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Cosmology — The Science of the universe
total small.
number of all
WR stars
catalogued
is
still
relatively
Questions of mass loss through winds and of evolution ageing processes held the attention of through stellar participants at Cozumel in Mexico where the September 1981 meeting on WR objects was held. The reason why hot star symposia can be convened at such relatively frequent intervals stems historically from the impetus provided by the advent of sophisticated space instrumentation such as the IUE and the EINSTEIN satellite. Mass loss binary systems involving WR model building for those very exciting objects components, received proper and careful attention and exposition at Cozumel. A special feature of the Cozumel symposium was the prominence accorded to the role of the WR stars in the Magellanic Clouds plus the report of the first detection of WR objects in M 31. Another was the report of X-Ray data for a number of WR stars. The discussion is well presented and in depth, sufficient for communication among the participants and illumination for the non specialist readers. References, tracings of spectra are all of high quality. The figures, breakthrough researches by space telescopes especially in the UV but also now in the IR certainly are setting the pace for studies in this field and stimulate greater efforts of land based observers who have been very busy even with the excellent high speed data reduction capabilities so prominently in evidence in the papers presented at Cozumel. The role and interplay of abundance and age in stellar evolutionary processes still remains a complex mystery. These discussions are well reported and interesting to read. The subject index is good. There are no object or personal indices.
M. F. McCarthy,
S.J.
Cosmology - The Science of the Universe Edward R. Harrison Press, Cambridge. XI + 43opp., Cambridge University London etc. 1981 Trumpington Street, Cambridge CB2 lRP, UK 32 East Street, New York, NY 10022, USA. (No price indicated). This is a remarkable book. To review all of its aspects would require an extensive article. Therefore, I shall concentrate upon the author's views of cosmology as a science and its cultural functions. The first chapters of the book
120
deal with these problems directly, and, in a sense, the entire book is aimed at allowing cosmology to present its own meaning and role in the shaping of our image of the world in which we ourselves seem to be an essential component. Cosmology, in a narrrow sense, is "the science of the the universe: of the realm of large-scale structure of extragalactic nebulae, of distant and receding horizons, of the interplay of cosmic forces, and of the dynamic curvature of universal space and time" Books and papers on (P. IX). modern cosmology traditionally cover all these subjects. Professor Harrison goes far beyond the traditional domain; he is fascinated by a cosmology, understood in a broader sense, that is "the grand science that seeks forever to assemble all knowledge into a world picture" (ibid). This world picture contains man, together with all his beliefs, desires and existential problems. Cosmology, in this sense, can be treated as a "mighty frame" within which all pieces should fit together. Such a cosmology cannot avoid dealing with the history of man's quest for understanding the world and the history of world pictures that have shaped our culture. Although the book is principally a responsible popularization of cosmology in the narrow sense, the reader can find in it many sections dealing with the history of cosmological ideas and their philosophical ramifications. Every chapter is collecting quotations, supplemented with "Reflections" thoughts, short considerations having the character of broader comments on main topics of a given chapter. If one defines cosmology as the science of the universe, one should carefully distinguish between two concepts, namely between "the Universe" and "the universe". The Universe is the unity that embraces the diverse (p. 10). It has many faces or "models": philosophical, scientific,.... religious, artistic, Behind all these faces a Great Unknown is hidden, and we must be careful not to mistake "the mask for the face, the model I n order for the Universe" (ibid.). not to commit this error, it is better to speak of the universe. "A universe is simply a model of the Universe" (p.11). In this sense one speaks of the Pythagorean universe, of the Medieval universe or of the scientific universe of the twentieth century. In this perspective, the role of modern cosmology is beautifully visible: on the one hand, cosmology endeavors to put the pieces, collected by other sciences, together in order to see a global picture of the jigsaw puzzle; on the other side, it does this in a very selective manner, and consequently, the global picture is highly polarized. The polarization in question is called by Harrison the containment principle which states: "The physical universe contains everything that is physical, and nothing else" (p. 100). These are not philosophical likes or dislikes of cosmologists that induce 121
them to put outside the realm of comsmological science everything which is non-physical; this strategy belongs to the very essence of experimental science. Harrison's containment principle is not a "declaration of an outrageous philosophy" (ibid.) but a purely methodological principle. When we use the above strategy, it works smoothly. When we begin to reflect upon what we are doing, this starts to produce paradoxes. One of them in Harrison's terminology, and may be reduced to the bears the name "containment riddle", "where in a universe can be found the following question: cosmologist conceiving that universe?" (p. 115) If the universe contained not only the body of the cosmologist but also his mind, the universe would contain the cosmologist whose mind would contain the universe,... and so on ad infinitum; a typical multi-mirror situation. The cosmologist inhabits the Universe but he is clearly outside the universe he has created. As if on the margin the author makes the following remark: "Those people who cannot agree with this proposition, and claim that life and mind are no more than a collective dance of atoms, must answer the containment riddle" (p. 116). containment The principle proves to be a useful methodological tool in analyzing other philosophical problems, the creation problem. Here also one should distinguish I.e., the concepts "Creation" and "creation". Creation (with a capital C) is the justification for the existence of the Universe whereas creation attempts to explain the origin of matter in an already existing universe (e.g. creation of particles in the steady-state world model). Of course, because of the containment principle in cosmology, only the question of the creation can appear. On the other hand, however, if somebody invokes a cosmological model presenting an infinitely old universe (e.g. the steady-state model or EddingtonLemaitre model) in order to discard the Creation doctrine, somebody commits a logical error. No model of the universe can explain the existence of the Universe. "An infinite span of time" - writes Harrison - "has to be created in the same way as a finite span of time." (p. 110) One should not conclude, however, that "The Science of the Universe" is a philosophical monograph. First of all, it and it ought to be read as, a good popularization of is, scientific cosmology, and in every good popularization of science there must be a touch of philosophy. Methodological distinctions are indispensable in order not to confuse science and philosophy but each scientist is a human being who asks both questions and Questions. Michael
122
Heller
number of all
WR stars
catalogued
is
still
relatively
Questions of mass loss through winds and of evolution ageing processes held the attention of through stellar participants at Cozumel in Mexico where the September 1981 meeting on WR objects was held. The reason why hot star symposia can be convened at such relatively frequent intervals stems historically from the impetus provided by the advent of sophisticated space instrumentation such as the IUE and the EINSTEIN satellite. Mass loss binary systems involving WR model building for those very exciting objects components, received proper and careful attention and exposition at Cozumel. A special feature of the Cozumel symposium was the prominence accorded to the role of the WR stars in the Magellanic Clouds plus the report of the first detection of WR objects in M 31. Another was the report of X-Ray data for a number of WR stars. The discussion is well presented and in depth, sufficient for communication among the participants and illumination for the non specialist readers. References, tracings of spectra are all of high quality. The figures, breakthrough researches by space telescopes especially in the UV but also now in the IR certainly are setting the pace for studies in this field and stimulate greater efforts of land based observers who have been very busy even with the excellent high speed data reduction capabilities so prominently in evidence in the papers presented at Cozumel. The role and interplay of abundance and age in stellar evolutionary processes still remains a complex mystery. These discussions are well reported and interesting to read. The subject index is good. There are no object or personal indices.
M. F. McCarthy,
S.J.
Cosmology - The Science of the Universe Edward R. Harrison Press, Cambridge. XI + 43opp., Cambridge University London etc. 1981 Trumpington Street, Cambridge CB2 lRP, UK 32 East Street, New York, NY 10022, USA. (No price indicated). This is a remarkable book. To review all of its aspects would require an extensive article. Therefore, I shall concentrate upon the author's views of cosmology as a science and its cultural functions. The first chapters of the book
120
deal with these problems directly, and, in a sense, the entire book is aimed at allowing cosmology to present its own meaning and role in the shaping of our image of the world in which we ourselves seem to be an essential component. Cosmology, in a narrrow sense, is "the science of the the universe: of the realm of large-scale structure of extragalactic nebulae, of distant and receding horizons, of the interplay of cosmic forces, and of the dynamic curvature of universal space and time" Books and papers on (P. IX). modern cosmology traditionally cover all these subjects. Professor Harrison goes far beyond the traditional domain; he is fascinated by a cosmology, understood in a broader sense, that is "the grand science that seeks forever to assemble all knowledge into a world picture" (ibid). This world picture contains man, together with all his beliefs, desires and existential problems. Cosmology, in this sense, can be treated as a "mighty frame" within which all pieces should fit together. Such a cosmology cannot avoid dealing with the history of man's quest for understanding the world and the history of world pictures that have shaped our culture. Although the book is principally a responsible popularization of cosmology in the narrow sense, the reader can find in it many sections dealing with the history of cosmological ideas and their philosophical ramifications. Every chapter is collecting quotations, supplemented with "Reflections" thoughts, short considerations having the character of broader comments on main topics of a given chapter. If one defines cosmology as the science of the universe, one should carefully distinguish between two concepts, namely between "the Universe" and "the universe". The Universe is the unity that embraces the diverse (p. 10). It has many faces or "models": philosophical, scientific,.... religious, artistic, Behind all these faces a Great Unknown is hidden, and we must be careful not to mistake "the mask for the face, the model I n order for the Universe" (ibid.). not to commit this error, it is better to speak of the universe. "A universe is simply a model of the Universe" (p.11). In this sense one speaks of the Pythagorean universe, of the Medieval universe or of the scientific universe of the twentieth century. In this perspective, the role of modern cosmology is beautifully visible: on the one hand, cosmology endeavors to put the pieces, collected by other sciences, together in order to see a global picture of the jigsaw puzzle; on the other side, it does this in a very selective manner, and consequently, the global picture is highly polarized. The polarization in question is called by Harrison the containment principle which states: "The physical universe contains everything that is physical, and nothing else" (p. 100). These are not philosophical likes or dislikes of cosmologists that induce 121
them to put outside the realm of comsmological science everything which is non-physical; this strategy belongs to the very essence of experimental science. Harrison's containment principle is not a "declaration of an outrageous philosophy" (ibid.) but a purely methodological principle. When we use the above strategy, it works smoothly. When we begin to reflect upon what we are doing, this starts to produce paradoxes. One of them in Harrison's terminology, and may be reduced to the bears the name "containment riddle", "where in a universe can be found the following question: cosmologist conceiving that universe?" (p. 115) If the universe contained not only the body of the cosmologist but also his mind, the universe would contain the cosmologist whose mind would contain the universe,... and so on ad infinitum; a typical multi-mirror situation. The cosmologist inhabits the Universe but he is clearly outside the universe he has created. As if on the margin the author makes the following remark: "Those people who cannot agree with this proposition, and claim that life and mind are no more than a collective dance of atoms, must answer the containment riddle" (p. 116). containment The principle proves to be a useful methodological tool in analyzing other philosophical problems, the creation problem. Here also one should distinguish I.e., the concepts "Creation" and "creation". Creation (with a capital C) is the justification for the existence of the Universe whereas creation attempts to explain the origin of matter in an already existing universe (e.g. creation of particles in the steady-state world model). Of course, because of the containment principle in cosmology, only the question of the creation can appear. On the other hand, however, if somebody invokes a cosmological model presenting an infinitely old universe (e.g. the steady-state model or EddingtonLemaitre model) in order to discard the Creation doctrine, somebody commits a logical error. No model of the universe can explain the existence of the Universe. "An infinite span of time" - writes Harrison - "has to be created in the same way as a finite span of time." (p. 110) One should not conclude, however, that "The Science of the Universe" is a philosophical monograph. First of all, it and it ought to be read as, a good popularization of is, scientific cosmology, and in every good popularization of science there must be a touch of philosophy. Methodological distinctions are indispensable in order not to confuse science and philosophy but each scientist is a human being who asks both questions and Questions. Michael
122
Heller