IJ ellipse. (More EE than anyone cares to know)

[Brian D. McCary]

> Date: Fri, 22 Mar 1996 12:00:31 -0800 (PST)
> From: Jeffrey Reid <jgreid at u.washington.edu>
> 
> > > And I have no idea what that guy meant
> > > by saying that if you graph two asynchronously blinking pulses you
> > > get an ellipse.
> >
> If I remeber correctly (it's been a long time since I've used one...) on
> an oscilloscope if you have two asynchronously varying inputs and you set
> the scope in the proper mode it will graph out an ellipse.  The degree of
> eccentricity of the ellipse is a measure of the phase difference between
> the signals.  (i.e. signals in phase give a circle).
 
Close enough.  Two asynchronously varying sinusoidal inputs yield what
is called a Lissajous pattern, which appears to rotate.  If their
frequencies are within an octave of each other, you get an ellips with
an eccentricity which varies with time, going (as I recall) from a 
diagonal line to an ellipse back to a line.  If the two voltages are the
same, the ellipse momentarily approximates a circle.

If the two signals have the exact same frequency, you get a static ellipse.
Needless to say, in this case, they are not asynchronous.  If the 
voltages and the phases are the same, the ellipse degenerates into a
circle.

Not having read IJ, and not knowing the exact pulse trains he is thinking of,
I would venture to guess that two blinking pulses on an oscilloscope 
would yield a box with faint diagnonals.  Wallace might have had something
differant in mind, and simply not communicated it well.  Or, he might have
overreached his understanding of the technical details.  This is the 
kind of technical detail mistake which seems rare in Pynchon.  Do you 
suppose Wallace reads Scientific American avidly?  For that matter, 
given _Vineland_, is TRP still subscribing, or is he concentrating on
other things?

Brian McCary