Re: Radians, dimensions, & explanations

["Rauber, Joel Phys" <RAUBERJ@MG.SDSTATE.EDU>]

Rauber, Joel Phys wrote:
> > One can use this, { (1) and (2) above }, as an opportunity to distinguish
> > between *units* and *physical dimensions*.  E.g. *length* is a physical
> > dimension, the SI unit for length is *meters*.  If you make this
distinction
> > then the *radian* is not a psuedo-unit, but is an actual honest-to-gosh
> > unit; it does happen to be a dimensionless unit!
>
> Not if you wish to maintain the convenient rule that units combine
> algebraically.

Point well taken!!  I would add that the conventional approach is not to
have that convenient rule, the *radian* being an obvious exception; but
rather the rule that *physical dimensions* combine algebraically; with no
exceptions that I'm aware of.

Joel Rauber