The Cover · · ·
liiauip Awarded M e l Prize for Low Temperature Research χ H E world's highest chemical honor has just been awarded to William Francis Giauque, professor of chemistry at the University of California, for his re search in the fundamental properties of matter at low temperatures. Dr. Giauque (pronounced jee-oak) has measured the specific heats of many chemicals from room temperature down to the region near absolute zero, where the specific heat vanishes. These data permit the calculation of the entropies, which can then be combined with the heats of chemical reactions, and which serve therefore to predict the direction and extent of these reactions. Such experiments, although arduous and timeconsuming, have been carried out with a precision never surpassed. The theory for the correlation of entropies and free energies with spec troscopic data was developed by Giau que. This theory permits the calcula tion of these quantities with a degree of accuracy often exceeding that of direct measurement. Hitherto unsus pected processes have been discovered at extremely low temperatures. In 1924 D r . Giauque calculated the order of magnitude of entropy changes produced at low temperatures by mag neticfields.H e concluded that it would be possible, by a magnetic method, to reach temperatures considerably below those that had previously been ob tained by the standard method of helium evaporation at low pressures. The first experimental demonstration of the prin ciple was carried out by Giauque and MacDougall on March 19, 1933. B y this method the attainable temperature has been lowered at the University of Leyden from about 1° Absolute by the evaporation of helium, to about 0.004° Absolute by the magnetic method. This has opened up newfieldsof research into the properties of the fundamental particles and of degenerate states of matter. In 1928, Dr. Giauque and H . L . Johns ton, then one of his graduate students and now professor of chemistry at Ohio State University, were engaged in cal culating the entropy of the oxygen molecule from the absorption bands of atmospheric oxygen. They were puzzled by the existence of a weak absorption band in oxygen for which no explana tion had been offered. Giauque then found that a complete quantitative in terpretation of the band resulted from the assumption that it was due to an isotope of oxygen, of mass 18. Shortly
VOLUME
2 7,
NO.
thereafter, another isotope of mass 17 was found in the same way. Because all atomic weights are based on the value 16 arbitrarily assigned to oxygen, it is safe to assume that the existence of oxygen isotopes was about the last thing scientists had expected. A s a result of this discovery w e now have two scales of atomic weight, one based on the ordinary mixture of oxygen iso topes taken as 16, and the other based on the lightest isotope taken as 16. The two scales differ by nearly 1 part in 3,000. Discovers Oxygen Isotopes This discovery of oxygen isotopes from spectroscopic data paved the way to the discovery by others, using the same method, of isotopes of carbon and nitro gen, andfinallyof the very important hydrogen 2 isotope known as deuterium. Dr. Giauque and D r . Johnston were the first to demonstrate the predicted existence of the ortho and para forms of the hydrogen molecule. They did this byfindinga change in the pressure of hydrogen at the triple point, after it had been held for a long time at liquid air temperature. These two forms of the hydrogen molecule differ in that the spins of the two protons are parallel in one form and antiparallel in the other. During World W a r II Giauque de signed a successful mobile unit for the production of oxygen. In 1929 he was awarded the Pacific Division prize of the A A AS for his discovery, with Dr. Johnston, of the oxygen isotopes. In 1936 he was lecturer and medalist of the Charles Frederick Chandler Founda tion of Columbia University. In 1937 he received the Elliott Cresson medal of the Franklin Institute. Both awards were made for his discovery of the adiabatic demagnetization method for pro ducing temperatures approaching abso lute zero. H e was awarded the honor ary degree of doctor of science by Columbia University in 1936 and was also elected a member of the National Academy of Sciences. In 1940 he be came a member of the American Philo sophical Society. What sort of a person is Giauque— the man? H e was born at Niagara Falls, Ont., on M a y 12, 1895. His father was born in Iowa and his mother in Canada. Following graduation from high school he spent two years at Hooker Electro chemical laboratory, Niagara Falls. J. W . Beckman, a chemical consultant, and
48» N O V E M B E R
2 8,
194
9
his wife, suggested the University of California, and he himself, decided to study chemistry at that school. His oustanding mentality, apparent even in his freshman year, impressed the in structors so that upon receipt of the Ph.D. degree in 1922 he was appointed to the staff of the department of chem istry, becoming a full professor in 1934. Giauque is not a "remote control" thesis adviser. Instead he energizes his research students by example. In the earlier days of the research effort, he often worked with his students all night long. Sleep, rest, in fact, everything was of secondary importance compared with his low temperature experiments. The important philosophy was always, "keep the experiment running." A d miration by his students seems to be in direct proportion to the grueling pace he still expects of them. Popular with Students Swimming is one of D r . Giauque'e main extracurricular accomplishments. Before he was married, 8 to 10 of his students used to share the outdoor life with him, his outboard motorboat, and skiff. A few weeks of this summer "roughing it" made possible a very close understanding between teacher and stu dent that carried over during the ardu ous periods back at Berkeley. According to the tradition of the Uni versity of California chemistry depart ment, D r . Giauque continues to teach freshmen laboratory sections. In addi tion, he teaches thermodynamics and advanced physical chemistry, and super vises the research of graduate students. Dr. Giauque's wife, Muriel Frances (nee Ashley), is also a scientist, having received the P h . D . in physics at Berke ley. Her interests are varied for at the present time she is studying botanical problems. Their two sons, William Francis Ashley Giauque, 15, and Robert David Ashley Giauque, 12, attend Berkeley schools. Dr. Giauque is by nature serious and intense. H e abhors publicity, and avoids most social functions because he finds other things much more interesting. H e earnestly wishes that there might have been some unostentatious way to be awarded the Nobel prize. His ability to see all sides of a scien tific problem might be traced in part to his early schooling, which was both in Canada and the United States. O n one side of the border, teachers empha sized the British victories in the war of 1812, and on the other side, the U . S. viewpoint was stressed. In answering history questions, young Giauque had to remember which side of the border he was on. Although he leaves conflirting historical viewpoints for others to worry about, the Giauque approach to con flicting scientific theories is "Let's work toward but one end—the truth."
3571
