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arXiv:quant-ph/0110141quant-ph

Computational capacity of the universe

Seth Lloyd

Abstract

Merely by existing, all physical systems register information. And by evolving dynamically in time, they transform and process that information. The laws of physics determine the amount of information that a physical system can register (number of bits) and the number of elementary logic operations that a system can perform (number of ops). The universe is a physical system. This paper quantifies the amount of information that the universe can register and the number of elementary operations that it can have performed over its history. The universe can have performed no more than $10^{120}$ ops on $10^{90}$ bits.

arXiv comments
17 pages, TeX. submitted to Nature
Journal reference
Phys.Rev.Lett.88:237901,2002
DOI
doi:10.1103/PhysRevLett.88.237901
Subjects
quant-phQuantum Physics

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Linked by 6 identifiable commenters in 6 comments across 6 threads, from Aug 2007 to Oct 2023. Found in 5 HN submissions from Nov 2007 to Feb 2025. Open submission discussions.

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Discussed in comments6 threads

  1. Find the date of your birthday in the number pi 1 comment

    • [Arbitrary number] is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road, but that's just peanuts to [arbitrary number]. Assuming the binary digits of π are randomly distributed[0], any given n-bit…

      ben_wView on HNParent context

  2. BB(3, 3) is Hard 1 comment

    • BB(6) might be too large even to store (let alone compute) using all the mass and energy of the universe. I think the computable limit if you converted all the mass in the observable universe to energy (E = mc^2) would be BB(5), assuming adherence to the Laundauer Limit[0].…

      reapermanView on HNParent context

  3. The Universe Is Not a Simulation, but We Can Now Simulate It 1 comment

    • https://arxiv.org/pdf/quant-ph/0110141.pdf https://web.archive.org/web/20171111160807/http://fab.cba.mi... https://www.amazon.com/dp/B000GCFBP6/ref=dp-kindle-redirect?... Also read the references.

      stillbourneView on HNParent context

  4. How Many Decimals of Pi Do We Really Need? 1 comment

    • It's been estimated that if the universe were a computer, it could have performed no more than 10^120 operations on 10^90 bits of data so far (based on the size, age, and total energy of the known universe). http://arxiv.org/abs/quant-ph/0110141 I think the number of physically…

      mc808View on HNParent context

  5. A Turing Machine in the Classic Style 1 comment

    • Except that the computational capacity of the universe is finite (see http://arxiv.org/abs/quant-ph/0110141).

      neilcView on HNParent context

  6. Computational Capacity of the Universe [PDF] 1 comment

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