The Stranger Story of the Quantum
In 1913 a distinguished group of German scientists, including Max Planck, wrote a letter of recommendation for Einstein to the Prussian Academy of Sciences, of which they were members. Einstein was only 34, but his reputation was already such that they thought that he should be elected to their illustrious society in Berlin. The final paragraph of this letter is a gem. It reads: [In sum, one can say that there is hardly one among the great problems, in which modern physics is so rich, which Einstein has not made some remarkable contribution. That he may sometimes have missed the target in his speculations as, for example, in his hypothesis of light quanta cannot really be held against him, for it is not possible to introduce really new ideas, even in the most exact sciences, without sometimes taking a risk.]
In short, Planck, one of the authors of this remarkable document, was saying even in 1913 that the idea of light quanta [missed the target] and should not be held against Einstein. Planck, who had devised the idea of quanta, still was unable to grasp the significance of his own creation.
When we left quantum physics it was 1906, and Einstein was still the dominant figure in it. He had just