(InterestingEngineering) Few scientists have made as much impact on the modern world as Niels Bohr. In honor of the 56th anniversary of his passing, this article delves into his pioneering work on Quantum Mechanics and Complementarity. Bohr’s unique contribution to the philosophy of physics was the complete upending of the classical model of physics that had existed since Newton: electrons that could exist in several places at once, they could be a particle one minute and act like a wave the next, and that until it is observed or measured, a particle could be in any number of mutually exclusive states simultaneously. Within a decade of his discovery of the structure of the atom, Bohr and his followers had discovered a whole new form of physics: Quantum Mechanics.
Bohr’s insight into the prevailing model of the atom would lay the groundwork for much of the technological advancements of the 20th century. He demonstrated that around each atomic nucleus, there were several levels of concentric shells filled with electrons and showed that the change of an atom’s state was due to electrons moving between shells as they absorbed or radiated energy.