Re: Radians, dimensions, & explanations

[James Mclean <jmclean@CHEM.UCSD.EDU>]

Ludwik Kowalski wrote:
> Every physical quantity can be expressed quantitatively in the
> dimentionless form, if we want.

It seems to me that all of these examples have units:

25 degrees C =
   0.25 (one quarter of the temp difference between boiling and freezing)
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
48 volts = four times as much as in my fully loaded car battery"
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Or a charge of seven electrons
                     (unit = charge of 1 electron)
energy of 10, meaning ten times as much as that of one galon of water rased
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     to an elevation of one furlong
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The fact that the thing to which you compare all else is "natural" does not
remove its status as a unit.

--
--James McLean
jmclean@chem.ucsd.edu
post doc
UC San Diego, Chemistry