A Matter of Degrees

June 17, 2002
Segrè, a theoretical physicist at the University of Pennsylvania, begins this far-ranging survey of the history of science by explaining how living organisms maintain stable temperatures and showing how adaptations to hot or cold habitats influenced animal evolution. Subsequent chapters cover a wide range of topics such as the development of heat-measuring technologies; influences of temperature on earth's climate, including speculations on "snowball" and "slushball" earth scenarios and the greenhouse effect; survival mechanisms of thermophiles and psychrophiles (bacteria that tolerate extremely high and extremely low temperatures, respectively); and the role of neutrinos, tiny particles produced in the core of the sun, in explaining solar dynamics. Segrè observes that the history of human civilization can be read as a story of the "ever-hotter fires humans made as they moved from hunter-gatherers to villagers to toolmakers," while the formation of the universe can be seen as a vast cooling, from one hundred billion degrees at one hundredth of a second after the big bang to the cooler temperatures at which neutrons and protons could bind together (one billion degrees) and—some 300,000 years later—hydrogen and helium atoms could form (3,000 degrees). While some of Segrè's material will be a challenge to readers without knowledge of college-level physics, he brings humor and passion to his subject and excels in showing its relevance to both current policy and future research. Agents: John Brockmann and Katinka Matson.