1906 - Science

Science

The third law of thermodynamics formulated by German chemist Walther H. (Herman) Nernst, 42, states that the specific heats of ordered solids at the absolute zero of temperature (-273.15° C.) become zero themselves. A professor at the University of Berlin, Nernst postulates that entropy has an absolute value, that crystalline materials have zero entropy at absolute zero, and that at temperatures above absolute zero all matter tends toward random motion and to dissipate; since extracting energy from a system becomes more and more difficult as that system approaches absolute zero, Nernst's theorem suggests the impossibility of reaching absolute zero, but his discovery will make it possible to calculate the actual values of constants that characterize chemical reactions (see Giauque, 1927; technology [Haber], 1908).

Astronomer and aviation pioneer Samuel P. Langley dies at Aiken, S.C., February 27 at age 71.

Italian-born Russian botanist Mikhail Semionovich Tsvett, 34, separates plant pigments by extracting them from leaves with ether and alcohol and then percolating the solution through a column of calcium carbonate. The technique he has invented as a University of Warsaw laboratory assistant will be called chromatography, and he will go on to discover new forms of chlorophyll, coining the term carotenoids.

Danish philologist Johan Ludvig Heiberg, 52, visits the Church of the Holy Sepulchre at Constantinople and discovers a prayer book whose text overlies what he recognizes as a copy of a treatise left by the mathematician Archimedes at his death in 212 B.C. (see 1200). Mold has obliterated some parts of the palimpsest, but Heiberg has the pages photographed, studies the photographs under a microscope, transcribes as much as he can make out, and publishes his transcription. The original palimpsest will disappear from the library, having probably been stolen (see 1930).

A monograph by Vermont-born Bryn Mawr geneticist Nettie Maria Stevens, 45, identifies the X and Y chromosomes, accurately pinpointing their role in determining the sex of an embryo (an XX combination produces a female, XY a male) (see McClung, 1901; Sutton, 1902). Stevens entered Stanford at age 35, received her bachelor's degree only 6 years ago, received her Ph.D from Bryn Mawr in 1903, and collaborated with Thomas Hunt Morgan 2 years ago on a paper about cytology and the regenerative process (see Morgan, 1909). Based on experiments with the Tenebrio molitor beetle, her paper establishes a relationship between cytology and heredity, but its implicit suggestion that a father "allows" the birth of a daughter by contributing his X chromosome offends some men; a similar work published independently and simultaneously by Stevens's former colleague Edmund Beecher Wilson is less specific in defining X and Y chromosomes.

Physicist Ludwig Boltzmann dies at Duino, Italy, September 5 at age 62, having worked to develop the science of statistical mechanics to explain and predict how the mass, charge, structure, and other properties of atoms determine the visible properties (e.g. diffusion, thermal conductivity, and viscosity) of matter. The symbol k will be called the "Boltzmann constant"; it has dimensions of energy per degree of temperature and occurs in nearly every statistical formulation of physics, whether classical or quantum.