From the early days of quantum mechanics, Albert Einstein did not hide his dissatisfaction with the statistical nature of quantum mechanics and the fact that certain observations such as location and time cannot be simultaneously measured with any accuracy. By the mid 1930s, Einstein had accepted quantum mechanics as a consistent theory for the statistics of the behavior of atoms. Eventually the applications would include transistors, lasers, a new chemistry, and more. Yet Einstein could not accept quantum mechanics as a complete theory, for its mathematics did not describe individual events. Einstein felt that a more basic theory, one that could completely describe how each individual atom behaved, might yet be found. By following the approach of his own general theory of relativity, he hoped to dig deeper than quantum mechanics. The search for a deeper theory was to occupy much of the rest of his life.