We can do a lot more than simply say " I don't know". We can assign a level of probability to a phenomenon, based upon empirical fact, plausible hypothesis, and observable and reliably reproducible event.
We can conclude that gravity is as described. Therefore the ability of someone to "levitate" ie defy gravity by means of an as yet undetermined force, is extremely improbable. In fact, the chances that it could happen are so infinitesimally small that we can assign a value to that proposition, which is so close to zero as to be zero, for all intents and purposes.
Thats not an example of a closed mind - thats a scientific, objective and dispassionate analysis of the evidence, which leads us to a conclusion. Reject that premise and you reject the whole basis of rational thinking.
This same method and same mechanism is used to assign a probability to gods existence, and much the same conclusion is arrived at- the probability that a personal god, omnipotent, omniscient, responsive to prayer etctetc - the type of god described by the major abrahamic religions - is so infinitesimally small as to be, to all intents and purposes zero.
Not a closed mind - an examination of the evidence and a rational conclusion.
We may yet find some as yet unsuspected interaction between electromagnetism and wires, or bits of stick, or quartz. Naomi offered a link to a Swedish guy who speculated about such things. But thats all it was- speculation. I would like to see him follow up on that, do some experimentation - show us how the piezo-electric effect might in fact be the answer for dowsing. That would be good, and exciting, and interesting. But he wrote the paper some while ago now, and has not published any data to support his speculation, so whats the reasonable conclusion to be drawn?
Yes, we are basing such conclusions on science as we know it today. So yes, it is possible that some new science will come along, or some new force might reveal itself that can explain all of these previously mystical or paranormal issues - but we no longer have big "here be dragons" gaps in our understanding of the world and the cosmos that would allow for such paradigm shifts, in my opinion. So again, a small possibility - higher than, say, the likelihood of a personal god, but not by very much more.