On 26 August 2015 at 17:21, Peter Sas <[email protected]> wrote:
> Hi guys and girls, > > I'm sure this question has already come up many times before, but it's an > important one, so I guess it can't do any harm to go over it again. > > If the universe is thoroughly computational, what are the computations > 'running' on? What I especially like to know is what options are discussed > in digital physics. So far I have encountered only the following > possibilities: > > (1) Mathematical platonism: all natural numbers, and all mappings between > them (i.e. all algorithms), simply exist in 'Plato's heaven', including > those algorithms that compute our universe. The simple non-spatiotemporal > existence of those algorithms is enough to 'instantiate' a spatiotemporal > world. This type of solution can be found in Tipler, Tegmark and our own > Bruno Marchal. > I thought Tipler's theory is that there will be an actual physical computer that will be able to do all possible computations as the Universe collapses - although since he came up with the idea it has been shown that the Universe won't collapse in the required way. > Major problem: the hard problem of consciousness. > Why is the Hard Problem of Consciousness a problem in the computerless computation scenario? > (2) Simulation by an advanced civilization: Our universe is simulated on a > physical computer build by a superior intelligence. Nick Bolstrom has > explored this option and found it quite probable. I don't know about that, > but as a general approach to digital physics it fails. If we want to > understand the physical universe in terms of computation then it is > circular to postulate a physical hardware on which the computations are > running. > > (3) Or perhaps it is not circular? This third option sees the physical > universe itself as a (quantum) computer (or cellular automaton) computing > its own future. Thus its present state is the input and the temporally next > state is the output. Isn't this how David Deutsch approaches it? I am not > very clear on this option. The major problem seems to be that you have to > presuppose an initial state of the universe that itself is not the result > of computation, just to avoid an infinite regress. Or you accept the > regress and say the universe exists eternally (but this is problematic in > light of the big bang). But then you still have to explain why the universe > exists eternally. And then the explanation must still fall outside the > computations going on in the universe... > > (4) The computations that yield our universe run on a platform that exists > somewhere else, in another dimension that is principally inaccessible to > us. Ed Fredkin has embraced this 'solution' and calls this other dimension > simply "the Other" which has a theological ring to it. I don't like this > option, but it seems to be the most straightforward one. > > Any thoughts or corrections? Are there some options I haven't discussed. > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
