From Wikipedia, the free encyclopedia
Jump to: navigation, search

I am, to all intents and purposes, retired as a WP editor; I no longer maintain mainspace articles on my watchlist for long, and my edits rarely relate to content – especially when I feel that they might be at all contentious. I enjoyed editing WP immensely and learned a lot from it, but have become enervated.[1]



My preferred set of units:[2] SI[3] – (with reservations[4]), and IEC binary prefixes.

My preferred set of natural units could be termed rationalized Planck units defined by base units equal to products of powers of the constants c0[5], ħ, ε0, kB, G0 = −1/(4πG)[6], Np, rad, nat.[7]


I'll generally prefer a presentation that makes an underlying symmetry salient. For example, I prefer Maxwell's equations expressed in terms of E and H rather than E and B – to emphasise the symmetry of E–M duality. Also manifestly coordinate-free formulations in physics.


Exclusion of trivial cases to avoid awkward phrasing of theorems at the expense of mathematical regularity is something that I find ugly. Every class of mathematical object should be defined such that a homomorphism onto the trivial terminal object is well-defined. First-order logic should not axiomatically exclude the empty universe of discourse. The axiom 0 ≠ 1 typically used in defining fields is one example of such an exclusion.





  1. ^ I have tired of the not-so-charitable approach of several editors, to the point that I now say "Why bother?". Maybe I'm just getting old.
  2. ^ One should start with quantities (such as in the ISQ). These would include a locally orthogonal set of four separate geometric dimensions (time, x-distance, y-distance, z-distance), plane angle, solid angle and higher angles (as well as hyperbolic angles), speed, mass, energy, information entropy, electric charge, magnetic charge, colour charge (triple), temperature, and many more.
  3. ^ Specifically, the proposed redefinition of SI.
  4. ^ The use of the prefixed unit kg is awkward, and luminous intensity does not "belong". Treating nat, Np, and rad as dimensional constants helps with clearer thinking; these are fundamentally logarithmic quantities and for this reason inherently distinct from standard dimensionless quantities. The Np may be considered as the unit of hyperbolic angle.
  5. ^ An interesting choice would be to use the constant c02 rather than c0, and in normalized units to put 1 = −c02. This does not imply that the imaginary unit is used but only that a three-dimensional velocity vector squares to a negative value. This embodies the inescapable result of special relativity that because the square of a timelike vector delta has the opposite sign of the square of a spacelike vector delta, the ratio of the two squares is negative. This does not in general change the standard form of equations in natural units, but rather how an equation is expressed in SI units.
  6. ^ The unusual choice of normalization for a gravitational constant results from two considerations: that the reference direction for force be consistent (independent of the type of force, for example when matched with Coulomb's law), and that the equations be rationalized. Forgive the pun, but I consider this to be the only rational choice, especially when considering other symmetries and numbers of dimensions.
  7. ^ Derived units would equal the constants μ0 = 1/(ε0c02), Z02 = μ0/ε0, q02 = c0ε0ħ. The electromagnetic coupling constant would be e = 4παq0 ≃ 0.30282212⋅q0.