The challenge of measuring motion and position at the same time is illustrated among the characters in the scene, some crisp, some blurred. The same challenge led Einstein to a now famous thought experiment: Link to paper.
He wanted to expose, as he saw it, an absurdity of quantum mechanics. In measuring speed and position of space-separated but quantum entangled particles, the theory seemed to allow faster than light communication, which was against his special theory of relativity. Although his view of quantum mechanics turned out to be incorrect, his genius was in finding questions that get to the heart of the matter. The experimental tests of his thought experiment were key steps in understanding entanglement, which underpin quantum computers.
