On Sat, May 12, 2018 at 4:21 AM, Bruno Marchal <marc...@ulb.ac.be> wrote:
> > I use computer for “universal Turing machine”. That notion assumes (and is > Turing-equivalent with (very) elementary arithmetic). > A Turing Machine knows no theories and it operates under the laws of physics not because it assume them but because it has no choice in the matter. >> >> Computers are made of matter that obeys the laws of physics, > > > Physical computer. > A Turing Machine is a physical computer and a Turing Machine is the only type of computer that there is; even a virtual computer needs a Turing machine somewhere down the line . > > > But I do not assume > [...] > A Turing Machine doesn't give a damn what you do or do not assume, it just keeps on cranking away according to the laws of laws of physics. >> >> when the voltage on one of the inputs of the microchip is positive >> physics orders it will do one thing and when the voltage is negative it >> will order it to do something different. By picking A you are in effect >> saying you have looked at the pattern of voltages physics told the >> microchip to have and you have interpreted that pattern to to be a even >> number that is not the sum two prime numbers, and you believe what physics >> is telling you even if the axioms of Number Theory says such a number can >> not exist. > > > *> I have not assume physics anywhere,* > That's OK, physics doesn't assume you either. But you have said if the ZFC axioms say one thing and the computer says the opposite then you'd believe the computer and not the axioms, and that is what any sane man would do because theories come and go but physics always tells the truth, > *> so this does not make any sense.* > Then how can you make sense out of ANY post from ANYBODY on this list? How can you reply to any post when its just a pattern of voltages on the microchip inside your computer? > >> >> By picking A you are saying physics is more trustworthy than any set of >> axioms could be, if there is a contradiction between the two it is the >> axioms that need to give way not physical law because although >> >> physics can be weird it has no self contradictions, but man made axioms >> can. > > > > > Physical theories can be contradictory. > I f two physical theories try to explain the same phenomena then they are ALWAYS contradictory, otherwise they'd be the same theory, but at least one of those theories must be wrong and that's where experiment comes in. Physics (not to be confused with physical theories) is never contradictory and will always tell you the truth, I would even say its the very definition of truth. > > > And physical reality is not an assumption available at the start. > To hell with assumptions! If I walk across a bridge it won't stay intact if I make one assumption and collapse if I make another assumption. The bridge will either collapse or it won't. The bridge doesn't care what I assume and neither do the laws of physics. >> >> A real machine will NEVER operate contrary to the laws of physics, > > > *> In which theory.* > What in the world that mean?? In which theory what? > > > *You are using implicit metaphysical assumption.* > A collapsed or intact bridge is not metaphysical nor is it a n assumption, it is matter operating according to the laws of physics. >> >> but a set of axioms will ALWAYS be inconsistent or incomplete or both. > > > > ** > *If a theory is inconsistent, it is obviously complete. * > Yes, you're right, my error. If I'm working with inconsistent axioms then I can prove all true mathematical statements therefore its complete, the only trouble is I can prove all false mathematical statements are true too. In a lecture on logic Bertrand Russell said a false proposition implies any proposition. A student challenged him on that and said ”In that case, given that 1 = 0 prove that you are the Pope.” Without hesitation Russell said ”Add 1 to both sides of the equation: then we have 2 = 1. The set containing just me and the Pope has 2 members. But 2 = 1, so it has only 1 member; therefore, I am the Pope.” > *> If a physical computer (assumed to have no bugs in it) can find an > even number not being the sum of two prime, then that number can be find by > very elementary arithmetic,* > And you already said, quite wisely, that if you had correctly used the ZFC axioms to produce a proof the Goldbach Conjecture was true but then a computer found a number that violated Goldbach you would place the blame on the ZFC axioms and not on the laws of physics the computer operates under. So like me you are saying it is physics and not axioms that is the ultimate judge that decides what it true and what is not 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
