5 ms·

For those, who want to read it in lay man's language, they can go through following articles: https://www.technologyreview.com/s/429561/the-measurement-that-wo

• sakopov 10y ago
  Interesting. So we're a simulation that can simulate 15 (femto)meters of cosmos that is indistinguishable from reality. This isn't much but it's still absolutely mind-bending. Reminds me of the movie The 13th Floor [1] [1] http://www.imdb.com/title/tt0139809/ http://www.imdb.com/title/tt0139809/
  • codesnik 10y ago
    femtometers?
    • sakopov 10y ago
      Yep. Typoed.
• yodon 10y ago
  The tech review summary seems to be saying this super intelligent universe-simulating computer builder doesn't know about Bresenham's line drawing algorithm [0] and as a result it can only walk high energy particles along a limited number of paths. [0] https://en.m.wikipedia.org/wiki/Bresenham%27s_line_algorithm https://en.m.wikipedia.org/wiki/Bresenham%27s_line_algorithm
  • komali2 10y ago
    Possibly? I can see why one would want to assume that an entity that can simulate a universe would be able to know more than the collective ability of that simulation, but on the other hand, we simulate things and learn unexpected results from our simulations. I think it's entirely feasible that a simulation can generate more knowledge, or different knowledge, than exists outside the simulation.
    • yodon 10y ago
      Certainly, but the idea that some hyper intelligent entity would develop the tech to build a universe-scale finite element simulator without groking anti-aliasing along the way is simply absurd. Bresenham's algorithm is a big deal because it's essentially the first thing everyone needs to invent when they start trying to render continuous processes on a discrete grid.
      • to3m 10y ago
        Bresenham's algorithm draws aliased lines.
      • raattgift 10y ago
        Where would you introduce the trajectory-correcting algorithm? In General Relativity, fundamental particles are simply taking shortest paths through spacetime, and where there are multiple short paths, the one that extremizes the timelike distance is favoured. In a perturbative theory of gravitation, you introduce corrections on the particles by way of graviton interactions. Worse, whether a local patch of energy-density amounts to a particle is observer-dependent; in both approaches above an accelerated observer sees more particles than an unaccelerated one does. That includes more gravitons in the latter approach. It would be a lot of work to write down a theory in which particles (whose count isn't global) decide on corrections to their own trajectories that return themselves to a path similar to one along a smooth manifold even though they are "really" travelling along a non-smooth one, so long as you are trying to match well-tested results of General Relativity. (A theory which doesn't reproduce those results is maybe an interesting toy; "cheating" by using a nearly-but-not-quite minimal length that has no direct observables is an uninteresting toy, and is not really a good argument for the existence of Simulators (or Creator Gods or whatever).) In particular, the non-linear contributions of gravity will likely lead you into an explosion in the amount of knowledge that a particle would have to acquire in order to assess its trajectory; you'd probably also want to propose an explanation of how it goes about adjusting its trajectory when it discovers it's not on the "right" one. Don't forget to make this correct for all possible observers, including the ones that will see no particle and those that will see two or more particles. In practice, attempts to do away with infinitesimals of length that do not clearly fail to reproduce known physics also tend to produce infinities of state in matter and/or additional gauge fields, and the infinities don't succumb to information-reduction techniques like renormalization by power-set counting. If you're looking to encode that knowledge somewhere, like in a spacetime-permeating field, the gravitational field of General Relativity is right there and already serving that purpose in a non-toy theory that (in explorable parts of the known universe) behaves completely correctly with quantum field theories of matter, including The Standard Model. :-) Best of all, in a block universe model, the whole thing is "pre-rendered", and there is no difference between the block universe model and an initial-values-surface formalism in the presence of determinism. So you only have to fully render one frame, and you get all the others, past and future. (Quantum mechanics as we know it is deterministic -- that's unitarity.)