[BC] need a NON-technical explanation

[Harold Hallikainen]

> cycles and kilocycles. In fact, the "father" of antenna theory, Fredrick
> Terman, wrote a book, Antennas, a copy of which I have, with a whole
> chapter devoted to using "turns" instead of cycles and two-PI-radians,
> etc., because the calculations were much simplified. That was written in
> the '30s, well before Hz was forced. His "Radio Engineering," circa 1932
> Richard B. Johnson

We STILL do a lot of stuff in radians per second. We use lower case omega
(looks like a w) to represent frequency in radians per second. For
example, the reactance of an inductor is

X = 2*pi*f*L

or

X = w*L

So, the 2 pi everywhere is just changing Hz or cycles per second to
radians per second. And, "radians" is actually a "unitless unit" since
it's length divided by length (circumference of the arc divided by the
radius of the arc).

I'm currently doing a lot of stuff with mW/sr or milliwatts per steradian.
It works out a lot more nicely than using degrees...

One final comment: I never understood why we have MKS and CGS unit
systems. Why not just use the basic units? Not meter, kilogram, second,
but meter, gram, second. Also, not centimeter, gram, second. We should
only have to apply the metric prefix once to scale our final result. I
don't think we should have metric prefixes used in defining other units. I
think this was probably done to get a basic unit within "practical" range.
But, for the longest time, we've used the "impractical" unit of Farad
without a problem (of course, now we do have one or two Farad capacitors,
but for the longest time we had uF, pF, or in the old days, uuF or mmF. I
recently found a signal generator whose dial is calibrated in
kilo-megacycles).

Harold