Quantum Drama: From the Bohr-Einstein Debate to the Riddle of Entanglement
It was not a question of whether light should be pictured as waves or particles, or atoms as solar systems, but of whether the microworld could be pictured at all.
The famous debate between Albert Einstein and Niels Bohr reached beyond quantum physics to the deepest foundations of science. Faced with the ever more perplexing ‘irrationalities’ of quantum theory as it was forged during the first half of the twentieth century, Bohr, Einstein, and their followers fell into two broadly opposed camps. Bohr’s approach of ‘complementarity’ accommodated the apparent absurdities of the microworld, extending the language of classical physics but treating its continued use as ‘symbolic'; although he could not quite capture it in language, he asserted that it was mathematically coherent and complete. Einstein could not accept what he called Bohr’s ‘tranquilizing philosophy’, which admitted probabilities rather than causal certainties into the foundations of the theory. He insisted that physicists look more deeply for the causes of entanglement and spooky actions at a distance.
They disagreed respectfully and profoundly over the degree of freedom that physicists have to define the purposes and principles of their science. Their discussion reached stasis in the mid-1930s with the apparent victory of Bohr and the shift of interest to nuclear and particle physics. But their arguments continued to reverberate and a few physicists who entered the field a decade or two after World War II invented testable consequences of the theory that confirmed its radical strangeness.
This erudite and carefully crafted telling by Jim Baggott and John Heilbron may prove to be the definitive account of the Einstein-Bohr debate and its legacy. It vividly captures the personalities and interactions of a remarkable cast of characters, relates the quantum drama to social and political developments, and offers accessible explanations of theory and experiment. Despite the depth and importance of the subject, the story is told with a sensitivity and wit that can surprise the reader into laughter.
- Oxford University Press (25 April 2024)