Join 📚 Roger's Highlights
A batch of the best highlights from what roger's read, .
Of this much they were now certain: such a bomb was practical. The hypothesis had been sound from the outset, but there had been a hitch in its application. In theory, a chain reaction should have developed when neutrons were introduced into a U-235 pile. The neutrons would split the U-235 atoms, each of which would liberate from one to three neutrons—which, in turn, would split more atoms, and so on, until the critical mass was reached. Obviously they couldn’t permit that mass to form in a laboratory; that was why they used graphite, to slow neutrons down while they observed the process. In practice, they found, some neutrons went astray and some were “cannibalized” by the pile. A chain reaction was possible only if successive “generations” of neutrons became larger and larger. This was christened the K factor, otherwise known as “the great god K.” It was reached under the following conditions. If 100 neutrons which had caused fission in 100 U-235 atoms gave birth to a generation of new neutrons, 105 of which were left to cause fission, the ratio would be 105 to 100, and the K factor would have a value of 1.05. The third generation would be 105 multiplied by 1.05, and so on, until the mass was formed. As William L. Laurence put it, “When the K factor is greater than one, the pile will be chain-reacting, as the birth rate will be greater than the death rate.” Conversely, if 100 neutrons produced only 99, the K factor, 0.99, would be inadequate. By purifying the graphite in early experiments, the best they could get in those early months was a birth rate of .87 per 100. Their greatest problem lay in the impurity of the uranium. Dr. Arthur H. Compton called the Westinghouse director of research and—at a time when the world’s total hoard of pure uranium metal did not exceed a few grams—asked him, “How soon can Westinghouse supply three tons of pure uranium?” He heard a gagging sound at the other end of the line, but the firm’s response was an illustration of American industry’s versatility in World War II. Uranium fabrication was stepped up from eight ounces a day to over five hundred pounds, and by November 1942 Westinghouse had delivered the three tons. The delivery address could hardly have aroused less interest. On Ellis Avenue in Chicago, between Fifty-sixth and Fifty-seventh streets, the ivied Gothic walls of University of Chicago buildings parted to reveal a recess and, within, a door. Beyond that door was a large squash court which had been unused since the outbreak of war. The court lay directly beneath the west stands of Stagg Field, and scarcely anyone had come this way since the university had abandoned intercollegiate football. It was there, that November, that a pile of unprecedented size was being assembled with materials of unique purity. Two carbon companies, working with the National Bureau of Standards, had turned out a graphite highly resistant to neutrons. Other bureau scientists had joined Professor Frank H. Spedding of Iowa…
The Glory and the Dream
William Manchester
Central to Simon and Newell’s theory was the idea that problem solving is a search through a problem space.
Get Better at Anything
Scott Young
What, then, is the future of the $5 trillion global oil and gas industry that supplies almost 60 percent of world energy? The industry will continue to need to find and develop another three to five billion barrels a year just to make up for the natural decline in oil fields, which happens after a field has been in production for some time. The International Energy Agency estimates that over $20 trillion of investment in oil and gas development will be required over the next two decades.
The New Map
Daniel Yergin
...catch up on these, and many more highlights
Readwise