Comment Re:Logical positivism to the rescue... (Score 5, Informative) 798
Your reasoning is subtly but fundamentally flawed. Yet as with all subtlties, pinpointing the exact nature of the flaw is difficult without having a back-and-forth conversation.
You are right on target with respect to Ohm's law and Hooke's law -- but quite off base with your general assertion. The deep laws of physics *are* eerily symmetric, independent of our need to describe them so.
For example, the inverse-square law of gravity or electromagnetism can be derived as a consequence of living in a 3-dimensional universe. (Integrate your favorite conserved quantity over concentric spherical surfaces and you get something that must "fan out" as 1/r^2). Nothing very suprising there. Nevertheless the deeper into exploration of physical laws you get, the more surprising interconnections pop up independent of our need to observe them.
Your assertion that "momentum" is simply a convenient and observed quantity is both false and misleading. "Momentum" is a fundamental quantity that relates directly and
Thus, it is misleading to imply that our physical laws are simple and elegant because we have simple and elegant requirements to describe the universe. An accurate description of the universe need not be simple -- and often it is not. For instance, I understand (although lack the mathematical sophistication to prove) that the electron spin g-factor has a theoretical value of exactly 2. Yet it is observed to be approximately 2.00232 and is one of the most precisely measured physical constants. So it is not always simple truth and beauty. Which makes it all the more surprising when the simplicity is there nevertheless.
And while it is true that the inverse-square law breaks down at relativistic energies, even that corrective factor of "gamma" remains mathematically simple, and in fact geometrically constructable via a pythagorean triangle analysis of a certain thought-experiment.
My point is that the easy examples are easily explained away by laymen, yet the surprisingly simple nature of the fundamental laws of the universe continue to pop up where you wouldn't expect. That is why expert scientists, true geniuses, of the sort that don't come along every day, routinely make comments about the "beauty" of physics. They have a deep understanding and "feeling" about the way the universe fits together that isn't captured by your example about momentum.