“Knowledge,” Niels Bohr once noted, “is itself the basis for civilization.” You cannot have the one without the other; the one depends upon the other. Nor can you have only benevolent knowledge; the scientific method doesn’t filter for benevolence.
earth. “It is a profound and necessary truth,” Robert Oppenheimer would say, “that the deep things in science are not found because they are useful; they are found because it was possible to find them.”
Bohr proposed once that the goal of science is not universal truth. Rather, he argued, the modest but relentless goal of science is “the gradual removal of prejudices.” The discovery that the earth revolves around the sun has gradually removed the prejudice that the earth is the center of the universe. The discovery of microbes is gradually removing the prejudice that disease is a punishment from God. The discovery of evolution is gradually removing the prejudice that Homo sapiens is a separate and special creation.
Only very rarely does an animal living under natural conditions in the wild die of old age. Until recently, the human world was not much different. Since we are predators, at the top of the food chain, our worst natural enemies historically have been microbes. Natural violence, in the form of epidemic disease, took a large and continuous toll of human life, such that very few human beings lived out their natural lifespans. By contrast, man-made death—death, that is, by war and war’s attendant privations—persisted at a low and relatively constant level throughout human history, hardly distinguishable in the noise of the natural toll. The invention of public health in the nineteenth century, and the application of technology to war in the nineteenth and twentieth centuries, inverted that pattern in the industrialized world. Natural violence—epidemic disease—retreated before the preventive methodologies of public health to low and controlled levels. At the same time, man-made death began rapidly and pathologically to increase, reaching horrendous peaks in the twentieth century’s two world wars. Man-made death accounted for not fewer than 200 million human lives in that most violent of all centuries in human history, a number that the Scottish writer Gil Elliot vividly characterizes as a “nation of the dead.”
In 2008, some of the scientists who modeled the original 1983 nuclear winter scenario investigated the likely result of a theoretical regional nuclear war between India and Pakistan, a war they postulated to involve only 100 Hiroshima-scale nuclear weapons, yielding a total of only 1.5 megatons—no more than the yield of some single warheads in the U.S. and Russian arsenals. They were shocked to discover that because such an exchange would inevitably be targeted on cities filled with combustible materials, the resulting firestorms would inject massive volumes of black smoke into the upper atmosphere which would spread around the world, cooling the earth long enough and sufficiently to produce worldwide agricultural collapse. Twenty million prompt deaths from blast, fire, and radiation, Alan Robock and Owen Brian Toon projected, and another billion deaths in the months that followed from mass starvation—from a mere 1.5-megaton regional nuclear war.
On the weekend of April 1, Julius Streicher directed a national boycott of Jewish businesses and Jews were beaten in the streets. “I took a train from Berlin to Vienna on a certain date, close to the first of April, 1933,” Szilard writes. “The train was empty. The same train the next day was overcrowded, was stopped at the frontier, the people had to get out, and everybody was interrogated by the Nazis. 73 This just goes to show that if you want to succeed in this world you don’t have to be much cleverer than other people, you just have to be one day earlier.”
if we could find an element which is split by neutrons and which would emit two neutrons when it absorbs one neutron, such an element, if assembled in sufficiently large mass, could sustain a nuclear chain reaction.
purely mechanical atoms violated the second law of thermodynamics. His choice was clear. The second law specifies that heat will not pass spontaneously from a colder to a hotter body without some change in the system. Or, as Planck himself generalized it in his Ph.D. dissertation at the University of Munich in 1879, that “the process of heat conduction cannot be completely reversed by any means.” Besides forbidding the construction of perpetual-motion machines, the second law defines what Planck’s predecessor Rudolf Clausius named entropy: because energy dissipates as heat whenever work is done—heat that cannot be collected back into useful, organized form—the universe must slowly run down to randomness. 89 This vision of increasing disorder means that the universe is one-way and not reversible; the second law is the expression in physical form of what we call time. But the equations of mechanical physics—of what is now called classical physics—theoretically allowed the universe to run equally well forward or backward. “Thus,” an important German chemist complained, “in a purely mechanical world, the tree could become a shoot and a seed again, the butterfly turn back into a caterpillar, and the old man into a child. No explanation is given by the mechanistic doctrine for the fact that this does not happen… .
The best way to do the job, Polanyi argued, was to allow each worker to keep track of what every other worker was doing. “Let them work on putting the puzzle together in the sight of the others, so that every time a piece of it is fitted in by one [worker], all the others will immediately watch out for the next step that becomes possible in consequence.” That way, even though each worker acts on his own initiative, he acts to further the entire group’s achievement. 104 The group works independently together; the puzzle is assembled in the most efficient way.
“Physics,” as Eugene Wigner once reminded a group of his fellows, “does not even try to give us complete information about the events around us—it gives information about the correlations between those events.” 108
He studied the radiations emitted by uranium and thorium and named two of them: “There are present at least two distinct types of radiation—one that is very readily absorbed, which will be termed for convenience the α [alpha] radiation, and the other of a more penetrative character, which will be termed the β [beta] radiation.” 137 (A
Soddy and Rutherford had observed the spontaneous disintegration of the radioactive elements, one of the major discoveries of twentieth-century physics. 142 They set about tracing the way uranium, radium and thorium changed their elemental nature by radiating away part of their substance as alpha and beta particles. They discovered that each different radioactive product possessed a characteristic “half-life,” the time required for its radiation to reduce to half its previously measured intensity. The half-life measured the transmutation of half the atoms in an element into atoms of another element or of a physically variant form of the same element—an “isotope,” as Soddy later named it. 143 Half-life became a way to detect the presence of amounts of transmuted substances—“decay products”—too small to detect chemically. The half-life of uranium proved to be 4.5 billion years, of radium 1,620 years, of one decay product of thorium 22 minutes, of another decay product of thorium 27 days. Some decay products appeared and transmuted themselves in minute fractions of a second—in the twinkle of an eye. It was work of immense importance to physics, opening up field after new field to excited view, and “for more than two years,” as Soddy remembered afterward, “life, scientific life, became hectic to a degree rare in the lifetime of an individual, rare perhaps in the lifetime of an institution.” 144
He announced his recent confirmation, only briefly reported the month before, that the alpha particle was in fact helium. 156 The confirming experiment was typically elegant. Rutherford had a glassblower make him a tube with extremely thin walls. He evacuated the tube and filled it with radon gas, a fertile source of alpha particles. The tube was gastight, but its thin walls allowed alpha particles to escape. Rutherford surrounded the radon tube with another glass tube, pumped out the air between the two tubes and sealed off the space. “After some days,” he told his Stockholm audience triumphantly, “a bright spectrum of helium was observed in the outer vessel.” Rutherford’s experiments still stun with their simplicity. 157 “In this Rutherford was an artist,” says a former student. “All his experiments had style.” 158
Chaim Weizmann, the Russian-Jewish biochemist who was later elected the first president of Israel, was working at Manchester on fermentation products in those days. He and Rutherford became good friends.
Lenard dramatized his findings with a vivid metaphor: the space occupied by a cubic meter of solid platinum, he said, was as empty as the space of stars beyond the earth.
To do so he needed not only to count but also to see individual alpha particles. At Manchester he accepted the challenge of perfecting the necessary instruments. He worked with Hans Geiger to develop an electrical device that clicked off the arrival of each individual alpha particle into a counting chamber. Geiger would later elaborate the invention into the familiar Geiger counter of modern radiation studies.
The method of finding the wavelengths is to reflect the X rays which come from a target of the element investigated [when such a target is bombarded with cathode rays]… . I have then merely to find at which angles the rays are reflected, and that gives the wavelengths. I aim at an accuracy of at least one in a thousand. 308
Phosgene then became a staple of the war, dispensed from cylinders, artillery shells, trench mortars, canisters fired from mortarlike “projectors” and bombs. It smelled like new-mown hay but it was by far the most toxic gas used, ten times as toxic as chlorine, fatal in ten minutes at a concentration of half a milligram per liter of air. At higher concentrations one or two breaths killed in a matter of hours. Phosgene—carbonyl chloride—hydrolyzed to hydrochloric acid in contact with water; that was its action in the water-saturated air deep in the delicate bubbled tissue of the human lung. It caused more than 80 percent of the war’s gas fatalities.
The most horrible gas of the war, the gas that started a previously complacent United States developing a chemical-warfare capacity of its own, was dichlorethyl sulfide, known for its horseradish- or mustard-like smell as mustard gas. 349 The Germans first used it on the night of July 17, 1917, in an artillery bombardment against the British at Ypres.
Gas in any case was far less efficient at maiming and killing men than were artillery and machine-gun fire. Of a total of some 21 million battle casualties gas caused perhaps 5 percent, about 1 million. It killed at least 30,000 men, but at least 9 million died overall. Gas may have evoked special horror because it was unfamiliar and chemical rather than familiar and mechanical in its effects.
Economic take-off, the late introduction of a nation rich in agricultural resources to the organizing mechanisms of capitalism and industrialization, was responsible for Hungary’s boom. The operators of those mechanisms, by virtue of their superior ambition and energy but also by default, were Jews, who represented about 5 percent of the Hungarian population in 1910. The stubbornly rural and militaristic Magyar nobility had managed to keep 33 percent of the Hungarian people illiterate as late as 1918 and wanted nothing of vulgar commerce except its fruits. 384 As a result, by 1904 Jewish families owned 37.5 percent of Hungary’s arable land; by 1910, although Jews comprised only 0.1 percent of agricultural laborers and 7.3 percent of industrial workers, they counted 50.6 percent of Hungary’s lawyers, 53 percent of its commercial businessmen, 59.9 percent of its doctors and 80 percent of its financiers. 385, 386 The only other significant middle class in Hungary was a vast bureaucracy of impoverished Hungarian gentry that came to vie with the Jewish bourgeoisie for political power. Caught between predominantly Jewish socialists and radicals on one side and the entrenched bureaucracy on the other, both sides hostile, the Jewish commercial elite allied itself for survival with the old nobility and the monarchy; one measure of that conservative alliance was the dramatic increase in the early twentieth century of ennobled Jews.
Around the nucleus, Bohr proposed, atoms are built up of successive orbital shells of electrons—imagine a set of nested spheres—each shell capable of accommodating up to a certain number of electrons and no more. Elements that are similar chemically are similar because they have identical numbers of electrons in their outermost shells, available there for chemical combination.
in German, the Erzgebirge: the Ore Mountains. The Erzgebirge began to be mined for iron in medieval days. In 1516 a rich silver lode was discovered in Joachimsthal (St. Joachim’s dale), in the territory of the Count von Schlick, who immediately appropriated the mine. In 1519 coins were first struck from its silver at his command. Joachimsthaler, the name for the new coins, shortened to thaler, became “dollar” in English before 1600. Thereby the U.S. dollar descends from the silver of Joachimsthal.
The same is true of particles and waves of matter. The reason both could be accepted as valid is that “particles” and “waves” are words, are abstractions. What we know is not particles and waves but the equipment of our experiments and how that equipment changes in experimental use. The equipment is large, the interiors of atoms small, and between the two must be interposed a necessary and limiting translation.
Newspapers soon published the discovery in plainer words: Sir Ernest Rutherford, headlines blared in 1919, had split the atom. It was less a split than a transmutation, the first artificial transmutation ever achieved. When an alpha particle, atomic weight 4, collided with a nitrogen atom, atomic weight 14, knocking out a hydrogen nucleus (which Rutherford would shortly propose calling a proton), the net result was a new atom of oxygen in the form of the oxygen isotope 017: 4 plus 14 minus 1. There would hardly be enough 017 to breathe; only about one alpha particle in 300,000 crashed through the electrical barrier around the nitrogen nucleus to do its alchemical work.
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