RussellMc wrote:

>>> You mean like "to get the length of your dipole antenna, divide 468 by
>>> the frequency"? (which gives you the length in feet, of course.)
>=20
>> ... if you use the right unit for frequency, of course :)
>=20
>> Exactly this. I hate it; it doesn't convey understanding as more
>> sensible formulas tend to do, and I just can't remember such stuff.
>=20
> I too like my formulae to make sense. This one does once you remove
> the rubbish and convert to 'propr units' [tm].

This is exactly the thing. All these "magic formulas" have some sense of
this sort in them, but it's buried, and the "proper units" (plus of
course some understanding of what's going on) help bring it out -- and
the result of this bringing out is usually much more helpful. Not for
any given task, but for life... :)

The SI-like systems basically reduce the "magic numbers" to a few basic
constants (speed of light, charge of an electron, etc.) It's still more
than would be nice, but better than otherwise.

Gerhard
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.