When Heisenberg first unveiled his famous uncertainty relations, they were often misunderstood. Many experimental physicists actually took them as an affront to their skill and saw this as a challenge to be overcome. How dare the theorist Heisenberg, who has probably never been in a lab himself, tell them how precisely they can make their measurements!
With time, however, and a lot of explaining on Heisenberg’s part, it became clear that the uncertainty relations had nothing to do with how skilled or clumsy an experimenter was. They represented not just a limit on the quality of measurements, but a fundamental limit to what can possibly be known.c
QUANTUM LEAP
Soon after Heisenberg moved to Copenhagen, he and Bohr had many heated exchanges about the nature of wave-particle duality. Then, in 1927, Bohr went on an extended skiing holiday. During their separation, Bohr developed an interpretation of quantum physics rooted in duality, while Heisenberg came up with his uncertainty relations. Their debates continued after Bohr’s return, and eventually Wolfgang Pauli was summoned to Copenhagen to mediate. The result was a compromise viewpoint that Heisenberg referred to as the “Copenhagen spirit,” which eventually became known as the Copenhagen interpretation.
Hidden behind his seemingly simple mathematical formula (Δx × Δp > h) was the baffling notion of wave-particle duality. The Heisenberg uncertainty relation indicates that we cannot simultaneously measure the position and momentum of an electron with perfect precision. This implies that we can’t devise an experiment that displays both particle and wave properties of an electron at the same time. This isn’t because no experimenter is clever or skilled enough to do so. Rather, the wave and particle characteristics of an electron simply do not simultaneously exist.
Leave a Reply