Every time I read Mondaugen's Law, I see a different shade of meaning in it. On some level it seems like a complicated phrasing of common sense -- that in order not to be flighty, one must bear in mind the predecessors to, and repercussions of, one's actions. The act of phrasing it as a scientific theorem makes me step back and examine the common-sense meaning.
My first impulse is to rebel against it -- surely the narrower the temporal bandwidth, the more focussed one is in the present moment, the "denser" one's personality will be -- here I am extrapolating my understanding of the word "dense" from its use in describing physical objects.
But at the same time there is a voice in my head saying I understand the point Pynchon is getting at here even if I can't put the words together in a sensible way. The notion of describing "personality" as a wave form seems like it could potentially be extremely useful, though my grounding in physics is not sufficient for me to understand exactly how.