The quantum mechanical wave function for a system of n particles is a function on a 3n-dimensional space. If these pilot waves are something real, where do they live, in ordinary 3-space or in 3n-space? How is spin handled? When a measurement is made on one of two separated entangled particles, does the pilot wave of the other particle change instantaneously, faster than the speed of light? The Bohmians need to answer these questions if they hope to be taken seriously. While these fluid dynamics experiments are nice, those waves are real waves that can be measured. There is no way to measure a wave function. If the Bohmians wish to reify (make real) the wave function, they should either show us how to measure it, or be very clever in explaining why it can't be measured. The true significance, to me at least, of the Einstein-Podolsky-Rosen paper is that it demonstrates that the wave function cannot be reified, not without violating causality. One should separate the physical part from the interpretive part. The physical part is what can be experimentally measured, and the standard theory does that job admirably. The interpretive part fills the gap in our intuition, our lack of understanding why physics should be quantum mechanical, our dissatisfaction with its foundations. It's not like, once you see F=ma, you say, "but of course, it could not be any other way." Interpretations are personal opinions, as long as their predictions agree with experiment. Most physicists go with the Copenhagen interpretation since it appears to be the least problematical. This is the interpretation which posits that the wave function is a probability amplitude, possessing the same kind of reality as classical probability. -- Gene