Quote (AEtheric @ Nov 21 2010 11:19pm)
The nature of the wavefunction need to be addressed. It is time for the physical rather than the mathematical nature of the wavefunction to be determined.
Unless, of course, if two electrons interacting constitutes a "measurement" and the wavefunction collapses just from that. For example, the solution to the Schroedinger's Cat paradox is that the Geiger Counter detecting radiation (or not) constitutes the measurement which collapses the Cat's wavefunction.
Here's what David Griffiths concludes his Quantum Mechanics textbook with. I added the bold toward the end to emphasize what is probably the most relevant sentence, but really the whole thing is cool enough to be repeated.
Quote
In this book, I have tried to tell a consistent and coherent story: The wave function (Psi) represents the state of a particle (or system); particles do not in general possess specific dynamical properties (position, momentum, energy, angular momentum,etc.) until an act of measurement intervenes; the probability of getting a particular value in any given experiment is determined by the statistical interpretation of Psi; upon measurement the wave function collapses, so that the immediately repeated measurement is certain to yield the same result. There are other possible interpretations -- nonlocal hidden variable theories, the "many worlds" picture, "consistent histories," ensemble models, and others -- but I believe this one is conceptually the simplest, and certainly it is the one shared by most physicists today. It has stood the test of time, and emerged unscathed from every experimental challenge. But I cannot believe this is the end of the story; at the very least, we have much to learn about the nature of measurement and the mechanism of collapse. And it is entirely possible that future generations will look back, from the vantage point of a more sophisticated theory, and wonder how we could have been so gullible.