Physics, the Human
Adventure: From Copernicus to
Einstein and Beyond
Gerald Holton and
Stephen G. Brush
Rutgers University Press, New
Brunswick, New Jersey and London, 2001, ISBN 0-8135-2908-5
Physics, the Human Adventure is the third paperback edition of Introduction to Concepts and Theories in Physical Science which appeared first in 1952. Primarily a student text, it is monumental in its approach, weighing in at 582 pages (including appendices), but within, it has a lightness of touch that would calm and reassure the most nervous of students. It divides the material into friendly, bite-sized sections and chapters, with a two column per page format liberally sprinkled with portraits of famous scientists, that exudes the feeling of a cosy armchair narrative. But this book is no walk in the park. As its title suggests it is an adventure, and the authors, rightly in my view, make no compromise in their treatment of the material, save in their effort to communicate accurately, lucidly and thoughtfully. It is this latter characteristic which marks out this book from the herd. In the authors own words they seek to teach Physics “by showing how its basic principles and results were established” and “how that science is a true part of our developing cultural heritage”. The historical, philosophical and cultural aspects of science are thus seamlessly integrated into the text, together with enough mathematical gravitas to feed the flow of scientific narrative.
The first introductory sections, chapters 1 to 5, introduce the reader by way of a review of ancient Astronomy up to the time of Galileo. The accent is historical and philosophical and lays the groundwork for the material that follows. The section ends with an essay on Science and Freedom (Sect. 5.4), which stresses that freedom to debate and publish is the lifeblood of Science.
The next two sections (Chaps. 6 to 11) cover motion. A touch of humour at the start is well placed, and attributing Descartes’ habit of prolonged meditation as down to his staying in bed late on account of poor health as a child, whether true or not, adds a human image to the subject matter.
Questioning is important and the many sections of the book carry both questions to consider as well as problems to be solved. Further information is available on an excellent website which readers may consult. Many of the questions are refreshingly outside the usual conventional format. Particularly notable was the question inviting readers to probe the relationship between Mathematics and physical events (Section 6.2). The section includes a careful analysis of equations in Physics and their limitations; the importance of an unseen “text” which is not overtly apparent from the form of equations alone. Some minor criticisms here: the subject of dimensionality of equations in Physics is relegated to a footnote (p 69) – I think it deserves a more prominent place in the main text. The problem, of course, is that in a book of close to 600 pages if you put something in, what do you remove? One puzzling error is the mention in the section on gravitational lenses (p 482) of the partial image of an “Einstein ring” lens on the front book cover, which is not in fact shown. Also the reference to Dennis Walsh as the discoverer of the first gravitational lens should include his two colleagues Bob Carswell and Ray Weymann, who were co-discoverers.
The authors move from motion to what they refer to under the general heading of: “Structure and Method in Physical Science” (Chapters 12 to 14), which represents a useful introduction to Philosophy of Science. Again liberally sprinkled with discussion questions – I particularly like the first two points of problem 14.6 (p 198): What is meant in science by the statement: a) Atoms exist b) The ether does not exist.
Stressing the thematic accent of Physics, there is an important section on conservation laws of mass, momentum and energy, (Chapters 15 to 18), which also provide a neat framework leading on to Atomic theory and Chemistry which covers chapters 19 to 22. The authors always have their feet on the ground. Section 20.6 on Dalton’s “Rule of Simplicity” introduces what can only be described as a monumental failure by Dalton who tried to explain how the structure of common stable compounds could be inferred using a rule of “greatest simplicity”. The importance of this section is not just to give Science its human face – even the great Dalton can get it wrong – but to highlight the jagged path of progress – two steps forward, one step back – which is not usually revealed in textbooks.
The main thrust of any student text is explanation of the subject matter but Holton and Brush inject just the right note of caution and scepticism. “We must be on guard against conceiving of too literal a model for molecules as little spheres” (Chap. 22.7, p 328), and a clear visualizable model that is not logically consistent always loses out to a useful principle (Einstein’s principle of the constancy of the speed of light in a vacuum) - in spite of the fact that the latter flies in the face of intuition (Chap. 25.3, p 377).
The last section of the book brings Physics up to date and together with a useful set of appendices ends with the “Anthropic Principle” (Chap. 32.6) and a final chapter (33) on “themata” in Science. These latter cover presuppositions, ideas and even intuition. Sometimes intuition works sometimes it does not. Holton and Brush keep their readers on their toes right to the end – the last paragraph (p 530) stresses the numerous unsolved problems yet to be confronted. This challenge is what makes Science an adventure.
Nigel Sanitt