On Tue, Oct 9, 2012 at 10:28 AM, Craig Weinberg <whatsons...@gmail.com> wrote:
>> There is no assumption that our knowledge of physics is complete; in >> fact if there were that assumption there would be no point in being a >> physicist, would there? As a matter of fact I believe that the basic >> physics of the brain has been understood for a long time and I >> challenge you to point out one thing that has been discovered in >> neuroscience which would surprise a chemist from the middle of last >> century. > > > What you are saying is 'nobody thinks physics is complete', followed by > 'everybody knows that the physics of the brain has been complete for a long > time'. No, I said there is no *assumption* that our knowledge of physics is complete. Obviously, it isn't complete, since physics is still an active field. However, as a matter of scientific fact, there is no evidence that anything more exotic than organic chemistry is going on in the brain. There are many, many discoveries in neuroscience every year but none of them could be described as new physics. New physics in the brain would, for example, be a discovery that dark matter is instrumental in nerve conduction. But so far, it's just organic chemistry. > This not only supports my point, but it brings up the more important point - > the blindness of robustly left-hemisphere thinkers to identify their own > capacity for denial. For me it's like a split brained experiment. I say 'the > problem is that people think physics is complete' and you say 'no they > don't. You can't show me any signs that physics of the brain isn't > complete.' Total disconnect. You'll keep denying it too. Not your fault > either, apparently, that's just the way a lot of intelligent people are > wired. I have no idea if it's possible for people to consciously overcome > that tendency...it would be like glimpsing yourself in the mirror before > your image actually turned around. Neuroscience has been a very large, well-funded field for many decades. Can you point to any experiments at least hinting at new physics? >> But that is not relevant to this discussion. The question is >> whether the physics of the brain, known or unknown, is computable. If >> it is, > > > If the physics of the brain is incomplete, then how could we say whether it > is computable or not? To me, the color red is physical, so that any > computation of the brain has to arrive at a computational result that is > [the experience of seeing red]. I don't think that is remotely possible. As I have said many, many times in these discussions, I am happy to assume for the sake of argument that consciousness is *not* computable. The question being asked is whether the physical movement of the parts of the brain are computable. That means given a complete description of initial conditions, an adequate model and sufficient computing power, is it possible to predict the physical movement of the parts of the brain? This does *not* mean it is a practical likelihood, only a theoretical possibility. Indeed, an actual Turing machine, used in the formal definition of "computable", is *not* physically possible. OK? If consciousness is not computable, and consciousness affects the physical movement of the parts of the brain, then the physical movement of the parts of the brain is not computable. OK? To put this another way, we would observe neurons (and I guess other cells too, if consciousness is all pervasive) doing stuff *contrary to the known laws of physics*. For if neurons only did stuff consistent with what we know about organic chemistry, and organic chemistry is assumed to be computable, then the physical movement of the parts of the brain would be computable too. OK? >> then in theory a computer could be just as intelligent as a >> human. If it isn't, then a computer would always have some deficit >> compared to a human. Maybe it would never be able to play the violin, >> cut your hair or write a book as well as a human. > > > The deficiency is that it couldn't feel. It could impersonate a violin > player, but it would lack character and passion, gravitas, presence. Just > like whirling CGI graphics of pseudo-metallic transparent reflecty crap. > It's empty and weightless. Can't you tell? Can't you see that? Again, I > should not expect everyone to be able to see that. I guess I can only > understand that I see that and know that you can see a lot of things that I > can't as well. In your mind there is no reason that we can't eat broken > glass for breakfast if we install synthetic stomach lining that doesn't know > the difference between food and glass. Nothing I can say will give you pause > or question your reasoning, because indeed, the reasoning is internally > consistent. Again, I have assumed for the sake of argument that a computer cannot feel. But if the movement of the parts of the brain is computable, the computer will be able to behave just like a person, in every respect. After prolonged interaction with it an observer would guess that it had feelings even though it did not. So do you agree that a computer could masquerade as a person with feelings or do you think you would be able to see through its deception? >> This is apparently >> what you think, but you have not presented any evidence for this >> non-computable physics. It's just an assumption you make. > > > We are the evidence. Our own consciousness is an assumption that we have no > choice but to make. The capacity to judge evidence supervenes on the > assumption of consciousness, of the color red, of self and other, symmetry, > etc. Evidence is wayyyy down the list of derivative effects. Where is the laboratory evidence of non-computable physics? -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to firstname.lastname@example.org. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.