Should we believe the physicists?
DOI link for Should we believe the physicists?
Should we believe the physicists? book
Debates over quantum theory have sometimes strongly encouraged these doubts about external reality. A central plank in the theory, the famous Heisenberg uncertainty principle, says that the position and speed of a particle cannot be precisely measured at the same time. Initially, this was thought to be a consequence of the smallness of physical particles: any observation of position would disturb them and blur their speeds. This interpretation is now known to be false. Instead, there is a consensus now that particles do not have both a position and a speed at the same time. That is, when a particle has a precise speed, it has no position in space. Since it is hard to imagine what a particle without a position would be, some draw the conclusion that only observed properties exist. There is no hard little particle moving about independently of our observations. This interpretation was pondered by Einstein in the above quote, and has been advanced by physicists like Bernard d’Espagnat, John Wheeler and others. John Bell’s result, discussed earlier, is sometimes interpreted as a proof of these strange views: it suggests to some that properties observed in the “wigglejiggle” EPR experiments could not have existed prior to their being observed. That is, particles have neither a position nor a speed until observation somehow materializes them.