To summarize: a measurement need not give enough information to convert a wavefunction into an impulse (point) function. Not all measurements give you point inf

To summarize: a measurement need not give enough information to convert a wavefunction into an impulse (point) function. Not all measurements give you point information. A measurement could provide enough information to constrain the wavefunction to a more restricted (knowledgeable) form (lower entropy if you use integrate over the wavefunction -- that is Integral(-P(x)*Log(P(x)))) This is especially the case with entanglement. By measuring one entangled observable, we often increase our knowledge but not absolutely like in the naive explanations that have you believe it is always an entangled pair of spin up and spin down.. All measurement does is reduce uncertainty/entropy of the wavefunction. The strange part is that one can actually undo this restriction by erasing any traces of the measurement. See the Delayed choice quantum eraser experiment. Collapse doesn't really exist.. It's more like expressions that can be reduced, appear reduced, until they cannot be reduced..thus they appear expanded. Imo, entanglement is evidence that all interactions are lazily computed and are copy-on-read or lisp expressions that gradually become larger as interactions continue, and are beta or alpha reduced when possible.