Word: molecular
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Dates: during 1930-1939
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...zero or nearly zero, the positive charge is concentrated at one end, the negative at the other end. The distance between them is a factor in the dipole moment, which is, roughly speaking, a measure of electric leverage. Dr. Cohn measured the charges and the dipole moments by observing molecular behavior under a bombardment of radio waves. If some stimulus discharged the positive tension at one end, the negative charge would redistribute itself, affecting other molecules. If these molecules twitched in response to the charge, their movements would generate a current affecting still other molecules. Thus, like...
Thus the body of science is like a pyramid. The broad base rests on sense impressions. As one proceeds farther & farther from sense impressions, fewer & fewer systems are necessary to explain Nature, since each system explains more. Thus mechanics and heat are merged when heat is revealed as molecular motion. But this is far from the pyramid's base; a hand dipped in hot water feels heat, not motion. The apex of the pyramid, not yet reached, would be a single system containing the terms necessary to describe all phenomena...
...compound, however formed, that contains carbon, since carbon is a notable component of plants and animals. Lately Rockefeller Institute researchers have isolated in the form of crystals a virus which causes a plant disease called tobacco mosaic. The virus seems to consist of a protein molecule with a molecular weight of several million units. In most respects it is not alive; the crystal structure, for example, is typical of inanimate materials such as metal. But when it makes contact with plant tissue, the molecules at once acquire the ability to reproduce themselves-a prime prerequisite of life...
...cellulose membranes that form cell walls, a process of vital interest to textile technologists. Unable to see how plants manufacture their cellulose, botanists have supposed for a long time that the membranes were laid down in particles too small to be seen under the microscope. Researchers could estimate the molecular weight of cellulose at something around 162. but they could not find the exact weight, or the melting point of the pure substance, or the molecular architecture...
Thus Harlow Shapley, now about halfway along in his detailed census of the all-embracing Universe, was able to trace in Nature a continuous train of systems from the smallest known thing to the largest. Atoms with their electrons and nuclei are systems; so are molecules and molecular combinations such as crystals and colloids. Men, monkeys and chinch-bugs are colloidal aggregates. Then come meteoritic associations (comets, meteor streams), systems of satellites, stars, double and multiple stars, star clusters, galaxies, super-galaxies. Above all, the Universe of universes-the Metagalaxy. "That," says Harlow Shapley, "is as far as astronomy takes...