On Friday, February 7, 2014 7:33:28 PM UTC-5, Liz R wrote: > > On 8 February 2014 07:48, Bruno Marchal <[email protected] <javascript:>>wrote: > >> >> On 06 Feb 2014, at 21:43, LizR wrote: >> >> Because Turing universality is a mathematical notion. >>> >>> It has nothing to do with physics. >>> >>> I must admit I was quite surprised by this. I thought you generally >> argue that physics can be extracted from comp, and TU is part of comp >> (isn't it?) >> >> Ys, but that is why it is meaningfull to say that we derive physics from >> zero physical assumption. >> >> We derive physics from TU, which is defined in pure arithmetic, and has >> indeed no relation at all with physics *in his definition*. It involves >> only 0, successor, and the * and + laws, nothing else. >> >> Of course arithmetic and TU has something to do with physics, *at some >> level*, assuming comp, and well, in the psychology or theology of the TUs, >> which is itself derived from arithmetical self-reference. >> >> But this means that physics has some plausible relation with the UT. The >> UT itself, at his definition level, is a purely arithmetical notion. >> >> OK? >> > > Yes, of course. I was getting the cart before the horse, as they say. TU > has nothing to do with physics but physics may have something to do with TU. >
How do you know it has nothing to do with physics? It seems clear to me that the behaviors of integers, memory, etc. are rooted in familiarity with a particular macroscopic physics. Building a Turing machine only out of emotions or fog or empty space is not possible. -- 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/groups/opt_out.
