All of jallen's Comments + Replies

Did you read about Google's partnership with NASA and UCSD to build a quantum computer of 1000 qubits? Technologically exciting, but ... imagine a world without encryption. As if all locks and keys on all houses, cars, banks, nuclear vaults, whatever, disappeared, only incomparably more consequential. That would be catastrophic, for business, economies, governments, individuals, every form of commerce, military communication.... Didn't answer your question, I am sorry, but as a "fan" of quantum computing, and also a person with a long time interest in the quantum zeno effect, free will, and the implications for consciousness (as often discussed by Henry Stapp, among others), I am both excited, yet feel a certain trepidation. Like I do about nanotech. I am writing a long essay and preparing a video on the topic, but it is a long way from completion. I do think it (qc) will have a dramatic effect on artifactual consciousness platforms, and I am even more certain that it will accellerate superintelligence (which is not at all the same thing, as intelligence and consciousness, in my opinion, are not coextensive.)

I've worked on the D-Wave machine (in that I've run algorithms on it - I haven't actually contributed to the design of the hardware). About that machine, I have no idea if it's eventually going to be a huge deal faster than conventional hardware. It's an open question. But if it can, it would be huge, as a lot of ML algorithms can be directly mapped to D-wave hardware. It seems like a perfect fit for the sort of stuff machine learning researchers are doing at the moment. About other kinds of quantum hardware, their feasibility remains to be demonstrated. I think we can say with fair certainty that there will be nothing like a 512-qubit fully-entangled quantum computer (what you'd need to, say, crack the basic RSA algorithm) within the next 20 years at least. Personally I'd put my money on >50 years in the future. The problems just seem too hard; all progress has stalled; and every time someone comes up with a way to try to solve them, it just results in a host of new problems. For instance, topological quantum computers were hot a few years ago since people thought they would be immune to some types of incoherence. As it turned out, though, they just introduce sensitivity to new types of incoherence (thermal fluctuations). When you do the math, it turns out that you haven't actually gained much by using a topological framework, and further you can simulate a topological quantum computer on a normal one, so really a TQC should be considered as just another quantum error correction algorithm, of which we already know many. All indications seem to be that by 2064 we're likely to have a human-level AI. So I doubt that quantum computing will have any effect on AI development (or at least development of a seed AI). It could have a huge effect on the progression of AI though.

Based on the current understanding of quantum algorithms, I think the smart money is on a quadratic (or sub-quadratic) speedup from quantum computers on most tasks of interest for machine learning. That is, rather than taking N^2 time to solve a problem, it can be done in N time. This is true for unstructured search and now for an increasing range of problems that will quite possibly include the kind of local search that is the computational bottleneck in much modern machine learning. Much of the work of serious quantum algorithms people is spreading this quadratic speedup to more problems. In the very long run quantum computers will also be able to go slightly further than classical computers before they run into fundamental hardware limits (this is beyond the quadratic speedup). I think they should not be considered as fundamentally different than other speculative technologies that could allow much faster computing; their main significance is increasing our confidence that the future will have much cheaper computation. I think what you should expect to see is a long period of dominance by classical computers, followed eventually by a switching point where quantum computers pass their classical analogs. In principle you might see faster progress after this switching point (if you double the size of your quantum computer, you can do a brute force search that is 4 times as large, as opposed to twice as large with a classical computer), but more likely this would be dwarfed by other differences which can have much more than a factor of 2 effect on the rate of progress. This looks likely to happen long after growth has slowed for the current approaches to building cheaper classical computers. For domains that experience the full quadratic speedup, I think this would allow us to do brute force searches something like 10-20 orders of magnitude larger before hitting fundamental physical limits. Note that D-wave and its ilk are unlikely to be relevant to this story; w

I've seen several papers like "Quantum speedup for unsupervised learning" but I don't know enough about quantum algorithms to have an opinion on the question, really.

The D-Wave quantum computer solves a general class of optimization problems very quickly. It cannot speed up any arbitrary computing task, but the class of computing problems which include an optimization task it can speed up appears to be large. Many "AI Planning" tasks will be a lot faster with quantum computers. It would be interesting to learn what the impact of quantum computing will be on other specific AI domains like NLP and object recognition. We also have: -Reversible computing -Analog computing -Memristors -Optical computing -Superconductors -Self-assembling materials And lithography, or printing, just keeps getting faster on smaller and smaller objects and is going from 2d to 3d. When Bostrom starts to talk about it, I would like to hear people's opinions about untangling the importance of hardware vs. software in the future development of AI.