The Bohr/Einstein debates were a series of public disputes about quantum mechanics between Albert Einstein and Niels Bohr, who were two of its founders. Their debates are remembered because of their importance to the philosophy of science. An account of them has been written by Bohr in an article titled "Discussions with Einstein on Epistemological Problems in Atomic Physics". Despite their differences of opinion regarding quantum mechanics, Bohr and Einstein had a mutual admiration that was to last the rest of their lives. (Wikipedia) Einstein’s theories on quantum mechanics came about when Max born stated that mechanics was to be understood as a probability without any causal explanation. Einstein was displeased and sent a letter saying, “"I, at any rate, am convinced that He [God] does not throw dice." I think Einstein meant that things don’t happen for any apparent reason and instead of assuming something happened we should figure it out for ourselves.
Einstein uses the double-slit light experiment to prove Born’s theory incorrect. The double-slit light experiment is a “demonstration in which matter and energy can display characteristics of waves and particles as well as demonstrating the fundamentally probabilistic nature of quantum mechanical phenomena.” The experiment conducted to produce this theory involved a coherent light source such as a laser beam that illuminates a thin plate pierced by two parallel slits, and the light passing through the slits is observed on a screen behind the plate. The wave nature of light causes the light waves passing through the two slits to interfere, producing bright and dark bands on the screen, as result that would not be expected if light consisted strictly of particles. However, on the screen, the light is always found to be absorbed as though it were composed of discrete particles or photons. This establishes the principle known as wave–particle duality. Additionally, the detection of individual photons is observed to be inherently probabilistic, which is inexplicable using classical mechanics. (Wikipedia)
When Bohr came along and tried Einstein’s experiment he found that Einstein had made a mistake. Einstein considers a box called Einstein's box containing electromagnetic radiation and a clock which controls the opening of a shutter which covers a hole made in one of the walls of the box. . Einstein's box was supposed to prove the violation of the indeterminacy relation between time and energy. Bohr showed that, in order for Einstein's experiment to work, the box would have to be suspended on a spring in the middle of a gravitational field. In order to obtain a measurement of weight, a pointer would have to be attached to the box which corresponds with the index on a scale. After the release of a photon, weights could be added to the box to restore it to its original position and this would allow us to determine the weight. But in order to return the box to its original position, the box would have to be measured. The inevitable uncertainty of the position of the box translates into an uncertainty in the position of the pointer, of the determination of weight, and of energy.
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