Nobel lecture december 12, 1933 On passing through an optical instrument, such as a telescope or a camera lens, a ray of light is subjec reflecting surface. The path of the rays can be constructed if we know the two simple laws which govern the changes in direction: the law of refrac- tion which was discovered by Snellius a few hundred years ago, and the law of reflection with which Archimedes was familiar more than 2,000 years ago
That streams of electrons possess the properties of beams of waves was dis- covered early in 1927 in a large industrial laboratory in the midst of a great city, and in a small university laboratory overlooking a cold and desolate sea. The coincidence seems the more striking when one remembers that facil- ities for making this discovery had been in constant use in laboratories throughout the world for more than a quarter of a century. And yet the coincidence was not, in fact, in any way remarkable. Discoveries in physics are made when the time for making them is ripe, and not before; the stage is set, the time is ripe, and the event occurs-more often than not at widely separated places at almost the same moment