Ultimate physical limits to computation · HackerPapers discussions

Ultimate physical limits to computation — HN submission

Sun, 04 Oct 2026 06:35:07 GMT

Ultimate Physical Limits of Computation (2000)

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — HN submission

Thu, 03 Jul 2025 16:36:19 GMT

Physical Limits to Computation (2000)

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — HN submission

Fri, 20 Jan 2023 13:56:49 GMT

Physical Limits to Computation

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — HN submission

Sun, 27 Nov 2022 19:13:03 GMT

Ultimate physical limits to computation (2000) [pdf]

5 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — mentioned by adrianN

Sun, 09 Oct 2022 09:38:34 GMT

Maybe read https://arxiv.org/pdf/quant-ph/9908043.pdf before you think about computers operating on 2*140 objects and try to be less aggressive in your comments.

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Ultimate physical limits to computation — mentioned by reincarnate0x14

Wed, 23 Feb 2022 21:16:56 GMT

I'd be curious if anyone with understanding of memory transistor density has an idea of what sort of physical footprint and power requirements 128-bit addressable memory would look like, because I'm having a hard time picturing even a distributed, shared virtual memory space realistically exceeding 16 exabytes. It looks like the Fugaku ARM cluster with 158,000 nodes uses < 5 PiB for 40 MW. As an aside, man does reading something from @sgi.com on USENET take me back to a better time. Title should probably note [1995] [0] https://www.fujitsu.com/global/about/innovation/fugaku/speci... [1] Also…

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Ultimate physical limits to computation — mentioned by Isinlor

Mon, 07 Jun 2021 22:20:27 GMT

In the Perfect Imperfection by Jacek Dukaj [0] has something called "Remy's curve" [1]. On the curve you can find: - Ultimate Computer is the computer using the best hardware as allowed by the physical constants of our universe. See also physics of computation. - Inclusions are in essence 'pocket universes'. They are created for specific entities to run hardware in a dedicated universe with physical constants different from ours, allowing for better performance than those in our universe - Ultimate Inclusion is the inclusion with the best possible set of physical constants in the entire…

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Ultimate physical limits to computation — mentioned by adrianN

Tue, 12 Jan 2021 09:02:22 GMT

We have some upper bounds on what is physically possible: https://arxiv.org/abs/quant-ph/9908043

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Ultimate physical limits to computation — mentioned by messe

Thu, 25 Jun 2020 18:02:02 GMT

An interesting paper in somewhat the opposite direction, but still building on Landauer's work is "Ultimate physical limits to computation": https://arxiv.org/abs/quant-ph/9908043 The end of the abstract: > [...] quantitative bounds are put to the computational power of an `ultimate laptop' with a mass of one kilogram confined to a volume of one liter.

Paper and discussion history. A mention is not an endorsement.

Ultimate physical limits to computation — HN submission

Mon, 30 Sep 2019 05:00:09 GMT

Ultimate Physical Limits to Computation (2000)

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — mentioned by kragen

Mon, 29 Jul 2019 12:21:47 GMT

It seems likely that Moore’s Law will someday be resurrected, perhaps in a weaker form, but I wouldn't bet heavily on any particular invention being the one that resurrects it. I say it seems likely because Landauer's limit works out to about 0.003 attojoules per bit erasure at room temperature, while current top-efficiency processors use on the order of 100–200 picojoules per instruction — say, about 1 picojoule per bit erasure. So we're about 10 orders of magnitude from Landauer's limit, even before we switch to reversible computation, or drop Landauer's limit by a factor of 75 by operating…

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Ultimate physical limits to computation — HN submission

Sun, 25 Feb 2018 19:28:02 GMT

Ultimate physical limits to computation

5 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — HN submission

Tue, 13 Feb 2018 04:06:00 GMT

Ultimate physical limits to computation, Seth Lloyd (2000)

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — mentioned by dvt

Wed, 24 Jan 2018 23:44:47 GMT

A very famous and popular paper that's often cited when debating the simulation hypothesis. I'm squarely in the "not a simulation" camp for a few reasons. 1) Limits of computation. First, we need to find out whether or not the universe is computable. To me, it doesn't seem like it is[1] due to "funky" phenomena like quantum effects. 2) Consistency. It doesn't seem that a simulation ought to be as consistent as our universe appears to be. In fact, if there was a hyper-advanced society making simulations out there, the great majority of simulations would be failed attempts or bug-addled…

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Ultimate physical limits to computation — mentioned by tambourine_man

Tue, 16 Aug 2016 02:34:28 GMT

http://arxiv.org/pdf/quant-ph/9908043.pdf

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Ultimate physical limits to computation — mentioned by kanzure

Thu, 16 Jun 2016 18:16:39 GMT

see also: "Ultimate physical limits to computation" http://arxiv.org/pdf/quant-ph/9908043v3.pdf "Limits on fundamental limits to computation" http://arxiv.org/pdf/1408.3821v2 "The physics of information processing superobjects: daily life among the Jupiter brains" http://diyhpl.us/~bryan/papers2/The%20physics%20of%20informa...

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Ultimate physical limits to computation — mentioned by jere

Fri, 22 Apr 2016 15:30:53 GMT

I've always found the idea of the universe being a simulation rather silly. There are estimated to be 10^80 particles in the observable universe. Assuming our universe is being simulated on an earth sized computer (this is mind bogglingly ridiculous to me) and that the simulation meets Bremermann's limit (also ridiculous, since we're 40 orders of magnitude away according to this http://arxiv.org/pdf/quant-ph/9908043v3.pdf), then it would take on the order of a whole earth day to simulate a single time step. Of course, perhaps the host universe doesn't have the same limitations. Such…

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Ultimate physical limits to computation — mentioned by sevenless

Fri, 22 Apr 2016 14:49:06 GMT

This is an entertaining read: Ultimate Limits to Computation http://arxiv.org/abs/quant-ph/9908043

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Ultimate physical limits to computation — mentioned by scottlocklin

Sun, 28 Jun 2015 20:32:25 GMT

I liked Seth Lloyd's earlier paper better: http://arxiv.org/abs/quant-ph/9908043

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Ultimate physical limits to computation — mentioned by Sniffnoy

Sun, 31 May 2015 19:21:55 GMT

A note -- if you're linking to arXiv, it's better to link to the abstract (http://arxiv.org/abs/quant-ph/9908043, or http://arxiv.org/abs/quant-ph/9908043v3 for this particular version) rather than directly to the PDF. From the abstract, one can easily click through to the PDF; not so the reverse. And the abstract allows one to do things like see different versions of the paper, search for other things by the same authors, etc. Thank you!

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Ultimate physical limits to computation — HN submission

Sun, 31 May 2015 12:30:08 GMT

Physical Limits to Computation (2000) [pdf]

40 points; 21 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — HN submission

Tue, 09 Dec 2014 01:51:14 GMT

Ultimate physical limits to computation

1 point; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — mentioned by pbsd

Mon, 26 May 2014 07:23:23 GMT

There is another more fundamental limit, credited to Margolus and Levitin [1], which puts the maximum speed of a (quantum) gate at 2E / h operations per second for a system of energy E and Planck constant h. Given the energy of the sun quoted in the article, this puts the upper limit of bit flips per second at 2^193. Seth Lloyd's 'Ultimate physical limits to computation' [2] goes into further detail on this subject. However, the notion of zero energy dissipation (scalable quantum computers will likely need error correction, which implies bit erasure) on any real system is ludicrous, and I…

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Ultimate physical limits to computation — mentioned by achille

Thu, 20 Feb 2014 06:37:40 GMT

Read this in the past and there's a few things that bother me * It's impossible to simulate a universe of our current resolution, because it would take more matter than the original universe. * You can't just simulate 'observable areas'. Everything needs to be simulated. * An infinite loop does not end, even in an infinitely powerful computer * A fun calculation from the ZFS folks: To fully populate a 128bit filesystem (ie permute all combinations) you a lot of energy. So much energy you could boil the world's oceans, See: * [1] Physical Limits of Computation…

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Ultimate physical limits to computation — mentioned by tobiasu

Fri, 14 Jun 2013 17:55:43 GMT

http://arxiv.org/pdf/quant-ph/9908043.pdf

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Ultimate physical limits to computation — mentioned by anateus

Mon, 15 Oct 2012 05:39:54 GMT

Programming the Universe by Seth Lloyd (physics professor at MIT who likes to call himself a "quantum mechanic"). Here's a relevant paper by Lloyd titled "Ultimate physical limits to computation": http://arxiv.org/abs/quant-ph/9908043v3

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Ultimate physical limits to computation — mentioned by nullc

Sun, 11 Mar 2012 21:25:53 GMT

It uses energy to do so— just like a heat pump can heat your home with greater output than electrical input, but not no electrical input. The more exciting detail is that computation itself doesn't increase entropy, at least not if reversible computing is use. Only errors or, rather, their correction do... So things may be more rosy than you might guess: http://arxiv.org/abs/quant-ph/9908043

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Ultimate physical limits to computation — HN submission

Thu, 21 Jul 2011 13:01:25 GMT

Ultimate physical limits to computation

7 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — mentioned by sigil

Mon, 25 Apr 2011 04:13:31 GMT

> Suppose that there is a network that is never partitioned, and machines connected to that network that never fail. In that case consistency and availability should be perfect. You mean, in that case tolerance to partition and availability should be perfect. > Perhaps someday we may be able to say that the odds of enough partitions or machine failures to make the system unavailable are lower than the odds of you getting struck by lightning, at which point you will have for practical purposes defeated the constraints of the CAP theorem. So this is the really interesting question. All the CAP…

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Ultimate physical limits to computation — mentioned by adrianN

Sat, 26 Feb 2011 14:05:51 GMT

The Ultimate Physical Limits of Computation: http://arxiv.org/pdf/quant-ph/9908043

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Ultimate physical limits to computation — mentioned by gwern

Tue, 18 Jan 2011 15:06:31 GMT

Hm. It appears Blogspot ate my comments. So I guess I'll just paste it here. --- > The "for a time" bit is crucial. There is as Feynman said "plenty of room at the bottom" but it is by no means infinite given actually demonstrated physics. That means all growth curves that look exponential or more in the short run turn over and become S-curves or similar in the long run, unless we discover physics that we do not now know, as information and data processing under physics as we know it are limited by the number of particles we have access to, and that in turn can only increase in the long run…

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Ultimate physical limits to computation — mentioned by dschobel

Sat, 20 Nov 2010 14:09:35 GMT

Agreed. Unfortunately the Nature article is behind a paywall but the original paper is available on arxiv: http://arxiv.org/abs/quant-ph/9908043

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Ultimate physical limits to computation — HN submission

Sat, 19 Jun 2010 10:08:49 GMT

What's the power of an "ultimate laptop" (of 1kg mass in 1L volume)

2 points; 1 discussion reply on HN. Paper and source history. A submission is not an endorsement.

Ultimate physical limits to computation — HN submission

Wed, 25 Jun 2008 06:43:23 GMT

Nature: The Ultimate Physical Limits of Computation

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.