechanics to solve a certain type of problems, such as searching a database for matching molecular structures.

      But the company did not make the machine available for inspection and instead showed video from a remote location, saying it was too sensitive to be easily transported.

      And notwithstanding lofty claims in the company's press release about creating the world's first commercial quantum computer, D-Wave Chief Executive Herb Martin emphasized that the machine is not a true quantum computer and is instead a kind of special-purpose machine that uses some quantum mechanics to solve problems.

    2. Re:For real? by paeanblack · · Score: 2, Funny

      But for doing your taxes or playing Quake it would be completely useless.

      I'm not sure about that...I've heard rumors of IBM unleashing Deep Pwn upon the FPS world next year

  7. This isn't fair! by neo · · Score: 5, Funny

    I want to solve sudoku. Now some computer can do it so fast that it's finished before they even start? What good is that? Sudoku is supposed to be about wasting time, not reversing it.

  8. Or rather... by null+etc. · · Score: 3, Funny
    Anyone want to guess how long before "qubit" gets compressed to "quit" (as "bigit" became "bit" in the last century)?


    Anyone want to guess how long before hillbillies start asking "How many quberts you got in that there system?"

    1. Re:Or rather... by kabocox · · Score: 2, Interesting

      Anyone want to guess how long before "qubit" gets compressed to "quit" (as "bigit" became "bit" in the last century)?
      Anyone want to guess how long before hillbillies start asking "How many quberts you got in that there system?"

      I think qubert rolls of the tongue easier than qubit. Let's push qubert as the new way of saying qubit!

  9. Re:obligatory by Undertaker43017 · · Score: 2, Funny

    Not yet, give it a week.

    Of course it is a quantum computer, so maybe it's done already and we just don't know it, because every time we look at it, it changes.

    On the other hand it can only play Sodoku so far, so maybe not.

  10. Re:obligatory by j00r0m4nc3r · · Score: 5, Funny

    But... does it run Linux?

    It runs all possible operating systems at once, but once you type a command in the probability wave collapses and you're stuck using AmigaDOS.

  11. Here me son of man! by GodInHell · · Score: 5, Funny

    I come to warn you that there shall be a great outage.. go forth and build an array to save my creations. Make it 100 qubits long, 30 qubits wide, and 10 qubits deep. Into this hash all data in /usr/god/dataM/ .. and /usr/god/dataF/

    Do this, and you shall survive the outage I shall send.

    :D I can't resist a bad pun.

    -GiH

    1. Re:Here me son of man! by Apocalypse111 · · Score: 3, Funny

      Damn! You beat me to it! I was gonna post something like this myself, but the flood-protection was telling me to wait.

      --
      There is no mod option "-1: Disagree" for a reason. "Overrated" is not an acceptable substitute. Post something instead.
    2. Re:Here me son of man! by Grech · · Score: 2, Funny

      Flood protection. Isn't that ironic.

      --
      It may not be just, but it is fair, and that is more important.
  12. Re:Sudoku: The np-easy version of Traveling Salesm by pato101 · · Score: 2, Funny

    I've built a Sudoku program to help me reduce the boring parts (filling in the only posssible option if it is known)
    Wait, those are the boring parts??
    Took all the fun out of the game.
    I told you!

  13. breaking cryptopgraphy with Quantum computing by Danathar · · Score: 3, Interesting

    I wonder....

    If the NSA wanted to build a custom quantum computer to break traditional cryptographic systems what are the chances that's it's already been done (and in use)?

    Mass producing a commercially viable quantum computer (or many sci-fi like technologies) is usually pretty hard, but producing one or two special purpose built systems are MUCH easier.

  14. Common misconceptions by rbarreira · · Score: 5, Informative
    To save some work to people replying to misconceptions, here's a list of the common misconceptions about quantum computing that I've seen lately:

    • Quantum computers can solve NP-complete problems quickly (in polynomial time) -> not true, the speedup given by Grover's algorithm is quadratic, not exponential. This means that an NP-complete problem which would take O(2^n) in a classical computer would take O(2^(n/2)) in a quantum computer, which is clearly not polynomial time in n
    • Quantum computers with N qubits are as efficient as 2^N classical computers -> not true, not all algorithms can get an exponential speedup with quantum computing
    • Quantum computers will render cryptography useless -> not true, breaking asymmetric ciphers with QCs are subject to the quadratic speedup I explained above which means it will be enough to double the size of the key in order to account for QCs. Some symmetric ciphers (i.e. public key systems) are broken by quantum computing (for example RSA and discrete logarithm), but it is thought that there are some symmetric ciphers which are not vulnerable to attacks by QCs (excluding by the grover search algorithm, which as I explained above is not very hard to account for). Quite ironically, I remember reading that the same attack which renders discrete logarithm public key cryptography useless also allows for the existence of a public key encryption which requires fast calculation of discrete logarithms.
    --

    The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
    1. Re:Common misconceptions by khallow · · Score: 2, Interesting

      You ignore what is probably the source of the misconceptions, namely Shor's algorithm which solves integer factorization in O(N^3) time and O(N) space (where N is the log of the number to be factored). However, integer factorization probably is not NP-complete and no one has figured out how to recast in polynomial time an NP-complete problem as a factoring problem that the Shor algorithm can handle.

  15. [QUIT] vs [KIT] by DrYak · · Score: 3, Insightful

    "qit", (pronounced KIT rather than QUIT to avoid confusion).


    And to avoid the massive worldwide suicide of voice-recognition software who suddenly log-out the computer, in the mid of the dictation of some research paper...

    Dear aunt, let's set so double the killer delete select all.
    --
    "Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
  16. A bold leap forward in computing by Rob+T+Firefly · · Score: 5, Funny

    Immediately after booting, the Quantum Computer disappeared in a flash of light and noise. It resurfaced in 1985, where it briefly took over a Commodore 64 and corrected some mistakes it made the first time around, before moving onto a UNIVAC in 1955...

    --
    Slashdot Burying Stories About Slashdot Media Owned
  17. Oops by rbarreira · · Score: 2, Funny

    As you probably have learned, sqrt(2^n) is sqrt(2^(n/2)).

    Obviously that second sqrt() shouldn't be there, apologies (my original post is correct).
    --

    The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
  18. "Bigit" never existed. by caveat · · Score: 3, Informative

    Claude E. Shannon first used the word bit in a 1948 paper. He attributed its origin to John W. Tukey, who had written a Bell Labs memo in 9 January 1947 in which he contracted "binary digit" to simply "bit".
    No mention of "bigit", seems to have just been invented today.

    http://en.wikipedia.org/wiki/Binary_digit
    --

    Facts do not cease to exist because they are ignored. - Aldous Huxley
  19. More info... by Panaflex · · Score: 4, Informative

    Some more videos...
    High level explanation
    Protein matching
    Sudoku

    Also, here's some slightly older talk at Stanford with a higher-level audience

    Additionally, it's not exactly a "true quantum computer"(tm) - but it utilizes quantum mechanics as a quantum computer would. So it quacks like a duck, etc.

    --
    I said no... but I missed and it came out yes.
  20. Ask the companies founder - here's his blog: by RMH101 · · Score: 4, Informative

    Geordie Rose's blog: http://dwave.wordpress.com/

  21. Bill Cosby by sconeu · · Score: 4, Funny

    Lord, what's a Qubit?

    --
    General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
  22. Re:Sudoku: The np-easy version of Traveling Salesm by geoffspear · · Score: 2, Interesting

    They're not Sudoku.

    But of course they have solutions. Otherwise, you couldn't start with an empty 9x9 grid and create a Sudoku in it in the first place.

    In any case, solving the things is a much more trivial problem than creating valid ones or arbitrary difficulty. But the fact that seemingly hundreds of different publishers are out there creating books without any quantum computers at all is probably a good hint that nothing to do with Sudoku is a particularly impressive computational task to use to show how great your new quantum computer is.

    --
    Don't blame me; I'm never given mod points.
  23. Re:My suggestion for new tasks by Farmer+Tim · · Score: 5, Funny

    You don't want quantum computers anywhere near the Slashdot front page: it'll only lead to more accusations of spin.

    --
    Blank until /. makes another boneheaded UI decision.
  24. Re:obligatory by GodInHell · · Score: 5, Funny


    Dev: Ah.. finally got it up and..
    Linux: CRASH AND NOISE AND HORROR AND SCROLL SCREEN KERNEL DUMP!!
    Dev: .. stupid drivers.. grr..

    ||time passes||

    Dev: okay, this time.. it stays up..
    Linux: ...loading.. CRASH!! OH GOD MY SPLEEN! NOT MY HARD DRIVE!! OWWW!

    ||Five iterations later||

    Dev: Finally... now.. WORK!!
    Linux: ...loading.. Hello Dave, can I help you?
    Dev: Yes! Finally!! Tell me, what is the meaning of life, the universe, and everything!?
    Linux: Oh that's simple.. spending time with your wife and kids.
    Dev: What.. oh.. God.. NO!!!

    I like linux.. and I like jokes at linux.. go figure.

    -GiH

  25. The funny thing about quantum computing is... by Coco+Lopez · · Score: 3, Funny

    From what I understand, when you run Windows on a quantum computer it won't crash unless you look at it.

    Also, the last time I used a machine with qubits, I had a hard time keeping them from jumping off the friggin' pyramid.

    You've been great... I'm here all week... remember to tip your waiter.

  26. Re:P not necessarily NP by Anonymous Coward · · Score: 2, Funny

    My uncle did 20 years ago. Scientists won't acept the proof because he's black.

  27. kit by Tumbleweed · · Score: 2, Funny

    "qit", (pronounced KIT

    I don't think so, Michael.

  28. Re:Sudoku: The np-easy version of Traveling Salesm by MightyYar · · Score: 2, Insightful

    True, but crosswords always annoy me - half of what you need to know is useless trivia: "Rebel Without a Cause Co-Star"... who cares? Okay, yeah, I know it's Natalie Wood, but that's useless knowledge.

    --
    W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
  29. A classical (no quantum) case of milk and water.., by drolli · · Score: 2, Insightful

    and lots of smoke is there, too.

    Milk and water: take something which is new, but not be interesting scientifically, mix it with something old and dilute it. Shake it for some time. Smoke: Add nice words and senseless technological complications. Claim that your system (although you are doing basic reseacrh which could not be more of from implmenting that) will solve the problems of the world put in your own hand to choose the problem size you want to do this with (If you write for IEEE on Image Processing wou will also not choose a picture where your algorithm fails). Smoke is necessary if you want to use milk and water and cover up that the things you are mixing with are not very new.

    Disclaimer: I come from the field. Before I come to my critics, I have to say that I am impressed with DWave having this System developed in this way and I believe that something will come out, probably good research; and maybe eve a working QC.

    Regarding the talk of Dr. Geordie Rose:

    * he says, they have something but they do not want to compare it to the other approaches, which this time he at least gives an credit, claiming that the others try it differently. This is done to guide the audience away from topic of coherent entangement. I really miss an simple spectrocsopic measurement of their system or some of the things you can do in AQC.

    * And, please. As far as I understand the 128 Control lines are used for DC biasing of the coupling SQUIDS. I'd like to see a calculation of the influence of the 1/f noise of the Spectrum of the Hamiltonian for a realistic algorithm.

    * He claims that building a complex system out of things you don't understand and enhancing it is more promising than enhancing the single thing and composing it. He says they qould use a quick and dirty approach to it. He misses to mention that they are the only ones seriously doing so. (a fundamental issue about insulator materials used was found out, exactly because one of the leading groups examined a single qubit very careful)

    * He brings it into a subtle connection to a technology long existing (RSFQ, which is not used as far as i can see on DWaves chip and Dwave has not much to do with this technology - only that some people working previously on RSFQ now work there) and presents it as something where their research is useful for. This is done deliberatly to stun the audience who most likely have not heard of it. He says that superconductting computers are fast, but indeed the AQC itself is slow. How slow, depends on the algorithm which you use.

    * I would classify DWave as a hardware-company. Why all this glittering software around. For the people who want to use an QC it does not matter if you pack it nicely into an SQL server. Call me conservative and square, but somebody showing animations in a technological demonstration frontend has in 50% of the cases something to cover up.

    I understand that all this is necessary to impress possible investors. As a scientist I'd be more impressed about a cond-mat preprint where DWave describes the performance of the system in detail. Actually I can't expect it...

  30. Re:Sudoku: The np-easy version of Traveling Salesm by Intron · · Score: 4, Funny

    This is an example of using the wrong tool for the job.

    You should have written it as a Word macro.

    --
    Intron: the portion of DNA which expresses nothing useful.
  31. There is already a good solution by Peaker · · Score: 2, Informative

    There is already a P partial solution to the travelling salesman. It does not find the best path, but it is proven that it finds at worst a path that's twice as long.
    With a few heuristics, the worst case becomes very rare, and it usually finds something closer to the best solution.

    So if we solve the NP travelling salesman in a perfect way, at most we'll get paths that are half the length.
    That could be an improvement, but not a revolution.