[sdiy] "spiral" waveforms - what about them?

[nN AAt e e]

> The term "spiral", apparently, refers to the 3D nature of the
> graphical representation of these waveforms, actually, more
> than one waveform.
...
> Or am I:
> 1) over simplifying.
> 2) not seeing what utter BS this is.

i would have to say closer to #2... im not that great at math and i haven't
taken any physics yet, so as far as i can tell... it's sort of like wave
terrain synthesis [though projected sideways instead of on one plane]...
with two sine waves of opposite phase combining with each other, and i guess
the actual spiraling part is kind of made up...

now who's over simplifying it? :P ... acually i guess im not... i think we
have been looking at this backwards, starting witht he waveforms... but it
makes more sense the other way around:

"If we stretch a helical spring parallel to the wall and floor of a room and
project its (stationary) shadow on the wall, we see a sine wave. If, without
moving the spring, we project its shadow on the floor, we see a second sine
wave which is out of phase with the one on the wall by ±90°. While this is
an idealized picture, if we accept the spring shadow on the wall as the
function cos(t) and its projection on the floor as sin(t), then the sinusoid
on the wall is said to be in quadrature with the one on the floor. Figure
3.1 [ http://staff.washington.edu/bradleyb/spiralsynth/fig3.1.gif ] is an
illustration of two such waveforms, projected from a single spiral. In the
language of signal processing, we are talking about an analytic signal where
the real part is projected on the "wall" (labeled Re) and the imaginary part
is projected on the "floor" (labeled Im). "

from: http://staff.washington.edu/bradleyb/spiralsynth/spiral.html

- nate