from the glacier

Sir James Jeans wrote a neat little book in the Forties called "Physics and Philosophy" that I just finished. Interesting. But there are a few points that I would like to bring out for those who will most likely never read this book. They bring about the questions of the possibility of a (as I would like to create) "science of physical method". First we attend to the problem of scale.

Man is, well, man-sized. Pretty big compared to atoms. Pretty small compared to nebulae. Oddly, however, man occupies the central size. Ratio: atom : man :: man : nebula. Now look at "classical physics" of Newton. Gravitation (in its mathematical form) works well enough to land some people on the moon, and predict missile trajectories well enough to assure global destruction (from the military aspect). But as things get smaller, Newton breaks down. Even if there was such a thing as a "force" of gravity, which modern science denies, the action of electrons around a nucleus evade the results predicted by Newton, as does the diffusion of light. Further, although we predict how long it will take my empty beer bottle to go from my hand to the garbage can (given my height and G) we still (as Einstein points out in one of the appendices to "Relativity") can't precisely locate where the perihelion of Mercury is supposed to be. Scale. It all resolves to a problem of scale. I guess it seems logical from a homocentric point of view to put us in the middle, as it is we who observe, but I don't think it is an accident that when we change scales the number that work for us don't work in another frame of reference. Let's examine the larger frame of reference first, because more of "my public" is familiar with Relativity.

First of all, Newton assumed absolute time and space. Not true. Space and time become conceived of as relative to bodies - simply. This makes more logical sense anyway. Einstein shows the General Principle pretty well, every law in K applies to K prime. If you read the appendix on Minkowski space and the mathematical ramifications of the Lorenz transformations, you see that the proof that light is propagated with a finite (though huge) speed, implies that the "time variable" depends on the motion of the frame of reference. Space and time can no longer be thought of as X,Y,Z and T (the red-headed stepchild of mathematical physics' variables) but rather as X1, X2, X3, and X4, a time-space continuum. This replaces the theory of "forces" in the way that Newton wrote about them. What is the difference between "love and strife" a la Empedocles, "gravitas" of Newton, the pagan belief in moon gods, and Angelic Heavenly spheres? NOTHING. But as soon as you replace time and 3D space with a continuum of space-time, you lose inverse square law as a method of description. To quote:

Re-read to digest if necessary. All that is shown is that all moving bodies travel in straight lines. (Newton's first Law [!?]), but since space and time are not divisible in nature, those straight lines are now called Geodesics, because the shortest distance between two points is now through a "curved space". Planets travel around the sun in ellipses because, given the gravitational effects of the sun on space-time, ellipses are the mathematical "Geodesic", or straight line in curved space-time. It is like an extended conservation law - "everything goes straight. If space curves, then they curve. But they're still going straight". It is elegant. The you boil down the principle of gravitation (and all that hideous Geometry of the Principia) to a specialized case of Occam's Razor. I know it is difficult to envision 4D space-time and ellipses being straight, but there are other ways to visualize by analogy. Imagine Venus and the sun. The principle of this new way of viewing gravitation and straight lines would say that the shortest distance to get to the other side of the sun for the planet is straight through the sun. But as space curves so much more where mass is greater (examine Jeans' example of the lead ball on the cushion and replace it with a bowling ball, see what happens) it takes less distance (4D) to go around. And the closer you get to the mass the more it curves and the harder it gets, so Venus goes faster, conserving the straight (ish) line (remember time is in the 4D continuum too). It is easier to visualize a flat surface, like the cushion and the lead ball, and see the difference in distance if you have to go down to the bottom of where the ball pushes the custion. Around is a shorter distance (assuming that space requires you to stay in contact with the cushion, which is the claim of a curved space-time continuum - you can step outside it). I think general relativity is much more elegant that the poor Lorenz transformations of uniform translation found in the special theory. It preserves straight lines as the motion of choice (redefining "straight"), it more accurately describes nature, and it does away with the problematic idea of "force". (sort of, but more on that at another time) But it is enough to see that a reduction of principles from gravitation down to more a a conservation principle is definite progress in our understanding. But enough of the bigger than man side of physics.........

I was going to write about the small side of physics. But this got way too long. So, I will return to this at a later date (Fuck quantum uncertainty! [again again, for those who know - ed.])