![]() In contrast, in 1957 the physicist Hugh Everett asserted that wave function collapse is just an illusion and that in fact all outcomes are realized in a near-infinite number of branching universes - what physicists now call “ many worlds.” ![]() The Danish physicist Niels Bohr, in his so-called Copenhagen interpretation, simply pronounced the issue out of bounds, saying that physicists just had to accept a fundamental distinction between the quantum and classical regimes. Einstein famously likened it to God playing dice to decide what becomes “real” - what we actually observe in our classical world. But it seemed (and continues to seem) to some researchers to be an unsatisfactory sleight of hand. Quantum mechanics itself doesn’t appear to predict the collapse, which has to be manually added to the calculations.Īs an ad hoc mathematical trick, it works well enough. The process is essentially random but biased by the probabilities it encodes. What determines a specific observation? In 1932, the mathematical physicist John von Neumann proposed that, when a measurement is made, the wave function is “collapsed” into one of the possible outcomes. But there’s no way of knowing what the outcome of any single measurement will be - quantum mechanics offers only probabilities. If many measurements are made on such objects when they’re prepared in an identical manner, the wave function always correctly predicts the statistical distribution of outcomes. Rather, it is a “probability wave,” which allows us to predict the various possible outcomes of measurements made on the object, and the chance of observing any one of them in a given experiment. As the name implies, a wave function describes a kind of wave - but not a physical one. In 1926 Erwin Schrödinger asserted that a quantum object is described by a mathematical entity called a wave function, which encapsulates all that can be said about the object and its properties. Physical collapse models aim to resolve a central dilemma of conventional quantum theory. But while “it is always possible to rescue any model,” said Sandro Donadi, a theoretical physicist at the National Institute for Nuclear Physics (INFN) in Trieste, Italy, who led one of the experiments, he doubts that “the community will keep modifying the models, since there will not be too much to learn by doing that.” The noose seems to be tightening on this attempt to resolve the biggest mystery of quantum theory. Some researchers believe that the models could yet be modified to escape the constraints placed on them by the experiments’ null results. ![]() It’s still too early to say definitively that physical collapse does not occur. Recent experiments have mobilized the extreme sensitivity of particle physics instruments to test the idea that the “collapse” of quantum possibilities into a single classical reality is not just a mathematical convenience but a real physical process - an idea called “physical collapse.” The experiments find no evidence of the effects predicted by at least the simplest varieties of these collapse models. Possible explanations for how observations of the world yield definite, “classical” results, drawing on different interpretations of what quantum mechanics means, have only multiplied over those hundred or so years.īut now we may be ready to eliminate at least one set of proposals. How does objective reality emerge from the palette of possibilities supplied by quantum mechanics? That question - the deepest and most vexed issue posed by the theory - is still the subject of arguments a century old.
0 Comments
Leave a Reply. |