Harold Urey

The discovery of deuterium and the marked differences in the physical and chemical properties of hydrogen and deuterium, together with an efficient method for the separation of these isotopes, have opened an interesting field of research in several of the major branches of science.

In general, exchange reactions for the lighter isotopes have equilibrium constants sufficiently different from unity, so that the ratios of concentrations of the isotopes in two compounds which are in equilibrium differ by a few per cents in nearly all cases.

Finding a 'sacrificial lamb' on whom to tag blame for complicated problems is an important instrument in the toolkit of politicians, because it deflects blame for the nation's economic woes away from their own regulatory lapses, economic mismanagement and coddling to labor unions.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.