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From: Osher Doctorow on 5 Aug 2010 22:14 From Osher Doctorow The "distraction" of theoretical physics through Germany and Denmark and Austria in the early 1900s through now into Relativity (SR and GR) and its generalizations/modifications and Quantum Theory, which ultimately led to our concepts of "compacted" dimensions and "invisible" dimensions such as Kaluza-Klein, Superstring/Brane/M- Theory, Randall-Sundrum and their modifications, eliminated focus on Dimensional Analysis as a Theory, "exiled" to be applicable to Astrophysics, Mathematical Biology, and Engineering and to "Phenomenological" rather than "Theoretical" Physics mostly (which "Phenomenological" Physics largely explores new problems by giving a "provisional" theory largely based on experiments which then is ultimately replaced by the "Incorporated" (Inc., Ltd., etc.) Theories which work "to the nth decimal place" (Relativity, Quantum Theory, etc.) except that they often can't handle very new discoveries without revolutionizing themselves and even their previous Axioms (recall Einstein's "Principle of Verification"?). Of course, Dimensional Analysis (of Buckingham, Bridgeman, etc.) only postulated a few "Fundamental Dimensions", such as: 1) M (mass), L (length or spatial dimension), T (time) 2) M, L, T as in (1) as well as Theta (temperature) 3) M, L, T, Theta as in (2), as well as (or replacing Theta by) Q (Electrical Charge). If we double each of the 5 dimensions in (3) to account for either "Anti-" or "Oppositely directed" dimensions, which may or may not be the same as their Abelian (commutative) multiplicative inverses like M^(-1), L^(-1), T^(-1), etc., then we already get 10 Fundamental Dimensions arguably, which with one more can be the 10 or 11 dimensions of respectively Superstring or Supersymmetry Theories. Admittedly, there is something "strange" about regarding M^(-1) as a separate Fundamental Dimension from M, but then, the Universe is strange. However, this is only one possibility, and unless I assume it explicitly in some section or subsection, I do not assume it. Now let us summarize Dimensionless Ratios discussed here and involving respectively L, T, M: 4) L1/L2 (two L dimensions as in length of myelinated brain fibers/ earth-moon distance) 5) T1/T2 (this and L1/L2 are in Bode's Law, Dermott's Law, etc. for adjacent planetary vs planetary or planetary vs Star/Sun or planetary vs moon(s) or moon vs moon, etc. systems. 6) M1/M2 (for example Mass of white dwarf - Mass of Earth)/Mass of Earth for Chandrasekhar limit used in Collapse and Supernovae). Of course, we already know from Dimensional Analysis in Engineering, for example, that Lx, Ly, Lz (for x, y, z subscripts) are 3 separate dimensions of space when particular directionality in space is relevant to a problem rather than homogeneity/isometry. And some Physical Theories have come up with two time dimensions (not the majority of such theories, but some). Two mass dimensions explicitly identified seem to have escaped notice mostly. Osher Doctorow Osher Doctorow |