- Email: [email protected]
Liquid helium
Oct., ~95o.]
Book
Rl,:\qEws
To this reviewer the last section is of greatest interest. It consists of four papers on the moon. l)r. Barnes presents a brief section on the scientific and engineering exploration of the ninon. Dr. Thomas Gold in his paper presents one side of the controversial "dust on the moon" question. His thesis is t h a t there is a deep layer of dust present on the moon. Immediately following this we find Dr. Fred Whipple's excellent paper on the lunar surface; he believes this deep dust layer is lacking. Finally, Dr. Gerard P. Kuiper presents his exploration of the moon. This last paper is a must for all interested in lunar features and detail. Dr. Kuiper has spent much time and energy researching lunar formations, and in this section his researches paint a picture of the past history of the moon. Some of the finest photographs of lunar detail illustrate Dr. Kuiper's paper. Vistas in Astronautics, Vol. 2 belongs in the library of thi)se who would keep abreast of developments in this revolutionary field. I. M. LEVITT Franklin Institute Planetarium LIQUID HELIUM, by K. R. Atkins. 312 pages, diagrams, 5½ × 8~ in. London, Cambridge University Press, 1959. Price, $11.00. Liquid helium is a fascinating substance. Composed of simple, monatomic molecules, interacting only through very weak van der Waal's forces, here is a material which by all reasonable expectation ought to be the very archetype of a simple fluid composed of hard spheres. On the contrary, it has properties which are so remarkable t h a t after fifty years of investigation fruitful experiments may still be performed with relatively simple equipment. Liquid helium (He*, the common stable isotope) has a critical point at 5.2°K, and 2.26 atmospheres pressure. From the critical point to the X-transfdrmation, which, under the saturated vapour, occurs a t 2.17 °K, the liquid is called helium I. Helium I is uot spectacular, although it does have some atypical properties, among which is a positive ternperature coefficient of viscosity. Below the transformation to the lowest temperatures reached, and presumably to absolute zero, the liquid phase persists. This liquid is called helium II.
323
Helitml 11 is unique in many ways, though perhaps the most striking single property is its "superfluidity," by which it is able to flow without friction through extremely narrow cracks and pores. This "superfluidity" has been termed a macroscopic manifestation of the q u a n t u m behavior which is characteristic of microscopic systems. In a brief introductory chapter, Prof. Atkins gives in broad outline the more unusual properties of liquid helium. This is followed by a detailed account of the equilibrium properties in chapter two. Chapter three contains an excellent summary of the theories which have been advanced to explain the equilibrium properties. Chapters four through seven are devoted to the transport properties of liquid helium and to the new thermohydrodynamics which must be developed to explain effects such as superfluidity, second sound, and the peculiar viscous effects found in rotating liquid helium II. Chapter eight is devoted to the strange twin of liquid He 4, namely liquid He*. The stable light isotope of helium is present in well helium to the extent of about 1.4 parts in 10 7 but is now available in reasonable quantities from the radioactive decay of reactor produced tritium. The properties of the liquid He 3 are complementary to those of liquid He 4. There is no k transformation or "superfluidity" b u t the liquid state persists apparently to absolute zero. The ninth and last chapter is devoted to solutions of He a in liquid He 4 and to the additional insight into the properties of liquid helium which can be obtained from studies of these solutions. It is a pleasure to review a book on this subject by an author who has himself contributed much to our understanding of the properties of liquid helium, and whose infectuous enthusiasm should arouse a response ira even the most casual reader. This book will be an asset on the bookshelf of any physicist, and invaluable to anyone contemplating research at liquid helium temperatures, or on the theory of the liquid state. There is one small criticism, and this is directed toward the publisher, rather than to the author. W h y are most of the figures on the overleaf? F. J. DONAHOE The Franklin Institute Laboratories
Book
Rl,:\qEws
To this reviewer the last section is of greatest interest. It consists of four papers on the moon. l)r. Barnes presents a brief section on the scientific and engineering exploration of the ninon. Dr. Thomas Gold in his paper presents one side of the controversial "dust on the moon" question. His thesis is t h a t there is a deep layer of dust present on the moon. Immediately following this we find Dr. Fred Whipple's excellent paper on the lunar surface; he believes this deep dust layer is lacking. Finally, Dr. Gerard P. Kuiper presents his exploration of the moon. This last paper is a must for all interested in lunar features and detail. Dr. Kuiper has spent much time and energy researching lunar formations, and in this section his researches paint a picture of the past history of the moon. Some of the finest photographs of lunar detail illustrate Dr. Kuiper's paper. Vistas in Astronautics, Vol. 2 belongs in the library of thi)se who would keep abreast of developments in this revolutionary field. I. M. LEVITT Franklin Institute Planetarium LIQUID HELIUM, by K. R. Atkins. 312 pages, diagrams, 5½ × 8~ in. London, Cambridge University Press, 1959. Price, $11.00. Liquid helium is a fascinating substance. Composed of simple, monatomic molecules, interacting only through very weak van der Waal's forces, here is a material which by all reasonable expectation ought to be the very archetype of a simple fluid composed of hard spheres. On the contrary, it has properties which are so remarkable t h a t after fifty years of investigation fruitful experiments may still be performed with relatively simple equipment. Liquid helium (He*, the common stable isotope) has a critical point at 5.2°K, and 2.26 atmospheres pressure. From the critical point to the X-transfdrmation, which, under the saturated vapour, occurs a t 2.17 °K, the liquid is called helium I. Helium I is uot spectacular, although it does have some atypical properties, among which is a positive ternperature coefficient of viscosity. Below the transformation to the lowest temperatures reached, and presumably to absolute zero, the liquid phase persists. This liquid is called helium II.
323
Helitml 11 is unique in many ways, though perhaps the most striking single property is its "superfluidity," by which it is able to flow without friction through extremely narrow cracks and pores. This "superfluidity" has been termed a macroscopic manifestation of the q u a n t u m behavior which is characteristic of microscopic systems. In a brief introductory chapter, Prof. Atkins gives in broad outline the more unusual properties of liquid helium. This is followed by a detailed account of the equilibrium properties in chapter two. Chapter three contains an excellent summary of the theories which have been advanced to explain the equilibrium properties. Chapters four through seven are devoted to the transport properties of liquid helium and to the new thermohydrodynamics which must be developed to explain effects such as superfluidity, second sound, and the peculiar viscous effects found in rotating liquid helium II. Chapter eight is devoted to the strange twin of liquid He 4, namely liquid He*. The stable light isotope of helium is present in well helium to the extent of about 1.4 parts in 10 7 but is now available in reasonable quantities from the radioactive decay of reactor produced tritium. The properties of the liquid He 3 are complementary to those of liquid He 4. There is no k transformation or "superfluidity" b u t the liquid state persists apparently to absolute zero. The ninth and last chapter is devoted to solutions of He a in liquid He 4 and to the additional insight into the properties of liquid helium which can be obtained from studies of these solutions. It is a pleasure to review a book on this subject by an author who has himself contributed much to our understanding of the properties of liquid helium, and whose infectuous enthusiasm should arouse a response ira even the most casual reader. This book will be an asset on the bookshelf of any physicist, and invaluable to anyone contemplating research at liquid helium temperatures, or on the theory of the liquid state. There is one small criticism, and this is directed toward the publisher, rather than to the author. W h y are most of the figures on the overleaf? F. J. DONAHOE The Franklin Institute Laboratories