This is phenomenally interesting to me because that very question led me to understand a lot more about the nature of units themselves. In particular, EM practi

This is phenomenally interesting to me because that very question led me to understand a lot more about the nature of units themselves. In particular, EM practitioners often use "Gaussian units" that name the math much cleaner (factors of 4pi appear and then disappear, instead of carrying around ε0 everywhere), but they have the weird side effect of perverting SI units. For example, in Gaussian units the standard unit of charge, the statcoulomb, has dimensions involving length to the 1/2 power. I think that has rather interesting implications on the nature of length; it seemd to me that the dimensions we take for granted might not be as fundamental as we think.