One has to be careful with nearly all the "impossibility" theorems: Arrow's voting, the speed of light, Godel, Heisenberg, decidability, NoFreeLunch, ... and so on.
To tell the truth, Godel .. it seems to me .. says to the practicing mathematician that the axioms have to be very carefully chosen. Its sorta like linear algebra: a system can be over constrained .. thus contain impossibilities, or under constrained thus have multiple solutions. But all I'm hoping for is any attempt to make the words Nick and others have be as precise as a computer language. If this is the case, then we can use the lovely computation hierarchy from FSA, to CFL to Turing/Church. But then, most mathematicians know none of this structure either. Sigh. I wish philosophy had the same constraints where bugs could be found. On the other hand, ambiguity can be a huge plus, as any spoken language shows. -- Owen On Tue, Apr 16, 2013 at 3:39 PM, Barry MacKichan < [email protected]> wrote: > Curious. Isn't the proof of Godel's theorem a special case of this? > > As I understand it, the proof is this: > > Consider the statement: This theorem is not provable. If it is false, the > theorem is provable. Since 'provable' implies true, this is a > contradiction. Therefore the theorem is true, which means it is true and > not provable. > > The genius in Godel's method is that he created an isomorphism between the > domain of the previous paragraph, and arithmetic, and the isomorphism > preserves truth and provability. Thus the above theorem corresponds to a > statement in arithmetic that is true and not provable. What is this > statement, you might ask. Well, evidently it is far to complex to compute > or write down (although it would be interesting to see if more powerful > computers or quantum computers would change this.) > > Anyway, that true but non-provable theorem shows that number theory (aka > arithmetic) is incomplete -- that's the definition of incomplete in this > context. > > --Barry > > > On Apr 16, 2013, at 10:25 AM, Owen Densmore <[email protected]> wrote: > > On Sat, Apr 13, 2013 at 2:05 PM, Nicholas Thompson < > [email protected]> wrote: > >> Can anybody translate this for a non programmer person? >> >> > Nick's question brings up a project I'd love to see: an attempt at an > isomorphism between computation and philosophy. (An isomorphism is a 1 to > 1, onto mapping from one to another, or a bijection.) > > For example, in computer science, "decidability" is a very concrete idea. > Yet when I hear philosophical terms, and dutifully look them up in the > stanford dictionary of philosophy, I find myself suspicious of circularity. > > Decidability is interesting because it proves not all computations can > successfully expressed as "programs". It does this by using two infinities > of different cardinality (countable vs continuum). > > Does philosophy deal in constructs that nicely map onto computing, > possibly programming languages? > > I'm not specifically concerned with decidability, only use that as an > example because it shows the struggle in computer science for modeling > computation itself, from Finite Automata, Context Free Languages, and to > Turing Machines (or equivalently lambda calculus). > > I don't dislike philosophy, mainly thanks to conversations with Nick. And > I do know that axiomatic approaches to philosophy have been popular. > > So is there a possible isomorphism? > > -- Owen > ============================================================ > FRIAM Applied Complexity Group listserv > Meets Fridays 9a-11:30 at cafe at St. John's College > to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com > > > > ============================================================ > FRIAM Applied Complexity Group listserv > Meets Fridays 9a-11:30 at cafe at St. John's College > to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com >
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