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Why now is the best time to study quantum computing (2014)
- mrdrozdov 10y agoHow does this compare to Justin Trudeau's explanation? https://m.youtube.com/watch?v=rRmv4uD2RQ4 https://m.youtube.com/watch?v=rRmv4uD2RQ4
- supergirl 10y agohmm, they both talk about quantum computing? the guy in the video says one phrase about it. the article says a bit more. strange question.
- dyarosla 10y agoThe 'guy in the video' is the prime minister of Canada- the question had value as it asked about someone's understanding of quantum who is in a position of political power.
- mrdrozdov 10y agoWhat's more interesting in the video is quantum computing being explained to a general audience. For young people looking for direction, both the video and the paper serve as persuasive pieces.
- mrdrozdov 10y agoThis video comes up frequently in social circles as for many people it was their first time having quantum computing explained to them (albeit simplistically). This paper seems to similarly explain briefly what quantum computing is and why it can be useful.
- daveguy 10y agoI wish that video continued so we could see whether or not he remembered and addressed the real question. That would have been impressive.
- gus_massa 10y agoThe sentence of Justin Trudeau is not an explanation. It looks like a something that someone with a very sallow knowledge about the subject would say. It has a few conceptual errors, and if you use it in a midterm the TA will mark it as a fail, and probably try to ban you from the university The important detail is the back story of that answer, that is unluckily unknown: * If it's genuine and he studied alone a few Wikipedia pages and similar stuff, then it's a good enough answer, he got the general idea, but he still don't understand the details. He must try to understand something about the qbits that still have only two states, and that they can combine exponentially. Keep trying, good luck. * If it was a PR setup, and a collaborator wrote it, then it's a bit sloppy. It's like going to a milk factory and saying that their business is related to squeezing cows. Next time try contact a physics. (But remember to redact the 2 pages about complex Hilbert spaces, it's difficult to give an short, ineligible and correct explanation.)
- typon 10y agoIt is honestly at par with explanations given in popular media by 'science' communicators like Neil deGrasse Tyson or Bill Nye.
- wfo 10y agoIf you ever gave an answer that would pass in a midterm examination in public as a politician, it would be complete disaster and nobody would understand what you are talking about and you would embarrass yourself. One of the most difficult challenges in science is to find the exact level of complexity in an explanation to fit your audience. You can see this if you go to a talk at a university -- often researchers are so obsessed with looking smart that they begin with extremely difficult material that 10% of their audience understands and go on from there, losing another percent every 10 minutes. Sometimes people will give a 'general audience' talk that is so simplified that everyone understands it but nobody gets anything out of it; it's just vague platitudes and intuitions. Most of Trudeau's language is so vague it could neither be called correct or incorrect (with a few exceptions). I think the purpose of it was: 1) to acknowledge to the researchers there that he took the time to learn /something/ about their highly technical field and that he finds it interesting and exciting. Contrast this with, for example, any politician that has ever existed in the history of the world. 2) to give a vague general explanation of what the phenomenon is that would make sense to his general audience, who don't even understand what computers are. Most importantly NOT: 3) To prove to scientists he understands science as well as they do. I think his speech was excellent in light of those two goals.
- ikeboy 10y agohttp://www.scottaaronson.com/blog/?p=2694 http://www.scottaaronson.com/blog/?p=2694
- mrdrozdov 10y agoThanks for the useful link!
- grifter2000 10y agohttp://syruptrap.ca/2016/04/delirious-exhausted-justin-trudeau-still-explaining-quantum-computing-to-journalists/ http://syruptrap.ca/2016/04/delirious-exhausted-justin-trude...
- carterschonwald 10y agoAnother really fascinating connection is with linear / resource logic and quantum computation. A lot of really neat resource logic connectives have interpretations as setting up quantum experiments.
- ThePhysicist 10y agoI gave an introductory talk about experimental quantum computing at the 31C3 where I explain how a basic two-qubit quantum processor works and how we can run a very simple quantum algorithm (Grover search) on it, here's the video link: https://youtu.be/1PcseLsYZ9Y https://youtu.be/1PcseLsYZ9Y
- messel 10y agoCool, thanks for sharing it here
- rburhum 10y agoThat was the best and easiest-to-follow overview I have seen of a quantum computing architecture. You clearly have a talent to explain complex concepts in a way that anybody with a CS undergrad background could understand. Thank you! Do you any other videos on this topic you would recommend watching?
- ThePhysicist 10y agoThanks for that great feeedback, I really appreciate it! I don't know any other videos, but I really like Nielsen/Chuang's book on Quantum Information. The first chapter is available for free: http://www.michaelnielsen.org/qcqi/QINFO-book-nielsen-and-chuang-toc-and-chapter1-nov00.pdf http://www.michaelnielsen.org/qcqi/QINFO-book-nielsen-and-ch... Michael Nielsen has a great blog btw where he talks not only about quantum computing but about machine learning and other interesting subjects as well.
- michael_nielsen 10y agoGlad you like the book and blog. I did a short video series on quantum computing: http://michaelnielsen.org/blog/quantum-computing-for-the-determined/ http://michaelnielsen.org/blog/quantum-computing-for-the-det... Never completed, but some people tell me they find it useful.
- ThePhysicist 10y ago
- d0m 10y agoIf I was still a student, I would definitely go in quantum computing. So much opportunities for innovation on a very cool subject. I often wonder what will happen at the 0-day quantum machine where it's not just a few qbit but the real deal.. I think anyone in possession of such technology will be able to crack any SSL certificate, and thus gain access to almost anything online. I wonder if criminal organisations aren't secretly investing in such thing? And, not to be paranoid, but we're almost certain it will be possible to build them, wouldn't it be prudent to start investing in the defense against such things? What kind of security could we have to counter a quantum computing? Would it only be possible to use quantum computing to defend against quantum computing?
- munin 10y agohttps://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography
- dcosson 10y ago> Would it only be possible to use quantum computing to defend against quantum computing? Not at all. As it is believed currently, there are a few problems (BQP space) such as the discreet logarithm that quantum computers can solve quickly. But lots of other hard problems, probably including all NP problems, cannot be solved exponentially faster by a quantum computer. See also http://security.stackexchange.com/questions/48022/what-kinds-of-encryption-are-not-breakable-via-quantum-computers http://security.stackexchange.com/questions/48022/what-kinds...
- onion2k 10y agoIf we know now is the best time to study quantum computing then we can't know where the best place to study it is.
- yomritoyj 10y agoIf we know now is the best time to study quantum computing then we can't know how much energy it will take to study it.
- curiousgal 10y agoWhatever you two are talking about is not a particle so whatever.
- futuravenir 10y agoSimultaneously a buzzkill and realistic.
- Falling3 10y agoIsn't there generally an overlap?
- criddell 10y ago> If we know now is the best time to study quantum computing But we don't know that at all. I would guess fifty years from now will be an even better time to study quantum computing.
- yesbabyyes 10y agoSo, your place then?
- dheera 10y agoAlthough I have studied the basics of quantum computing, I don't think it will become necessary for computer scientists to know the gory physics details of quantum computers. All they will need to know is that a certain function that is normally O(n^2) now has a magical implementation that is O(n), and another function that is normally exponential is now polynomial. Quantum computers will likely manifest themselves as co-processors, and you'll have a nice well-abstracted API to access those implementations within traditional languages, i.e. #!/usr/bin/env python4 from quantum import qc qc.init(device="/dev/quantum0") factors = qc.factor(15)
- colanderman 10y agoI came to the same conclusion after implementing a QC emulator. But note that QC doesn't even typically change exponential functions to polynomial; rather it will cut the exponent in half.
- reikonomusha 10y agoMore often than not it cuts the polynomial exponent in half via some use of Grover's.
- bogomipz 10y agoI'm having trouble wrapping my head around a quantum computer emulator, how is that implemented on a conventional computer? Could you elaborate? Thanks.
- dheera 10y agoYou can simulate quantum processes on a classical computer by keeping track of the amplitude of every basis state in the tensor product space of the thing you are simulating. Basically, you're running a physics simulation. It's extremely inefficient, and in terms of classical RAM required it is exponential in the number of qubits you are trying to simulate, but useful for prototyping, debugging, and learning about quantum algorithms. Google wrote a nice one that makes use of WebGL: http://www.quantumplayground.net/ http://www.quantumplayground.net/
- Rexxar 10y agoIs there any theoretical proof that quantum computing is inherently more efficient than current technology ? We can theoretically make a lot of simultaneous computations but are we sure we will not need exponentially more energy or time to get the result of computation when we add more qubits in future quantum computers ?
- irljf 10y agoYes. Grover's algorithm searches a disordered database in time sublinear in the number of elements, and provides a quadratic speedup over any possible classical algorithm. There are similar results for finding collisions etc. There is no proof, however, that quantum computers offer an exponential advantage on decision problems without some additional assumption, although this is widely believed to be the case, due in part to the exponential improvement of Shor's factoring algorithm compared to the best -known- classical algorithms.
- davorb 10y ago> are we sure we will not need exponentially more energy or time to get the result of computation The minimum free energy that must be expended to operate a computer is theoretically very close to zero, since it is not strictly necessary to use irreversible primitives[0], such as NAND gates, which is something that we do in traditional computers. For irreversible elements the theoretical requirement is about kT*ln(2) at temperature T. DNA uses about 100 kT per bit copied. I really recommend that you take a look at Feynman's introduction to quantum computing[1]. [0] http://www.cs.princeton.edu/courses/archive/fall04/cos576/papers/bennett73.html http://www.cs.princeton.edu/courses/archive/fall04/cos576/pa... [1] http://www.cs.princeton.edu/courses/archive/fall05/frs119/papers/feynman85_optics_letters.pdf http://www.cs.princeton.edu/courses/archive/fall05/frs119/pa...
- Rexxar 10y agoThanks for the links !
- ufo 10y agoQuantum computing is not about making simultaneous or parallel computations. Its about taking advantage of quantum mechanics (constructive and destructive interference of quantum waves, etc) to obtain very efficient algorithms for some kinds of problems.
- Qaw 10y agoAre there slim definition-theorem-proof-exercise-repeat style papers meant to be an introduction into the field? Maybe something in the style of http://www.jiblm.org/downloads/jiblmjournal/V090212I/V090212I.pdf http://www.jiblm.org/downloads/jiblmjournal/V090212I/V090212...
- dbranes 10y agoNielsen and Chuang certainly isn't slim, but chances are you won't need to read every chapter. The style is certainly what you're asking for though.
- coldcode 10y agoI took several classes in Quantum Mechanics around 1980. I am sure it would be far more interesting today. At least we have a more practical understanding of what it can do. I do wonder if we have any understanding of how it will change society?
- powercf 10y agoHas a quantum computer been built that can solve a problem faster or cheaper than conventional hardware? Afaict no. From an outsiders pov quantum computing seems to be advancing, but until the science and engineering can overcome the challenges and build something that can do something useful, then it seems too early to study it (outside of curiosity, the theory is kind of interesting).
- bchjam 10y agoHeisenbugs, what will become of you? in all seriousness though, I heard someone talk about their qc research a year or so ago and it was fascinating but I imagine debugging such systems could be quite the challenge
- ivan_ah 10y agoLearning quantum mechanics is not a big deal if you have a good background in linear algebra. I wrote a book on linear algebra that covers the basics of quantum mechanics as an application. No bullshit guide to linear algebra https://gum.co/noBSLA https://gum.co/noBSLA Here's an excerpt from Chapter 10 on QM: https://minireference.com/static/excerpts/noBSguide2LA_preview.pdf#page=107 https://minireference.com/static/excerpts/noBSguide2LA_previ... I also give a (non-hype) overview of the potential and obstacles associated with quantum computing.
- kjaer 10y agoArjen Lenstra was my professor for a year. When he we was asked about quantum computers he replied something to the effect of: "Back in the 90s, I asked leading quantum computing researchers when quantum computers would become available, and I was told 'in 10 years' time'. I asked them again 10 years later, in the 2000s, and was met with the same reply. And I've asked again just recently, and I was told, once again: 'in 10 years'. Now, I'm a computer scientist, so I my prediction of the future can only be that what has repeated itself will continue to do so. According to this logic, quantum computers will never be available." (I'm quoting very loosely, because this was just an off-topic remark during a lecture I attended a year ago, so I don't remember the exact phrasing. But I do believe that this was the gist of it). I'm genuinely afraid that quantum computing will just remain a purely theoretical field, and that we won't see any practical applications to it. To me, that does not make it worth pursuing. I'd love to be wrong, though, because it sounds super interesting.
- ycmbntrthrwaway 10y ago> According to this logic, quantum computers will never be available. No, it just means that time until quantum computers are available is distributed exponentially.
- kjaer 10y agoI don't think I really understand what you mean. What he said was that it stays at 10 years indefinitely. Either way, x+10 and e^x both go to infinity, so I guess the conclusion is the same, right?
- tgb 10y agoI think the joke was to say that 'quantum computing being discovered' follows a Poisson distribution which models occurrences of events that arrive in a manner so that each one is independent of the previous one. Such as letters arriving in the mail or winning at roulette. Regardless of how long it's been since your last letter, you still guess that the next one will come on average, say, 5 days from now. Regardless of how long its been since you won at roulette, you should still expect your number to come up on average 38 tries from now. The exponential part is more like e^(-x) and refers to the exponential distribution [1] that gives the distribution of intervals in between Poisson events. So if its 'distributed exponentially' (whatever that means for a one-off event), the joke is that this would then give rise to the situation where researchers are always correct guessing 10 years off, even if they've been saying that for decades. [1] https://en.wikipedia.org/wiki/Exponential_distribution https://en.wikipedia.org/wiki/Exponential_distribution
- mathgenius 10y agoSome of my noticings.. Many of the "founders" of the field are still quite young, which is refreshing. Although they tend to say how back in the old days it was so much easier to get new stuff published. Maybe that is so, but my personal opinion (as an apprentice) is that we haven't reached the hockey stick yet.