Re: Radians, dimensions, & explanations

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

Ludwik Kowalski wrote:
> James McLean wrote that the concept of the angle is special in
> terms of being intrinsically dimentionless. I do not think so.
Perhaps the messages got scrabled?  I just said that none of your examples
were convincing to me as being *unitless*.  Consider:
25 degrees C
   = 0.25 (of the temp difference between boiling and freezing)
How is this different from
   = 25 (of 0.01 times the temp difference between boiling and freezing)
which is precisely what "25 degrees" C means?

> Unit of length was defined as a distance between two lines on a
> chosen stick.  ...
Now that sounds like you are talking about *units* again, rather than
dimensions.  Come to think of it, I'm not sure how I would define
'dimension'.  Jack (I think?) gave a fine description of how one might
decide on different base dimensions, but I don't think we've seen a
definition of 'dimension' itself.  Any takers?

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