Kindle Notes & Highlights
For him, even at this time, to know a theorem or a law meant chiefly to know how to use it.
He must have spent a tremendous amount of concentrated thought on the classics of physics, thoroughly assimilating them and distinguishing the important concepts and methods from the purely elegant ones, with unerring judgment.
knew that he was better than those around him, but this, he also knew, meant little, because these men were not in the forefront of active science. Moreover, although he had come in contact with eminent mathematicians, and although he was proficient in pure mathematics, he was not a professional mathematician and was little attracted to that discipline.
Activity in physics in Göttingen was then at its height. Born was professor of theoretical physics, James Franck was professor of experimental physics, and around these two men was a group of young people who were destined to change physics.
Fermi in those years regularly read most of the Zeitschrift für Physik and some of the other major journals. He thought deeply about what he read and was often inspired to add something new. This habit, which lasted until the time of his neutron work, helps to explain the vastness and universality of his knowledge.
To implement his program, therefore, Fermi took several practical steps that were to have important consequences. These were first, to write articles on modern physics intended for a wide audience, including high school teachers; second, to write a textbook devoted to atomic physics; and third, to seek out and train young physicists.
As before, lying on his stomach in a mountain meadow, armed with an adequate supply of pencils and of bound blank notebooks, he wrote page after page, without a book for consultation, without an erasure (there are no erasers on Italian pencils) or a word crossed out.
Unfortunately, my understanding of Rutherford’s English at the time was imperfect and I could not follow some of his remarks, which must have been humorous because he laughed with great glee.
We worked with incredible stubbornness. We would begin at eight in the morning and take measurements, almost without a break, until six or seven in the evening, and often later. The measurements were taken with a chronometric schedule, as we had studied the minimum time necessary for all the operations. They were repeated every three or four minutes, according to need, and for hours and hours for as many successive days as were necessary to reach a conclusion on a particular point.
After attending a seminar given by one of Oppenheimer’s pupils on Fermi’s beta-ray theory, Fermi met me and said: “Emilio, I am getting rusty and old. I cannot follow the highbrow theory developed by Oppenheimer’s pupils anymore. I went to their seminar and was depressed by my inability to understand them. Only the last sentence cheered me up; it was: ‘And this is Fermi’s theory of beta decay.’“
always with the thought that there could be no repetition in case of failure, a most unusual condition for an experimental physicist.
Fermi got up and dropped small pieces of paper on the ground. He had prepared a simple experiment to measure the energy liberated by the explosion:
the pieces of paper would fall at his feet in the quiet air, but when the front of the shock wave arrived (some seconds after the flash) the pieces of paper were displaced a few centimeters in the direction of propagation of the shock wave.
In any case Fermi gave science his utmost, and with him disappeared the last individual of our times to reach the highest summits in both theory and experiment and to dominate all of physics.
Here, as usual, they make little sense. I have every intention of summarizing only those papers which have something to say, neglecting all the more or less academic exercises, of which the scientific journals are full.
The trouble, more than just the lack of subject matter, is that to stretch the subject to the dimensions suitable for such a stupid work as a dissertation, I will be forced to add a fair amount of distilled water, and you well know my dislike of such a procedure. I shall see later.
Although the probability of winning is rather small, because as usual there will be applicants with twenty or more years’ experience, I want to try in any case — the more so since I have three rather important publications ready which might be considered as belonging to higher mechanics.
Impurities had to be eliminated to a surprisingly high extent from both uranium and graphite since the parasitic absorption due to elements appearing as common impurities in uranium and graphite was responsible for a loss of an appreciable fraction of the neutrons. The problem was tackled to organize large-scale production of many tons of graphite and uranium of an unprecedented purity.
All the operator has to do is to watch an instrument that indicates the intensity of the reaction and move the cadmium strips in if the intensity shows a tendency to rise, and out if the intensity shows a tendency to drop. To operate a pile is just as easy as to keep a car running on a straight road by adjusting the steering wheel when the car tends to shift right or left. After a few hours of practice an operator can keep easily the intensity of the reaction constant to a very small fraction of 1 percent.
