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Is the Universe its own Largest Computer?

Posted by ryuzaki0 on from the where-are-the-mice dept.

missingmatterboy writes: "If the universe is simply a giant calculating machine, how big is it? Seth Lloyd, who two years ago worked out the theoretical maximum possible power a laptop computer could posess, has now "estimated how much information the Universe can contain, and how many calculations it has performed since the Big Bang." His conclusion: you'd need about 10^90 bits, with something like 10^120 manipulations of those bits, to express the universe since time began."

3 of 610 comments (clear)

  1. Re:Change = Calculation? by 2nd+Post! · · Score: 5, Interesting

    As far as I can recall, one of the basic premises of entropy and information theory is that *everything* can be expressed in bits.

    If everything can be expressed in bits, then everything is computable.

    A stupid question is whether the universe is a determinstic Turing machine or not, or whether it is by very nature indeterministic :P

    It's not that something has to be made into a computer so much as redefining one's perspective of what a computer is to accomodate the realities of the universe; that DNA is a storage mechanism, with RNA and DNA replication and protein synthesis being complex computation processes. Or that the universe is really expressible as a bunch of states (read his article, and you'll see that), and as such the traversal from state to state is no more complex than following a state diagram in a really big state machine...

    Which is just a computer, doncha know?

    --

    GPL Deconstructed
  2. Moore or less... by jolshefsky · · Score: 5, Interesting
    According to Moore's law, the typical desktop computer should be able to simulate the universe in less than 600 years.

    (18 months per double; 10^120 =~= 2^399; 1.5 years * 399 = 598.5 years)

    --
    --- Jason Olshefsky

    Karma: Poser (mostly affected by adding this line long after everyone else did)

  3. It is, of course, even more complicated than that. by RyanFenton · · Score: 5, Interesting


    For instance, gravity seems to have a universal effect. It diminishes over distance, but ultimately never stops having an effect. Thus, for every movement, you'd first need to look at all elements of the "gravity map" to determine your precise gravity vector, then you'd need to update the "gravity map" with your movement. This would seem to have at least an N^2 effect. The universe doesn't seem at least to kludge on things like this.

    Many forces act like this, which would tend to make the exponent on the number of bit manipulations required blossom much faster than predicted. Take a look at raytracer graphic design to see how messy reality can be when you introduce more than a couple elements into a scene, much less of course a universe. If one is going for a true simulation of reality, at least force by force, particle by particle, I believe it's going to be more complex than this estimation.

    :^)

    Ryan Fenton