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P.O. Box 797 Sonoita, AZ 85637-0797 May 16, 2000 Prof. David Chalmers Philosophy Department Room 213, Social Sciences Building University of Arizona Tucson, AZ 85721-0027 Dear Prof. Chalmers: When I read the article "Quantum Consciousness" by Dan Huff in the April 6-12 Tucson Weekly, "it was deja vu all over again", this time in the correct meaning of the phrase (with proper credit to Yogi Berra). When I was six years old, I asked my father why the night sky wasn't white with stars. When he looked at me quizzically, I asked if space was infinitely large, and he said yes. Then I asked if there were an infinite number of stars in space, and he said yes (something we now know not to be true). So I said that if you look in any one direction, you should eventually see a star, so you should see light from that star, so why isn't the night sky all lit up? I was extremely disappointed to learn at age six that my father didn't know everything, and my father, a mechanical engineer by training, had an interesting problem to stew on. I was even more disappointed later on to learn that in 1826, Heinrich Willhelm Olbers (a German physician and amateur astronomer) had made the same observation. The second "Hey, I already thought of that!" experience I had was when I read the quote from you saying that modern physics seems to have left consciousness out of the equation. That was just too much. A couple years ago, I had seen a series of programs on PBS in which they sat a few people around a table and got them talking. The group included Stephen Toulmin and Daniel Dennett. I ordered Dennett's book Consciousness Explained but between work and starting a new business on the side, I haven't had a chance to read it yet. The Tucson Weekly article finally goaded me into action. When I was a physics major at Brown University in the late 1960's (Class of 1970), I took enough philosophy courses to be only two courses short of majoring in philosophy. I even considered changing majors at one point, as my grades in philosophy were better than those in physics. I went on to graduate school in physics and astronomy, and now work at the US national observatory (National Optical Astronomy Observatories) in Tucson on Cherry Ave as a technical manager overseeing the development of instruments for large telescopes. As an aside, seeing Toulmin on TV made me realize how young he must have been when he wrote An Examination of the Place of Reason in Ethics in 1950! Or was the person I saw on TV his son, a distant relation, or no relation? The philosophical problem that I "invented" for myself at the time was explaining consciousness. There were no books or papers on it back in the late '60's that I knew of. I was interested in combining Descartes, the problem of other minds (in an offhand way), most of epistemology, physics, and philosophy of science. But before that, as a freshman, I had heard of Roderick Chisholm and how he had been a student of Wittgenstein, and how great a philosopher he was. I took his course on metaphysics and learned a lot and enjoyed it. I took epistemology from another professor, and he assigned, among other books, Chisholm's Theory of Knowledge" in which he easily demolished the sense data theory ("little man in a theater of the mind watching some kind of internal movie screen") and replaced it with his "theory of appearing". As far as I could tell, the "theory of appearing" could be stated as "it just happens directly and immediately, and we don't know how". After hearing all the local Brown hype about Chisholm and then reading his monograph, I was bitterly disappointed. Did I miss something? Was this guy so brilliant that he laid out the whole theory right before me and I was just blind to it? So I read the book again. I couldn't believe that this passed for great scholarship. I don't mean to denegrate Chisholm or to belittle his contribution, as this is a tough problem, the sense data theory was a red herring that needed to be put to rest, and he did get things back on track -- it is direct and immediate. But my training in physics told me that "pure" philosophy had reached the end of the line for this problem. I forget if it was in response to Chisholm's book, but sometime for that course, I wrote a short paper outlining my theory, which was that the conscious experiences we have are not part of today's physics Standard Model (they didn't call it that in 1969). I believe that, e.g. for sight, photons bounce off an object, impinge on our cornea, and are focused on the retina where zillions of neurons fire, and electro-chemical reactions occur and lots of interesting processing gets done, which continues through the optic nerve on into the brain. All this has to occur for sight to occur, they are necessary and sufficient, they cause sight, but they are not sight. The ontology is different. The experience is not atoms and molecules and quantum mechanics, the experience is red and green and blue. That's what we have to explain. My paper had two simple arguments. The first is causal: If A causes B, then A can not be identical to B. All the neurophysiology stuff that is so popular today, the quantum mechanics, etc. is what causes our experiences (like it or not, we are grounded in the physical world, our bodies are made of protoplasm). They are not the experiences themselves. You can follow the whole chain of events through the brain, then something happens that goes beyond what our physics can encompass. The second argument in my paper was: If A has a property it does not share with B, A and B cannot be identical. This argument was used by Chisholm and others as an argument against the sense data theory, but I think it also applies to experiences versus things in the world of Standard Model physics used to explain experiences. How can the experience of redness and some quantum mechanical event be the same thing if they don't share all properties? I don't see any wave functions or Feinman integrals or charm or superstrings or rolled-up dimensions when I see a red ribbon. Penrose is a very bright fellow, but he should stick to his famous diagrams used in General Relativity. I assumed I was the only one interested in this question at the time, and let it drop. I continued my studies in physics and astronomy, spent 18 years in Washington, DC most of it in the aerospace industry in software and program management, and now I try to keep small teams of astronomers and engineers on schedule and under budget as they build boxes that capture and record photons from distant galaxies. One course I took at Brown was philosophy of science. If you sit in on the first lecture of freshman physics, you have all the physics you need to understand if Penrose is correct. What any scientist does is build a model. A model is like a road map. A road map is not the same size as the roads on it, it doesn't contain all the buildings, plants, etc. along the way. It is designed to serve one particular purpose, and that purpose it serves well. Other purposes it does not serve well. Physics starts with simple concepts of mass, force, charge, length, and time to construct a simple road map of the physical road. There is no "red", "blue", "trumpet", "hot", "pain", etc. in this model, just as there are no plants, houses, etc. on a road map. Trying to use the Standard Model of physics to explain consciousness is like trying to use the Mobil Travel Guide to find a tree next to your home. It is natural for physicists to try, as that is the first impulse of a scientist -- to extend the current model to new data -- but I think scientists should spend as much time thinking about what they are doing (the "meta" of their work) as they do doing it. They should understand how the current theories came to be, where they have proved to be successful, and that their limitations are. As a student, I had trouble understanding the Copenhagen interpretation of quantum mechanics, and I confess I still do not understand it. As far as I am concerned, it is so much nonsense promoted by a rather strong personality at the right moment, almost a an accident of history. An alternative interpretation that is now receiving some attention is an information theory approach. A recent obit in Physics Today discusses the career of one who advocated this approach, and I think that it will gain adherents in coming decades as physicists work in more interdisciplinary ways with electrical engineers on neurophysiology and other such problems. The reason I say this is electrical engineers understand information theory in terms of noise on communications lines, and what are neurons if not communications lines with built-in processing? Electrical engineers are very comfortable with modelling these things. So I would caution the consciousness community, for a variety of reasons, against going too far down the path that Roger Penrose is pursuing. From the newspaper article, it sounds as though the field that I "invented" (I hope you take this as the joke it is intended to be) 32 years ago has come a long way and has left me far, far behind. I'm sure this letter has contributed nothing new you haven't heard or thought before. If there is anything in this letter that you find worthy of discussing, you can reach me at my Tucson office during business hours at 318-8519. Sincerely, Mark Trueblood