Here’s what Gary Zukav has to say about superposition (p. 285) in The Dancing Wu Li Masters: “A ‘superposition’ is one thing (or more) imposed on another. A double exposure, the bane of careless photographers, is the superposition of one photograph on another.”
Well, some people intentionally make double exposures for the fun of it, but either way, intentional or not, it’s a good example of classical superposition. Zukav next discusses quantum superposition, which he calls coherent superposition: “A coherent superposition, however, is not simply the superposition of one thing on another. A coherent superposition is a thing-in-itself which is as distinct from its components as its components are from each other.”
Now Zukav uses the example of polarized light—the same example I was talking about earlier: two polarizers, one “vertical” and one “horizontal”, allow no light to pass through, but when a third polarizer oriented at a 45 degree angle is placed in between these, light is able to pass through this triple combo of polarizers. How? Why?
Zukav says, referring to the 45° polarizer in the middle as producing diagonally polarized light: “Diagonally polarized light is a coherent superposition of horizontally polarized light and vertically polarized light. Quantum physics abounds with coherent superpositions. In fact, coherent super-positions are at the heart of the mathematics of quantum mechanics. Wave functions are coherent superpositions.” Woowee, wave functions! Now we’re getting somewhere! "Coherent" comes up again also.
You may remember this discussion started with my interest in a new book I received in the mail earlier this year, called Introduction to the Theory of Coherence and Polarization of Light, by Emil Wolf. I would not be interested at all except I'm trying to make a discovery. Back in the mid-seventies, before I had any advanced physics training, after reading a World Book encyclopedia article about some of the mysteries of quantum mechanics (I was in the back bedroom at my grandmother's house in Little Rock), I fell asleep and woke up with an idea: "diffuse retardations." I wrote down those words even though they meant nothing to me at the time, but I later learned that a retarder in optics is a material like a birefringent crystal that changes the polarization of light passing through it. The "diffuse" part is still mysterious and is something I'm still working on, but seems related to the 1980s idea of "decoherence" promoted by James Hartle and others. Thus my interest in writing this--as a means of searching and researching--regardless of whether anyone else is reading it.
You may remember this discussion started with my interest in a new book I received in the mail earlier this year, called Introduction to the Theory of Coherence and Polarization of Light, by Emil Wolf. I would not be interested at all except I'm trying to make a discovery. Back in the mid-seventies, before I had any advanced physics training, after reading a World Book encyclopedia article about some of the mysteries of quantum mechanics (I was in the back bedroom at my grandmother's house in Little Rock), I fell asleep and woke up with an idea: "diffuse retardations." I wrote down those words even though they meant nothing to me at the time, but I later learned that a retarder in optics is a material like a birefringent crystal that changes the polarization of light passing through it. The "diffuse" part is still mysterious and is something I'm still working on, but seems related to the 1980s idea of "decoherence" promoted by James Hartle and others. Thus my interest in writing this--as a means of searching and researching--regardless of whether anyone else is reading it.
One more quote from Gary Zukav, then we will move on to Gordon Baym, J. J. Sakurai, and Arthur Fine. Zukav mentions the “observed system,” which of course implies an observer. An “observation” or measurement. In the Schrodinger’s cat experiment is what causes the cat to go from coherent superposition of “alive and dead” to either alive or dead. The question for those who don’t simply dismiss it as a meaningless question is: what in this case is the observation? Now, go Gary:
“Every quantum mechanical experiment has an observed system. Every observed system has an associated wave function. The wave function of a particular observed system (like a photon) is the coherent superposition of all the possible results of an interaction between the observed system and a measuring system (like a photographic plate). The development in time of this coherent superposition of possibilities is described by Schrödinger’s wave equation. Using this equation, we can calculate the form of this thing–in-itself, this coherent superposition of possibilities which we call a wave function, for any given time. Having done that, we then can calculate the probability of each possibility contained in the wave function at that particular time. … In a nutshell, that is the mathematics of quantum physics.”
