ABSTRACT
We will generalize, by referring to [226], [227], [228], the well known facts about units because Einstein ignored them, which was accepted by Lorentz, Poincaré and others. An amount (the absolute value) g ∈ R+ of a quantity g to be measured,
the goal of the measurement, and the purpose of the quantity usage govern a choice of a unit 1g for the quantity g, unitg = 1g, i.e. g 1g . We use various amounts of the quantity g. We can utilize the quantity g for various purposes. Consequently, we can establish and apply various scales and units for the same quantity g, which we do often. We should distinguish the unit used to measure the quantity g, which is de-
noted by 1(.), from the physical dimension of the quantity g denoted by phdimg and shown between the parentheses [] following the quantity g. The physical dimension of the quantity g is denoted, for example, by G, where G stands for ”quantity g”,
phdim(g) = G, or equivalently, g[G].
