On Thu, Oct 16, 2014 at 12:01 PM, Bruno Marchal <[email protected]> wrote:
>> there is no logical reason or empirical evidence to think that the >> halting oracle exists in the physical world or even in Plato's abstract >> Platonia. >> > > > Time implement the halting oracle. There is a result by Schoenfield to > that effect, which shows that the fuincion computable with the halting > oracle are the function computable in the limit (in the computer scientist > sense of limit). > I assume you mean the halting oracle would work by making use of closed timelike curves, in other words a time machine. There is not one scrap of evidence that closed timelike curves exist in the physical universe and if they involve logical self contradictions as most think they do then they don't even exist in abstract Platonia. >> If you work in the fundamental It's also a big assumption that Platonia >> exists. >> > > > No, because it is the most least Platonia ever. You need only to believe > that 2+2=4 is true independently of you. > If the physical world didn't exist and there wasn't 4 of anything and never has been, would 2+2=4 have any meaning? And even if it did would it matter, who would be around to understand that meaning? You have always just assumed that mathematics is more fundamental than physics and maybe it is, but with the recent discovery that information is physical we can at least question that assumption. It's also odd that computers need to be made of matter not abstract stuff from Platonia before they can actually do anything intelligent and presumably before they can become conscious; but I don't think anyone knows yet which is more fundamental, the real numbers or superstrings. John K Clark -- 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.
