ark@rabbit.UUCP (Andrew Koenig) (05/03/84)
>> The laws of physics are descriptive, not prescriptive. In other words, >> the last sentence above is a misstatement. When the laws of physics >> say that the energy lost by (A) equals the energy gained by (B), they are >> not really saying that that MUST happen. Rather, they are saying what >> DOES happen, based on all the experiments that everyone has been able >> to conduct so far. This sort of law is always subject to revision in >> the light of new evidence (as Einstein's discoveries revised Newton's >> laws of motion), and is best considered as a description of the way >> the universe IS rather than how it must (or should) be. > I think this is mincing words. When you over-extend the analogy, of course > it will fall apart. The Law that is implied is a (the) true physical law > or laws that describe the motions of the billiard balls, not man's best guess > at the time. The point, which you are only emphasizing, is that the laws do > not of themselves *cause* anything. A true physical law describes what MUST > happen because that's the way things are; it is, in a sense, a "truth." > It's not like the speed limit, which we may care to break, or Newton's "Law", > which may be imperfect. I think this is what is meant by the analogy. > (I note that later on in his article, Andrew warns us about reasoning with > analogies...) I don't understand what analogy you say I am over-extending. I don't see any analogies in my paragraph above at all. If you are referring to something else I said, please do me the courtesy of quoting it. These arguments get a little hard to follow otherwise. Now, I'm not sure what you mean by a "true physical law." It sounds as if you are referring to some sort of principle that governs all events within its context, exactly and without variation. The trouble with such a thing is that if such a law exists, it is impossible for us ever to know that we have discovered it! For example, physicists believe very strongly in the conservation of matter+energy, because many experiments have confirmed it and no one has ever come up with an experiment that indicates otherwise. But it might be that matter+energy will only be conserved until noon next Tuesday, after which it will suddenly become possible to create energy from nothing. Short of waiting until next Tuesday, there is no experiment that can possibly disprove this! Barring fantastic advances in medicine, no experiment I can ever do can dispose of the possibility that matter+energy conservation will be abrogated sometime in 2142. (Please note that I have given an example, and not an analogy.) Newton's laws of motion describe the movements of the planets very well (among other things), but Einstein showed that certain corrections that made a difference mainly at very high speeds would describe things even better. He also devised an experiment to distinguish between these two descriptions. Has Einstein, then discovered the "true physical law" that governs the motion of the planets? It is impossible to know. All we know is that his is the most accurate description we have seen so far. >> In any event, it seems to me at least as plausible to say that the laws >> of nature are the cause of EVERYTHING as to say that they cause nothing. > This seems 180 degrees from the earlier paragraph. If they cause things, > then they are (in your words) "prescriptive." Which is it? Which is it? Depends on your definition of "cause." >> And what is the cause of this "pressure?" If everything must have a cause, >> so must this. If some things may be causeless, why not the universe? > Because you can't reverse entropy. If the universe is a closed system (I think the present view of most astrophysicists is that it is), then it is possible that the total entropy in the universe is constant. But you didn't answer my question. You claim that the universe must have been caused somehow, and that therefore God must have caused it. This claim is fallacious: Until you explain what caused God, you haven't explained anything by your claim, but have merely pushed the tough questions one level away. If it is all right to claim that God is causeless, then it is all right to claim that the universe is causeless, FOR EXACTLY THE SAME REASON (whatever it might be).