Free Einstein and the Quantum by A. Douglas Stone Page B

hundred times as much about the quantum problems as I have about Relativity Theory.”
    It is crucial to understand that while relativity theory is an important part of modern physics, for most of us quantum mechanics is the theory of everything. Quantum mechanics explains the periodic table of the elements, the nuclear reactions that power the sun, and the greenhouse effect that leads to global warming. The quantum theory of radiation and electrical conduction underlies all of modern information technology. Moreover, quantum mechanics has already subsumed part of relativity theory (the “special theory”). The goal of modern string theorists and their well-publicized “theory of everything” is to have quantum mechanics gobble up all of general relativity as well. Since quantum mechanics is the big kahuna, it behooves us toappreciate the role of Einstein in the “other” revolution of twentieth-century physics, the quantum one.
    To understand Einstein’s seminal role in this revolution, it is necessary to understand what had come before him. In this subject he had exactly one predecessor, the eminent German physicist Max Planck, of whom we will learn much below. Planck was the first major figure to recognize Einstein’s seminal 1905 work on relativity theory, and he became Einstein’s greatest champion in the world of science and one of his closest personal friends. But Einstein’s work in the quantum theory—that was another matter. Sometimes it is easier to recognize the genius that doesn’t paint in your own style. Planck had not worked on the problems that were solved by relativity theory, but he had worked on the quantum theory. In fact Planck, not Einstein, is universally regarded as its originator, based on his work on heat radiation in December 1900. Planck, a truly admirable man of science, indeed achieved something of incalculable significance as the new century began. But what it was, and what it meant, are not as clear as the textbooks maintain.
    At the moment that Planck was making his historic advance the young Einstein, just graduated from the Zurich Polytechnic, was coming to a bitter realization: he was not wanted in the world of academic physics. Already engaged to his classmate Mileva Maric, as his travails, both practical and scientific, multiplied, he maintained a bold self-confidence. This was exemplified by a humorous nickname he chose for himself in his letters to Mileva: the “Valiant Swabian,” after the swashbuckling crusader-knight invented by the Swabian romantic poet Ludwig Uhland. Einstein had just submitted his first research paper to the Annalen der Physik ; it was on liquid interfaces and proposed a novel (but simplistic) picture of the forces between atoms. This would signify the beginning of his lifelong quest to understand the laws of physics on the atomic scale.

CHAPTER 8
    THOSE FABULOUS MOLECULES
    One of the great open questions in the history of science is how Einstein came to the core idea of his paradigm-shifting paper of 1905. No, not his paper on special relativity or his paper proposing the famous equation E = mc 2 . Einstein was asked over and over again how he had developed the key insights leading to the special and general theories of relativity, and he answered with various charming anecdotes that have become part of his legend. As far as we know, he never went on record as to how he came up with the basic conception for his first paper of the annus mirabilis, a radical alternative to Maxwell’s theory of electromagnetic waves, which is the only one of his discoveries that he himself labeled as “revolutionary.” He says nothing directly about how he arrived at his first work on quantum theory in either his contemporary correspondence or in the papers preceding it. However, there are a few clues in the historical record, and these suggest that the key insight was his realization that the Planck radiation