5 ms·
New work extends the thermodynamic theory of computation
- dlojudice 2y agoEvery computing system, biological or synthetic, from cells to brains to laptops, has a cost. This isn’t the price, which is easy to discern, but an energy cost connected to the work required to run a program and the heat dissipated in the process. Researchers at SFI and elsewhere have spent decades developing a thermodynamic theory of computation, but previous work on the energy cost has focused on basic symbolic computations — like the erasure of a single bit — that aren’t readily transferable to less predictable, real-world computing scenarios.
- yodon 2y agoIf you're going to directly quote the first two paragraphs of the article, it's generally considered good form to indicate you're quoting from the article (for example by starting your text with ">")
- gryn 2y agoif you find this interesting you'll also find the publications of J.P Cruthfield interesting, he seem to have worked in this same institute up to 2004 before moving to UC Davis. he has 20+ years worth of papers on the topic, I keep procrastinating reading them esp the ones about what he calls epsilon machines. I don't really understand this topic, but find the premise interesting enough. here's a paper about the intrinsic cost of modularity https://journals.aps.org/prx/abstract/10.1103/PhysRevX.8.031036 https://journals.aps.org/prx/abstract/10.1103/PhysRevX.8.031... Anatomy of a Bit: https://arxiv.org/abs/1105.2988 https://arxiv.org/abs/1105.2988 Modes of Information Flow https://arxiv.org/abs/1808.06723 https://arxiv.org/abs/1808.06723 stuff related to Landauer's bound https://arxiv.org/abs/1812.11241 https://arxiv.org/abs/1812.11241 https://arxiv.org/abs/1909.06650 https://arxiv.org/abs/1909.06650 https://www.researchgate.net/publication/350794561_Refining_Landauer%27s_Stack_Balancing_Error_and_Dissipation_When_Erasing_Information https://www.researchgate.net/publication/350794561_Refining_...
- idontknowtech 2y agoFrom the headline, I thought this was yet another attempt by some silicon valley bro to handwave furiously about everything being thermodynamics. Thankfully, this was not the case. I'm kinda surprised nobody's done this before, given how important estimating wastage is.
- gs17 2y agoThe thermodynamic "limit" is pretty small compared to any other waste in a system (from Wikipedia): > At room temperature, the Landauer limit represents an energy of approximately 0.018 eV (2.9×10^−21 J). Modern computers use about a billion times as much energy per operation.
- porphyra 2y agoThe Landauer principle gives a lower bound for the energy needed for computation (specifically, irreversible information erasure). Is it possible that there is a heretofore undiscovered lower bound that is higher? As an aside, modern computers perform computation like a car with square wheels --- in discrete steps, where all your energy is irreversibly discarded in each step. Theoretically, reversible computing [1] can do useful work with less energy without needing to erase information. [1] https://en.wikipedia.org/wiki/Reversible_computing https://en.wikipedia.org/wiki/Reversible_computing
- colmmacc 2y agoOne of Feynman's lesser known works is his lectures on computation. https://www.amazon.com/Feynman-Lectures-Computation-Frontiers-Physics/dp/0738202967 https://www.amazon.com/Feynman-Lectures-Computation-Frontier... Feynman is not as expert on the topic as he is on his core research, but his gift for great explanation carries over and makes the material more accessible. The lectures are ground in thermodynamics and the related information theories, and there's a very accessible lecture in there too about Maxwell's Daemon. Most of the material is very foundational and still correct, so it's a good read for anyone who is interested in the area. I'm glad I read it before I had to deal with more complicated and statistical approaches to computation and entropy.
- gnatman 2y agoFenyman worked with Thinking Machines on their first supercomputer, The Connection Machine in the 80s. Here's some great background and anecdotes from the founder, Danny Hillis: https://longnow.org/essays/richard-feynman-connection-machine/ https://longnow.org/essays/richard-feynman-connection-machin...
- winwang 2y agoHe also proposed using quantum computers to solve "hard" physical systems. https://arxiv.org/pdf/2106.10522 https://arxiv.org/pdf/2106.10522 Though, I'm unsure if he were the first to do so in a semi-public manner.
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- anonzzzies 2y agoThis is important for our resources and connected to the (at least for me) very interesting field of reversible computing.
- rulalala 2y agoIs SFI alive after all his founders are long gone? I think so, but really it is increasingly difficult to discern its current unique contribution to the global scientific landscape.
- pmayrgundter 2y agoAdjacent work from Fields & Levin 2021 on the thermodynamics of cellular process, arguing that due to the information processing demands and classical thermo minimal power requirements per operation for loose estimates of protein control, aggregate cellular metabolism power requirements are off by 10-15 orders of magnitude of available. They then conclude that cellular processes are using quantum coherent processes for major work internally and externally (p17). https://chrisfieldsresearch.com/quantum-cells-pre.pdf https://chrisfieldsresearch.com/quantum-cells-pre.pdf
- delichon 2y agoSo perhaps like consciousness. https://www.youtube.com/watch?v=R6G1D2UQ3gg https://www.youtube.com/watch?v=R6G1D2UQ3gg
- darby_eight 2y agoI smell Penrose bullshit in the air Of course the brain uses quantum mechanics, it exists in the real world. What has yet to be demonstrated is any link to consciousness.
- delichon 2y agoThe link addresses your point.
- darby_eight 2y agoI am not watching a video
- bandrami 2y agoA video is always a red flag for me. If you can't make the argument in text that's a sign of something.
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- nico 2y agoWhat are irreversible problems? Any good/fun and maybe practical, examples?
- sponaugle 2y agoFrom a boolean logic point of view - AND is irreversible, since (1 .AND. 0) is 0, as is (0 .AND. 0.) Going from the result (0), you can't reverse and get the starting inputs. NOT however is reversible, since 1 .NOT. -> 0, and you can get back to 1 with another .NOT.
- nico 2y agoThank you for the examples It seems like AND is similar to calculating a binary derivative (https://news.ycombinator.com/item?id=40328821 https://news.ycombinator.com/item?id=40328821) In a certain way you could say you can integrate AND For example 1 AND 0 = 0 Now if I only have 0 as a result, it means one of the arguments was 0, and the other is either 0 or 1 So the “integral” of AND(0,x) = 0, is (0, (either 0 or 1)) or just x = (either 0 or 1) [0 or 1 meaning one means either. It doesn’t mean 0 OR 1, which would be 1] This is analog to the result of an integral being expressed as a function + C (constant). The C part is the uncertainty of the result, just like having (0 or 1) for AND The (0 or 1) part can also be expressed as a probability distribution, for example p(0)=0.5,p(1)=0.5 which then you can use to “sample” the integral of AND by randomly taking a (0 or 1) and using it as argument to AND(0, x)
- slwvx 2y agoThe underlying paper: https://journals.aps.org/prx/pdf/10.1103/PhysRevX.14.021026 https://journals.aps.org/prx/pdf/10.1103/PhysRevX.14.021026 I skimmed it; it's not super accessible.
- spacetimeuser5 2y ago>>Every computing system, biological or synthetic, from cells to brains to laptops, has a cost. Obviously so, fetching tiny potatoes from point A to point B by monkeys has a cost.
- hi-v-rocknroll 2y agoPerhaps a PhD EE here knows: Why didn't reversible computing go anywhere?
- AlotOfReading 2y agoIt's only meaningful for traditional computing if you can build circuits orders of magnitude more efficient than we can currently.