ScienceWeek

WILLIAM THOMPSON (1824-1907) AND ESTABLISHED AUTHORITY

The following points are made by Lawrence S. Bartell (J. Chem. Educ. 2001 78:1059):

Lord Kelvin (William Thomson [1824-1907]) was such a brilliant scientist that he became perhaps the principal authority in matters of the physical universe. He applied the known laws of heat dissipation to the problem of the Earth's temperature. From the known temperature increase with distance below the surface, he deduced that the Earth was not nearly old enough for Darwin's estimates of the duration of certain geological processes or for his theory of the origin of the species to operate. He (Kelvin) also estimated the possible active lifetime of the Sun from its energy output, assuming that the energy source was gravitational infall. The result was more or less consistent with his conclusions about the age of the Earth.

Late in Kelvin's life, radiochemists confirmed the antiquity of the Earth proposed previously by geologists. Kelvin remained adamant that while the Earth might perhaps be 20 million years old, and just possibly an order of magnitude older, it could not possibly be billions of years old. What he had not reckoned with, of course, was the steady evolution of heat from the radioactive elements deep within the Earth or the nuclear reactions powering the Sun.

Kelvin also disputed Maxwell's theory of the electromagnetic nature of light, and proclaimed that heavier-than-air aircraft were impossible. This is not to disparage his genius and his enormous accomplishments, or even his genuine modesty. Even such giants can err, and that, itself, is a lesson worth learning.