September 4, 1998
Andrew Baird
Somewhere on the AT
Damascus, Va.
24236
Dear Andrew:
I did not sent mail to Clinton due to a post office thing, but I packed the Clinton things into the Harper's Ferry or the Tyro box so you should have received everything.
As far as the philosophy goes I agree with your opinion about "WHY?" It is in the realm of theology about which I have little to say. Theologians, however, have much to say based on their assumptions (which they call faith) and everything follows logically from that I suppose. I can still ask "why?" but on a less fundamental level. Why does the radio work today where it did not work yesterday, or why can I hear a program? Not a theological why, but something less. "What is the meaning of life" is an OK question because one may be able to answer this to ones satisfaction and that is all that is required. Of course for the religious fundamentalists this is an easy question to answer. Getting them to leave us alone is another matter. I put all this in the same category as does Matt. There are similar questions in science. There is a whole philosophy of science and to me it has always been an unproductive thing to discuss. On the other hand, one can have fun with some of this stuff so long as one does not get carried away.
These questions of the interpretation of certain areas of physics may well be important in that, who knows, they may lead to something new. For example, all the information about a physical system (could be a person for that matter, but really not. The theory is OK, but the analysis more detailed. You cannot through a person at a wall with two small holes it in and expect the person to remain a person!) is contained in the "wave function" of quantum mechanics. We can have two identical states of a system, one and two say, and prior to a measurement on this we do not know which exists. The way quantum mechanics expresses our lack of knowledge is to say that the system (molecule, electron, etc.) is a 50-50 mixture of both one and two like (1/2)(one + two). When a measurement is made we will know if it is one or two exactly so we get (one) lets say. Now the system has jumped suddenly from (1/2)(one + two) -> (one). This seems like a paradox. How can a system move faster than the speed of light and suddenly change because of a measurement? They're a bunch of things like this in quantum mechanics where the interpretation of the meaning is up for debate. On the other hand, quantum mechanics works. That is, we can do experiments and we can calculate things and they will agree to fantastic accuracy and precision. We can also spend lots of time debating the philosophic issues, which I have personally placed in the same category as "meaningless questions." If instead if debating the philosophical questions (which can be fun) we instead use the stuff, we can do actual practical things. Example: if a single photon is emitted by a laser pointed at two identical holes placed symmetrically with respect to the laser beam and we place a photon detector on the other side that can detect single photons what happens? As the photon approaches the hole we cannot tell beforehand which it will go through. On the other side the detector will detect the photon at a certain position. There will be a single spot. Another photon goes and another spot is formed. Gradually, as more and more photons are fired at the two holes an interference pattern is formed on the detector side. The detector detects an interference pattern. The photons have behaved like a wave (like water waves incident on two slits in a ripple tank) and interfered with them selves. On the other hand, if we made some kind of measurement to tell which hole the photon was going to go through we would destroy the interference pattern. This is an essence of quantum mechanics and can be represented using the (1/2)(hole one + hole two) expression. Without the measurement on the laser side of the partition the photon goes through both holes simultaneously and is represented by (1/2)(hole one + hole two). The amplitude of the signal is the square of this quantity or (1/4)(hole one + hole two)^2 = (1/4)[hole one^2 + hole two^2 + 2(hole one)(hole two)]. The 2(hole one)(hole two) represents the interference while the terms like (hole one)^2 represents the amount of light through hole one. This is an experiment that can be done and has useful application (This kind of thing is part of the basis of quantum computing) while the philosophy gets one no where but an argument. I don't know how far you can push the analogy with your dissertation on "why?" but there are certainly similarities if not identity.
Well, the idea of carrying a lighter weight and therefore having less stress on the running shoes as well as ankles and knees seems sound. The people carrying 60 lbs. have different problems. I have always felt that "Lighter is better" to paraphrase that auto commercial. If it is necessary to carry 60 lbs. then OK. I think the idea of the bivy is also important. It weighs just 1 lb. yet is waterproof and has that insect screen. Otherwise a lightweight tent is useful due to all this rainy weather. I hiked many years in the Sierra Nevada and never used a tent. In fact there was a saying that it "never rained at night in the Sierras." Then, of a sudden, that seemed to change so I bought that tent. Swore a lot prior to that! That tent was state of the art at the time, but now is too heavy. When the guy in EMS showed me the bivy I was sold, but I was not sure how you would like it. He had hiked the AT from S to N. Said he would not carry food next time, but buy it along the way. Is that practical? He also had a hiking buddy, but they had different sleeping styles and so split up. People worry about you doing this alone, but it sounds as though you run into to folks and there are always the post offices. It surely has been an experience.
Don't wear your self out just for the sake of a schedule. It is better if you are late arriving at a mail drop than if you are early. I have seen none of the pics sent to NH and do not know what has become of them. I am going to stop the forwarding as there are things sent to me from Brown that I do not get either.
I had lunch with student advisees and one of them had been just about everywhere in europe so it seemed. He went to Moscow and make some kind of circular trip hitting St. Petersburg and then the cheapest way home seemed to be by local trains to Hong Kong by way of Siberia. He had climbed the Matterhorn and did a bunch of other stuff. These were his summers. I met Carie Neilson, one of the Environmental Chem Lab people and a friend of Rebbecas, who plans to fly around the world. There is some kind of airline ticket that, so long as you keep going either east or west, allows as many stops as you wish. You can go north or south, but always making progress in one easterly, or westerly direction. Her father had loads of frequent flyer miles and is giving them to her so that she only has to have funds for the food and lodging. Yet another adventure.
Keep the letters coming. They are interesting.
Love,
Dad