Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!psuvax1!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: zds-ux!gerry@uunet.uu.net Newsgroups: sci.nanotech Subject: Re: "The Emperor's New Mind," a book review Message-ID: Date: 13 Jan 90 04:50:18 GMT Sender: nanotech@athos.rutgers.edu Lines: 136 Approved: nanotech@aramis.rutgers.edu In article merkle@parc.xerox.com writes: >His position is perhaps best summarized by his own conclusion: >"...science seems to have driven us to accept that we are all merely small >parts of a world governed in full detail (even if perhaps ultimately just >probabilistically) by very precise mathematical laws. Our brains >themselves, which seem to control all our actions are also ruled by these >same precise laws. The picture has emerged that all this precise physical >activity is, in effect, nothing more than the acting out of some vast >(perhaps probabilistic) computation -- and, hence our brains and our minds >are to be understood solely in terms of such computations. Perhaps when >computations become extraordinarily complicated they can begin to take on >the more poetic or subjective qualities that we associate with the term >'mind'. Yet it is hard to avoid an uncomfortable feeling that there must >always be something missing from such a picture." I just read _Cosmic_Blueprint_ by Paul Davies (I think that's right, but I don't have the book here), which covers some of the same area, and references Penrose in a few places. From your review of Penrose' book, Penrose may be more driven by the "uncomfortable feeling" than Davies is, and Davies is very careful to distinguish between stronger claims that he can ground and speculations or more mystical interpretations, etc. He demonstrates in a number of ways why the extreme reductionism (as in the first quoted sentence above) cannot be correct. In essense he is taking exception to the idea that "nothing can come from nothing," which he points out is the basis for a number of philosophies that must have the universe created in a state of order or perfection and have it degenerating from there. Note that this is at odds with Big Bang theories where the initial universe has a high degree of symetry, a property of thermodynamic equilibrium. He claims that the emergence of order in successively higher levels of organization is a second "creative" arrow of time running in the oposite direction from the thermodynamic one. Part of this idea is that each level of order can have its own systemic laws that are not derivable from the principles of lower levels of order. In other words, the other sciences are not reduceble to physics even with exact initial conditions and infinite computer power to simulate it, or that biology is not enough to predict the behavior of organisms that have minds. >"Since there ARE neurons in the human body that can be triggered by single >quantum events, is it not reasonable to ask whether cells of this kind >might be found somewhere in the main part of the human brain? As far as I >am aware, there is no evidence for this. The types of cell that have been >examined all require a threshold to be reached, and a very large number of >quanta needed in order that the cell will fire. One might speculate, >however, that somewhere deep in the brain, cells are to be found of single >quantum sensitivy. If this proves to be the case, then quantum mechanics >will be significantly involved in brain activity." I don't understand the necessity of linking quantum events to the higher level phenomenon. Even very simple chaotic systems have enough sensitivity to initial conditions to make them essentially unpredictable, so all you need is some kind of "synchronistic" effects to maintain the unity of higher level events. >What is consciousness? I won't venture a definition, but unless we are >prepared to throw away the known laws of physics (even though there is no >evidence that these laws are incorrect as applied to the human brain) the >behavior of the human brain can be modelled on a sufficiently large >computer. Is such a model conscious? Well, it would certainly pass any >objective test that we could possibly devise, by definition. And even >Penrose agrees that consciousness, whatever it might be, has objective >behavioral correlates. Which means that such a model would satisfy Penrose >(though he would no doubt grumble about it). No, simulation of the brain may be possible, but not on the level of physics, and probably not on the level of neurons either. It is interesting to see how this type of discussion is related to the question of whether computers can think. The reductionist claim that everything is physics, therefore we can simulate it, and some philosophers complain that there is something special about life and/or man's conscousness that makes this impossible. Various approaches are used, but there are always some links in the logic that are questionable. Davies' claim that there are "emergent" phenomenon leaves open the possibility of new types of organization, for example a thinking computer, or that the products of nano-technology could truly take on a life of its own. >Penrose is claiming that no such computer program exists. He is claiming >that the presently known laws of physics are fundamentally wrong when >applied to the human brain. He presents no single shred of evidence in >support of these propositions, and his arguments against the generally >accepted philosophy of the mind are fatally flawed. This is what I refer to above in "some philosophers complain. . .", and as I said there are often questionable lines of reasoning. >At root, Penrose wants the reassurance that humans are inherently superior >to computers. Thanks to Copernicus, we are no longer at the center of the >universe. Thanks to Darwin, we are descended from apes. Now, we must face >the reality that nothing fundamental separates us from computers. Yes, I think this is another move away from a me-centered or us-centered cosmology. But I also suspect this movement is basic to the "maturing order" of the world. It can be observed in the maturing of a child, why not also in the maturing of a culture. >What, then, prevents computers from becoming our superiors and taking over? >If we admit that computers can be conscious, haven't we also admitted our >own doom? Some quite competent scientists have argued that this is our >fate -- to be replaced by vastly superior beings designed by our own hands. I suppose, but it's likely to be a long way off. I just don't think we have a very good handle on the nature of the complexity of minds or living organisms. It should be close because we learn more at an every increasing rate, but there is a vast uncharted abys between here and there. And yes, this fear of possible futures can motivate denial. For me, the fear is that we won't get wise fast enough to control what we already know. Futures like "grey goo", life-less in the sense of uninteresting, but active enough to take over the environment, or alternatively the first intellegent machines are built for a "defense net" as in The Terminator that has no other purpose but to kill humans until they are gone. Maybe grey goo is not so bad, more like going back to the single cell era; potential for "higher" forms to develop again. >Yet facing reality is usually safer than hiding from it. If we pretend >that computers will never equal the wonderful stuff of which our minds are >made, then we are running away from the fundamental problem and increasing >our peril. The strategy of the ostrich does not appear prudent. Yes, this is also Drexler's position on nano-technology. Actually more like, "if we don't do it openly, someone (military?) will do it in secret, and then where will we be?" >It does mean that we'd better think about where we're going and what we >want. This is true of present technologies, but more so with stuff like AI and nano-tech. Gerry Gleason