Forgot your password?
typodupeerror
This discussion has been archived. No new comments can be posted.

Web Quantum Computer Simulator

Comments Filter:
  • by garcia (6573) * on Tuesday June 15, 2004 @01:58PM (#9432269) Homepage
    Wow, I really hope that they didn't put those 32 processors and 56GB of DDR RAM into use for this [fraunhofer.de]. Sounds like they should have read this [slashdot.org] article instead. Maybe it would have been cooler and not so grainy!
  • by Anonymous Coward on Tuesday June 15, 2004 @02:00PM (#9432301)
    The algorithm in psuedo-code:

    int qbit[32];

    for ( i = 0; i < 32; i++ )
    qbit[i] = (rand() >>30) & 0x01;


  • Nice rack. (Score:5, Funny)

    by Anonymous Coward on Tuesday June 15, 2004 @02:00PM (#9432309)
    Nice rack, seriously. Clean, uncluttered.
    • by avgjoe62 (558860)
      Nice rack, seriously. Clean, uncluttered.

      It is a sympton of my utter geekishness that I imagined the blonde with the nice rack after I looked at my messy, cluttered equipment rack...

  • by marat (180984) on Tuesday June 15, 2004 @02:01PM (#9432323) Homepage
    Since power and probably complexity to program increases exponentially.
  • by James A. S. Joyce (784805) on Tuesday June 15, 2004 @02:03PM (#9432347) Homepage
    It's more convenient than Web interface and has no arbitrary limits...it's a quantum computing module for Perl [cpan.org]! There's also libquantum [www.enyo.de] for C users, and QCF for Matlabbers [charlesfox.org.uk].
    • It's more convenient than Web interface and has no arbitrary limits...it's a quantum computing module for Perl! There's also libquantum for C users, and QCF for Matlabbers.

      I don't know about QCF, but Quantum::Entanglement and libquantum take a different approach. The perl module gives a rather abstract layer without simulating the physics of a quantum computer at all. libquantum has been designed as a gate-level simulator which allows the analysis and optimization of complex quantum circuits.

      Here, the si
    • I am working on a quantum computing simulation in Java as well, and it's been up for a few months now. So far I only have single-qubit operations, which are useful only in explaining how qubits act and how they differ from classical bits. The meat of quantum computation doesn't really kick in until you can have multiple qubits entangled.

      Anyone interested can try it out here [jhu.edu]. You can take any valid input qubit, operate on it with any of six different single-qubit operators, and then see the output qub

  • Finally... (Score:5, Funny)

    by bairy (755347) * on Tuesday June 15, 2004 @02:04PM (#9432350) Homepage
    A "PC" that just scrapes Longhorn's requirements.
    • by mothz (788133)
      But how many frames per second will you get playing Duke Nukem Forever on it?
    • So is the new coolness factor "But... does it run longhorn?"
    • by NanoGator (522640)
      "A "PC" that just scrapes Longhorn's requirements."

      Giggle giggle, snort snort. We're so good at recycling other people's jokes, I wonder why none of us have girlfriends?
      • a sarcastic slashdot reader... you must be a killer with the ladies...
        • "a sarcastic slashdot reader... you must be a killer with the ladies..."

          There are plenty of ladies that think of me as being like a brother to them. Now all I need is a promotion and I'll finally hit second base!
          • Now all I need is a promotion and I'll finally hit second base!
            Is that the one where she gives you the root password to her home computer?
            • by Anonymous Coward
              Is that the one where she gives you the root password to her home computer?

              No, that's where you finger her box, grep a couple times, and then you stream into a secure tunnel. And if you're feeling particularly nasty, you can look for a trojan and go through the back door.
  • Tron (Score:2, Funny)

    by Sinful_Shirts (784047)
    "Now imagine the computing power of a few hundred qubits, if ever constructed..."

    Tron? :)
    • "Now imagine a few hundred qubits, if ever constructed..."
    • Re:Tron (Score:5, Funny)

      by DataPath (1111) on Tuesday June 15, 2004 @03:00PM (#9433080)
      Noah constructed a supercomputer called "The Ark" that was composed of 300 qubits by 50 qubits by 30 qubits, or 450,000 cubic qubits.

      Hmmm... sounds like the basis for some cheesy sci-fi - kind of like a matrix, but to protect minds from some psycho-viral plague.
    • Re:Tron (Score:2, Funny)

      by MZGuy (538887)
      "Skynet begins to learn, at a geometric rate. It becomes self-aware at 2:14 a.m. eastern time, August 29. In a panic, they try to pull the plug.."
  • by Nom du Keyboard (633989) on Tuesday June 15, 2004 @02:05PM (#9432369)
    Well, there goes my private encryption key.

    The only question left is, can a Quantum Computer Simulator handle the /. effect?

  • by Timesprout (579035) on Tuesday June 15, 2004 @02:05PM (#9432373)
    ie me, can somebody please explain in lay persons terms what simulation of quantum processes involves?
    • strictnein writes:
      the answer I got was.... I don't know. I don't even know what the fuck I did. Just pushed buttons and two minutes later it told me I was done! THE QUANTUM POWER IS AMAZING!

      Profane MuthaFucka writes:
      Isn't Qbit that dude that jumps all over the pile of blocks?

      maxbang writes:
      You changed the outcome of the loading time of the page by posting a link to it!

      If anyone can explain quantum computing to you and me, pal, it's patently obvious they don't read /.
    • by Anonymous Coward
      Traditional digital computing uses the basic bit that can be on/off. Quantum computing uses a qbit that can be 0, 1, or superposition of the two. Using this formalism, one can construct simulations that are "instantious" of complex systems that are modeled using probability distributions instead of traditional statistical techniques. The problem is that now the computational work has been shifted to setting up the model for the simulation. But the model will always be "instantious" (if this was quantum
    • by scrod98 (609124) on Tuesday June 15, 2004 @02:19PM (#9432554)
      I thought I might be helpful by looking it up [wikipedia.org].

      Now my head hurts and I still don't understand it, or any practical applications.

      Please someone start an amusing rant about how [insert OS here] would do this much better. Need entertainment to make head stop hurting. Or beer.

    • ie me, can somebody please explain in lay persons terms what simulation of quantum processes involves?

      From the paper, the quantum computer is based on having a number of atoms isolated from the rest of the system, with each atom being able to encode 0, 1 or unknown. Somehow, they've got to convert a desired algorithm into a combination of laser pulses to set the initial state, set the interdependencies between the Q-bits (or atoms), wait for the system to find the solution and read back the final result.
    • by NonSequor (230139) on Tuesday June 15, 2004 @02:41PM (#9432829) Journal
      Basically this stuff can't be done in polynomial time. For all quantum algorithms you start by setting a bunch of qubits into a uniform superposition of states (e.g. if you do this to 8 qubits and then measure them, you will be equally likely to get any number between 0 and 255 as your result). Then you can use these qubits as input into a function and effectively calculate the value of that function over every possible value of the input. The trouble is that you don't get 2^n different values of the function, you get a superposition of 2^n states. When you measure the output, you'll only find out one of the values of the function. So in order to get a working quantum algorithm, you have to manipulate the quantum state until you have a high probability of measuring the state you want.

      Quantum computing has other complexities. Every function must output as many qubits as it has for input. It's also impossible to make a copy of a qubit without altering the original qubit. This means that in any quantum programming langauge, all funciton parameters must be passed by reference. All functions must be invertible. This can be generally accomplished by leaving the inputs unaltered and writing the output to some scratch qubits which are set to 0 beforehand.

      If you want to learn more about quantum algorithms, I suggest you read up on Grover's search algorithm. It's much simpler than many quantum algorithms and it's also proven very adaptible to other situations.
    • In a traditional computer, a 32-bit memory location can store a 32-bit number. In a quantum computer, a 32-qubit memory location "stores" a value for each possible 32-bit number. For example, the value stored for 0 might be 0.01, the value for 1 might be 0.25, and so on. When you actually read the memory location, there is (in this example) a 1% chance that you will read a 0, and a 25% chance you will read a 1, and so on.

      The above is a little bit simplified. The probability isn't stored directly. Rat
    • "Let's see, I used to know what a qubit was. Well, don't you worry about that. Just get some particles, build it."

      The Wikipedia articles linked to below will certainly get you started, but they will make your head hurt.

      To ease the pain in your head I recommend Nick Herbert's Quantum Reality, a popular title, but clear, concise and accurate.

      There are a lot of popular works on Quantum Mechanics, but they all play the "pick any two" game with clarity, concision and accuracy. Herbert's is the only one I've f
    • by Isbiten (597220) <isbitenNO@SPAMgmail.com> on Tuesday June 15, 2004 @03:22PM (#9433370) Homepage
      http://www.howstuffworks.com/news-item210.htm

      The superior power of quantum computers is due to their ability to simultaneously exist in several different, wavelike states, called superpositions. Conventional bits of data only exist in one of two states, a 1 or 0. A qubit can exist in a superpostion that is simultaneously both 1 and 0. To handle quantum data, a computer's switches must be able to interact with one another while maintaining these superpositions, so that the qubits don't fall back into 1's or 0's. Until now, researchers have tried to hold qubits in entangled states, meaning the state of any one qubit depends on the state of all others. Using this method, the collapse of one qubit back into a 1 or 0 would result in lost data.
  • no fair! (Score:5, Funny)

    by maxbang (598632) on Tuesday June 15, 2004 @02:05PM (#9432380) Journal

    You changed the outcome of the loading time of the page by posting a link to it!

  • by Anonymous Coward on Tuesday June 15, 2004 @02:06PM (#9432393)
    'Now imagine the computing power of a few hundred qubits, if ever constructed...'

    A few hundred qubits would be very powerful at factoring numbers and other such specialized algorithms. But as far as linux and other "normal" software goes, a few hundred qubit computer won't be any better than a few hundred bit software.
  • by Nom du Keyboard (633989) on Tuesday June 15, 2004 @02:07PM (#9432407)
    32 node Athlon 3200 Myrinet Linux Cluster with 56GByte RAM!

    If that had been a 32 node Itantium cluster, Intel could have boasted of doubled Itantium sales for that quarter.

  • and the answer I got was....

    I don't know. I don't even know what the fuck I did. Just pushed buttons and two minutes later it told me I was done! THE QUANTUM POWER IS AMAZING!
  • Qbit? (Score:4, Funny)

    by Profane MuthaFucka (574406) <busheatskok@gmail.com> on Tuesday June 15, 2004 @02:08PM (#9432414) Homepage Journal
    Isn't Qbit that dude that jumps all over the pile of blocks?
  • On the Horizon (Score:3, Interesting)

    by WarriorPoet42 (762455) <nick@gibson-tech . c om> on Tuesday June 15, 2004 @02:09PM (#9432425) Journal
    The techs that can come for this computing power is unimaginable. Several physicits have said that it would take a quantum computer on the scall of a contemporary computer to achieve feats such as teleportation (Star Trek, eat your heart out!)
    Michael Chricton (of course) has dealt with the subject quite entertainingly in the novel Timeline. Again, I say the novel.
    • by hoggoth (414195) on Tuesday June 15, 2004 @02:20PM (#9432562) Journal
      > physicits have said that it would take a quantum computer on the scall of a contemporary computer to achieve feats such as teleportation

      Yeah, and all physicits know that if only we had enough computing power, magic would become true.

    • Just b/c we might have the computing power to store the states of every particle in the human body, doesn't mean we know how to do it. There's also the whole how to rebuild us from that data thing b/c of laws of physics. It's also possible that superluminal teleportation (faster than light) is impossible. Been reading some interesting stuff by a prof of mine at Princeton about his theory that three information theory axioms imply quantum mechanics (and thus, that no useful info can be transferred faster
    • Re:On the Horizon (Score:5, Interesting)

      by Jerf (17166) on Tuesday June 15, 2004 @02:49PM (#9432934) Journal
      Several physicits have said that it would take a quantum computer on the scall of a contemporary computer to achieve feats such as teleportation (Star Trek, eat your heart out!)

      References please? The fundamental problem with teleportation is the impossibility of simultaneouly (or even a reasonable appoximation thereof) introducing kilograms of matter to kilograms of other specially entangled matter, and sending the still-necessary "decoding" data stream to the reciever.

      By my count that's at least three impossible things. In order from least impossible to most:
      1. Sending the data stream anywhere in any reasonable amount of time. (It's that last clause that's a real killer, but this might be possible to some degree.)
      2. Introducing the teleportee to the entangled matter... imagine trying to touch every atom in your body simultaneously. You can't just smoosh the teleportee into the matter, it won't work. Oh, and no fair killing the teleportee to do it.
      3. Creating kilograms of entangled matter in the first place, and managing to keep it from reacting to its environment so it stays entangled... for entire seconds, days, weeks, years. Uh-uh, nope, not in this universe.
      I don't see how QC helps with any of these.

      (It's funny how something like this brings out all the physics fanboys who, in their ignorance of physics bounded only by Star Trek, honestly think we're making some sort of progress towards teleportation and the other impossibilities. Instead, real physics just keeps stacking up the reasons why these things are impossible, and the possibilities are receding, not advancing. Why do I have the sneaking suspicion WarriorPoet42's "several physicists" are just "some other teenager I found on a web board somewhere who likes to dazzle other fanboys with his command of physics^W Star Trek buzz-words"?)
  • Patent Fun (Score:4, Insightful)

    by RareEYE (104766) on Tuesday June 15, 2004 @02:09PM (#9432426)
    Aren't these the same folks that hold the MP3 encoder patents? If they are the same people I wonder when they'll patent the quantum computing algorithms?
  • harnessing the power of quantum computing to defend their webserver against hords of curious Slashdot geeks.
    • You may be joking, but database applications (and, by extension, file servers, since a fs is a kind of database) could, in theory, really benefit from this.

      Imaging a server where all the data is stored on qbits, and you just read the file you need off it. The throughput would be incredible. Or mabey use this to perform an SQL query on terabytes of data in an instant (more probable I think).

      Of course IANAP and this wouldn't solve bandwith problems, but hay, I can dream.
      • That would be difficult. The best search using a quantum algorithms right now is Grover wich provides only O(sqrt(n)) speedup over the list of unsorted n items. That is a theoretical limit (as of now!), so O(1) searches are not possible.
        I took a couple of quantum computing courses at my university as comp. sci electives, thinking we'll learn about the magical, ultra fast algorithms. Now I am fairly pessimistic about the future of quantum computing. So far (appart from quantum cryptography) they've only go
  • ...simulated? (Score:5, Interesting)

    by Cyclotron_Boy (708254) on Tuesday June 15, 2004 @02:10PM (#9432445) Homepage
    The scaling is not 1:1, so while it takes 32 Athlon processors with 56GB of ram, the processing power of 31 qbits is not that of the 32-processor cluster. This is an emulator, so the actual 31-qbit probably isn't quite as powerful as the hardware required to accurately mathematically model it. So while the computing power of a few hundred real qbits might be impressive, the computing power required to simulate those few hundred qbits would be extremely impressive.
    -F
    • ...while the computing power of a few hundred real qbits might be impressive, the computing power required to simulate those few hundred qbits would be extremely impressive.

      Well, if you count quantum computing as computing, you can easily simulate a few hundred qbits by the identity map onto the quantum computer itself ;)
    • Re:...simulated? (Score:3, Informative)

      by Big_Breaker (190457)
      In fact you'd need about 2^qbits of classical computers to directly simulate an equivalent quantum computer. That is because 2^qbit states exist for quantum computer on the road to calculating the answer. With only 32 computers involved in the simulation there must be a lot of serializing going on. Keeping track of the other states must be why they have so much RAM.

      I like to think of quantum computers as doing sorting rather than calculation. This is because you can give it the output to a classically
  • by JoeLinux (20366) <joelinux@gm a i l . c om> on Tuesday June 15, 2004 @02:11PM (#9432456) Homepage
    They've taken out all the fun of the "imagine a beowulf cluster of these..." by putting it in the article itself...DARN YOU SLASHDOT! DARN YOU TO HECK!
    • by Anonymous Coward
      Ah but in Heck we only handle the small stuff. Slashdot is big. I'm forwarding your request to Hell, where they can deal with it properly.

      Regards,
      Phil, Prince of Insufficient Light
  • by Nom du Keyboard (633989) on Tuesday June 15, 2004 @02:12PM (#9432467)
    And this quantum computer simulator contained the whole answer to Life, The Universe, and Everything...

    Until somebody went and looked at it.

    (Or does that need 42 Q-bits?)

    • And this quantum computer simulator contained the whole answer to Life, The Universe, and Everything...

      Until somebody went and looked at it.


      You're modded "Funny" but I actually found the post interesting. And here's why:

      There's a bit on THHGTTG that goes

      There is a theory which states that if ever anyone discovers exactly what the universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that

    • by Elder Entropist (788485) on Tuesday June 15, 2004 @03:58PM (#9433899)
      Something else that blew my mind with Douglas Adams' work and quantum:

      In one of the books (Life the Universe, and Everything?) he explains about how the infinite improbability generator works, and he states that an artifical brain (Bambleweeney Vector Plotter?) is connected to a really hot cup of tea.

      One of the problems with quantum computers is decoherence - isolating the qubits from the environment. I was reading an article where they were discussing a strategy for this by isolating the qubits in a fluid that had a strong random component to it, but where the many interactions averaged out to zero. A fluid with lots of brownian motion - in other words, a hot cup of tea would do.
  • by eviljolly (411836) on Tuesday June 15, 2004 @02:16PM (#9432511) Journal
    Imagine a beowulf cluster of....oh nevermind I don't feel like getting redundancy points.
  • by beef3k (551086) on Tuesday June 15, 2004 @02:17PM (#9432523)
    ... is develop a quantum algorithm that can handle a decent amount of slashdoters!
  • by menscher (597856) <menscher+slashdot.uiuc@edu> on Tuesday June 15, 2004 @02:26PM (#9432624) Homepage Journal
    I know everyone's excited about this, but keep in mind that it's 2^31 times slower than the thing it's trying to simulate. That's because it can't really take advantage of the exponential speedup from working with entangled states. Or, more accurately, it gets an exponential speedup at the cost of an exponential slowdown.
  • Interesting that an institute like this uses Zope / Plone for their web server.
  • by Anonymous Coward
    I've googled for it, and found articles and discussions on quantum computing no end, and seen the talk in computer magazines, but unfortunately none of the stuff has managed to even begin to explain to me how it really works. I just don't get the hang of it. (Maybe I'm just uncommonly thick... But I distinctly got the feeling that some of those editors weren't any better off...)

    I would really appreciate it if somebody could just briefly unfold it here, in fairly layman terms. What kind of problems do you s
  • by muskr (105370) on Tuesday June 15, 2004 @02:35PM (#9432734) Homepage Journal
    For those of you who don't know: The biggest problem with quantum computing is that you can never extract all the information you compute. So you can process y=f(x) for 2^31 values of x simultaneously, but when you go to read y from the computer, you just get one solution, and what's worse, you don't even know which value of X it corresponds to!

    Using Shor's factoring algorythm, however, you can extract one of the factors of a large number without knowing all the other factors. That would be useful for public key encryption. I wouldn't worry about your PGP key just yet though. 7 q-bit computers [ibm.com] are incredibly difficult to make. The process used to make the 7-bit QC does not scale to larger numbers easily. 2048 bit computers are way beyond our technical skills.

    On a side-note, I wonder if each computer simulates a q-bit (with one responsible for management). It would be the most obvious way to run the simulation, but may or may not be the fastest. There would need to be a lot of cross-communication since all the q-bits are entangled in any interesting quantum computation.
    • 7 q-bit computers are incredibly difficult to make. The process used to make the 7-bit QC does not scale to larger numbers easily.

      What about simulating these higher qbit computers? After all, these people can simulate 31 qbits, but there's no way we could build an actual quantum computer that big. Maybe we can build a simulator for 1024 or 2048 qbits and run Shors algorithm on that. However, if this is possible, then I'm sure the NSA has one and all your private keys are belong to them.
    • when you go to read y from the computer, you just get one solution, and what's worse, you don't even know which value of X it corresponds to!

      Not quite correct. Yes, you only get one. But you do know which value of x it corresponds to. You just can't pick your x value. It's part of the result, just like y is.

  • No, really... First time in the history of mankind... ;-)

    Paul B.
  • by sxtxixtxcxh (757736) on Tuesday June 15, 2004 @02:41PM (#9432815) Homepage Journal
    ... welcome our new simulated q-bit overlords.
  • What I dont really get about this, is that if a quantum computer can be simulated using normal computers, then whats the big deal about quantum computers in the first place? Of course there are all the textbook theories about the benefits of a quantum computer etc. But my limited understanding of quantum physics suggests to me that

    a) its impossible to simulate a quantum computer this way.
    and
    b), if it is possible then it cant possibly behave in the same way as a real one.

    nick
    (waiting for a physicist to en
  • by HarveyBirdman (627248) on Tuesday June 15, 2004 @02:50PM (#9432941) Journal
    It computes really fast as long as you don't actually want the answer.
  • by mveloso (325617) on Tuesday June 15, 2004 @03:10PM (#9433201)
    One unintended side effect of the QC has been that answers started to show up before questions were put in. Researchers are investigating, but suspect they already know the answer...
  • Quantum Fantasy (Score:3, Informative)

    by Colonel Panic (15235) on Tuesday June 15, 2004 @03:19PM (#9433320)
    Having just finished a class in Quantum computing I have these observations:

    1) Right now most of these quantum 'circuits' are implemented on NMR machines. They can realize a handfull of qubits. Not very cost effective. Unless you want your computer to double as an MRI machine (hey, you could rent it out every night!) it's not going to cost effective any time soon.

    2) Quantum Cellular Automata (QCA) - not strictly quantum computing, but a very interesting and potentially realizable (as in they might actually be able to fabricate these in the next 10 years or so) computing paradigm. The big advantages over current logic families (like CMOS): there is no current flow hence the power dissipation could be miniscule. They switch at Terahertz rates. QCA circuits are very small ( a majority gate in less space than a current CMOS transistor).

    3) Put the word 'Quantum' in front of something and it suddenly has a certain cachet.

    For the time being, most of this stuff is fantasy. At most we can build actual quantum circuits (not simulated) which have maybe 10 gates or so which isn't too useful and the implementation technology is extremely expensive (not to mention large and power hungry). QCAs may actually lead to something real - but they're not really quantum gates.
  • I hereby recommend when Quantum clusters come out we call them :

    Grendel Clusters!

    Obscure joke I know but hey, I'm a geek....

  • Unfortunately, I changed the outcome by measuring it, and am left with a -1 Insightful rant about 'Lawn Dart Deaths: Fact or Fiction?'

    Damn you Quantum Computing! Your seemingly random results have cost me everything!

Scientists will study your brain to learn more about your distant cousin, Man.

Working...