|Linda, in Cape May, NJ|
Linda and I are taking a week of vacation in Cape May, New Jersey. We do a lot of reading in places like this. This morning I pulled up and read an essay by Princeton's Hans Halvorson on quantum intederminacy - "What Does Mechanics Suggest About Our Perceptions of Reality?" It's very good for those of us who are not physicists but want to understand big ideas. (I make posts like this as much for my own reference as for others.)
"Quantum indeterminacy is the unavoidable fact that not all quantities can simultaneously have determinate values. For example, if an electron has a location, then it simply has no speed – it is neither at rest, nor is it moving slowly, nor is it moving quickly. There simply is no fact of the matter about its state of motion. Similarly, if an electron is in a definite state of motion, then it’s not in any particular place – not here, nor there, nor anywhere."
The radicalness of this is not that if you know the position of the electron then you don't know whether or not it is moving. Quantum indeterminacy holds that if and electron has a position then it is not moving. And, conversely, if and electron is moving then it has no position. Halvorson comments: "What could this possibly mean? No one is quite sure."
Halvorson (and others) reject Heisenberg's theory of subjective idealism; viz., that "the act of “looking” caused the electron to take on a definite state of motion, or a definite position." Halvorson gives other proposed solutions to the quantum indeterminacy dilemma.