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Showing posts from October, 2008

switching from the higher spheres to the higher symmetries

Okay: this may be a hot idea, or it may be plain nutty--but here goes: Aristotle had the notion of the sublunar sphere and all within it being moved by the higher spheres. And the natural state of the motion of these spheres was motion rather than rest. We certainly don't have spheres any more, but from the point of view of physics (i.e., abstracting from biological questions) we do have a higher and lower. The higher has a kind of circularity about it. And a kind of simplicity about it (just as the movement of the spheres was thoguht to be circular. And the higher does drive the lower (at least until we get to questions of life). But the higher in this case is not above our heads. And it is not in any sense "macro" or large. Rather, it is micro. Yep, (at least if Stephen Barr is right) the smaller, less evident purely physical (i.e, apart from biological) processes have higher symmetry than the larger, more evident ones. Just as a marble (sez Barr) has more sy

projectile motion, natural place and teleology

Thesis: Aristotle's notion that the upward motion of a projectile is against nature requires not only a teleological view of nature, but also a geocentric understanding of that teleology. A teleological view of nature, however, need not be geocentric: in which case, a teleological account of projectile motion need not be antiquated. Background: For Aristotle, the earth's center is the target of all bodies made of earth (air and fire, which are not made of earth, have the heavens as their target). If we simply release earthly things, they head toward that target with a rectilinear movement. They cease this movement only when they have encountered an impediment (or when they have reached their target, which would require, I suppose, digging a hole to the center of the earth, etc.). Heavenly bodies, on the other hand, have no targets, but they do have a purpose, which is to move. And these movements themselves are target-like inasmuch as one heavenly body moves in definite,

natural place replaced by natural movement/acceleration

Thanks to Tim, I think I got an iddee biddee grasp of the curvature of time-space. It seems that Einstein's talk of "curved space" amounts an analogy between inertia and gravitational pull. That is, the Einsteinian recognition of the fact that things naturally accelerate toward each other as long as no (non-gravitational) force intervenes is analogous to the Newtonian recognition of the fact that things naturally move at a constant speed and in a constant direction with respect to each other as long no force intervenes. And just as a Newtonian would deny that a force is involved in inertia (F=ma means that when 'a' or acceleration equals zero, 'F' or force equals zero), so too an Einsteinian (that would be all of us) denies that a force is involved in gravitation. To make gravitation "look like" inertia, we might say that space/time is curved. That is, just as we expect a projectile (not affected by extrinsic forces) to move at a constant speed t