The Curvature of Spacetime: Newton,
Einstein, and Gravitation
By Harald Fritzsch
Tr. Karin Heusch
New York, Columbia University Press, 2002
320 pp. Illus. b/w,
ISBN 0-231-11820-1
Reviewed by Robert Pepperell
pepperell@ntlworld.com
Harald Fritzsch has produced a book intended
to: "contribute to the incorporation of Einsteins ideas
into our more general culture, and not just into the experts
domain of knowledge" (Preface). Despite its reputation for incomprehensibility
many of the ideas generated by relativity theory are beautifully simple,
even though they stretch the credulity of our intuitive understanding
of nature.
Using the format of an imaginary three-way dialogue between Einstein,
Newton and a fictional contemporary physicist, Adrian Haller, the
book discusses gravitation according to the general theory of relativity.
The dramatic tension in the debate lies between Newtons view
of the universe in which time, space and matter are independent and
absolute properties of nature and Einsteins view that these
are each interdependent and relative properties of a universal spacetime
continuum. The Haller character intervenes to update his companions
on the latest data and theories from current physical research. Einstein
tries to explain his ideas to a skeptical Newton using an array of
thought experiments, logical arguments, intuitive insights and analogies,
many of which are graphically illustrated in the book.
On many different levels this is a staggering read. First the sheer
scales involved in relativity theory, sub-atomic and astrophysics,
both micro- and macroscopic, are unimaginable. We are dealing with
measurements that are, at one extreme, billionths of billionths of
a centimeter small and at the other trillions of miles long. There
are immensities of heat, depths of coldness, magnitudes of energy,
and speeds so colossal that one is left simply staring at numbers
trying to form some image that refuses to materialize. On another
level one is left in awe of the achievement of both Newton and Einstein
and their capacities for perseverance and original thought. Finally
there is the semi-religious sense of ones own transient existence
combined with the almost comforting sense of continuity with a universe
that transcends life itself. It is little wonder that Einstein made
such frequent reference to God, as the quotes included in this volume
bear witness.
There have been many admirable attempts to bring Einsteins ideas
to a wider public, and Im sure The Curvature of Spacetime
makes a contribution to that process. It is by no means the easiest
of such books to read, particularly for one with no scientific training
and very little mathematical fluency. But I found I was able to follow
most of what was discussed even if I could not hold it all together
long enough to see grand picture. In this respect one can at least
take consolation from the example of Einsteins humility when
he writes:
"If I have learned one thing from all the pondering that has
accompanied me through my long life, it is this: we are further removed
from a deep insight into the elementary processes in our world than
most of our contemporaries would believe." (p. 36).