J. Brit. Astron. Assoc., 107, 1, 1997, p.43

The Lighter Side of Gravity

by Jayant V. Narlikar

Cambridge University Press, 1996. ISBN 0-521-55009-2 (hbk.), 0-521-56565-0 (pbk). Pp xii + 217, £24.95/£9.95.

reviewed by Quentin Stanley

The Lighter Side of Gravity is not a set of anecdotes as its title and cover may indicate. It is quite a comprehensive text taking the reader from the question of why things move to the results of COBE and the search for dark matter.

In the path Narlikar treads for us we are taken in small jumps, where the reader has to fill in the gaps. He is not so cruel as to leave no indication of the deductions required, but rather gives a starting point, a result, and a clue of how we arrived. This method Narlikar carries out well as he does not forget the needs of his readers. It makes the book an ideal text for the keen A-Level student or undergraduate to build their reasoning. For the more advanced scholar it provides a nice refreshing recollection of details.

The book covers a good range of topics which each treat a different aspect of gravitational effect and how our understanding of it leads to various deductions about the Universe around us. Starting with the early history of the interpretation of motion, it builds quickly into the planetary laws and some of the controversy raised. Further, we go on to the realisation that gravitational contraction is not sufficient for solar energy (Kelvin–Helmholtz) and nuclear fusion is brought into our equations. By chapter 5 we are looking at Einstein's approach against Newton's. The following chapter then uses the two formalisms and provides a comparative study. Soon we get into the favourite of Black and White Holes and their properties. (The question of their existence takes a much smaller rôle in this edition than in the first edition of 1982.) By the end of the book we have new chapters looking at the Grand Unification Theory and the creation of matter.

In total I found the book a refreshing read. I believe it is not ideal for the short attention span investigation, which I feel too many modern publishers prefer, but the rewards await those who concentrate on its contents.