THE NEW DYNAMICS 267standing of general relativity has vastly improved, our faith in the theory has
grown, and no assured limitations on the validity of Einstein's theory have been
encountered. Yet, even on the purely classical level, no one today would claim to
have a full grasp of the rich dynamic content of the nonlinear dynamics called
general relativity.
Having completed my portrait of Einstein as the creator of general relativity.
I turn to a brief account of Einstein as its practitioner. For the present, I exclude
his work on unified field theory, a subject that will be dealt with separately in
Chapter 17.
As I prepare to write this chapter, my desk is cluttered. Obviously, copies of
Einstein's papers are at hand. In addition, I have the following books within
reach: Pauli's encyclopedia article on relativity completed in 1920 [PI] as well as
its English translation [P2], of particular interest because of the notes Pauli added
in the mid-1950s; several editions of Weyl's Raum, Zeit, Materie (including the
English translation of the fourth edition [Wl]), of importance because the vari-
ances in the different editions are helpful for an understanding of the evolution of
general relativity in the first decade after its creation; the book by North dealing
with the history of modern cosmology to 1965 [Nl]; the fine source book on cos-
mology published by the American Association of Physics Teachers [SI]; and, for
diversion, the collection of papers on cosmology assembled by Munitz [Ml], in
which Plato appears as the oldest and my friend Dennis Sciama as the youngest
contributor. Taken together, these books are an excellent guide to the decade
1915-25. They enable me to confine myself to a broad outline of this period and
to refer the reader to these readily accessible volumes for more details.
There are more books on my desk. The modern texts by Weinberg [W2] and
by Misner, Thorne, and Wheeler [M2] (affectionately known as the 'telephone
book') serve as sources of information about developments in general relativity
during the rest of Einstein's life and the years beyond. Finally, my incomplete
little library is brought up to date by a recent report of a workshop on sources and
detectors of gravitational radiation [S2], the Einstein centenary survey by Hawk-
ing and Israel [HI], the record of the centennial symposium in Princeton [W3],
and the two centenary volumes published by the International Society on General
Relativity and Gravitation [H2]. I have these five books near me for two reasons,
first to remind me that these authoritative and up-to-date reviews of recent devel-
opments free me from writing a full history of general relativity up to the present,
a task which in any event would far exceed the scope of this book and the com-
petence of its author, and second to remind me that my own understanding would
lack perspective if I failed to indicate the enormous changes that have taken place
in the ways general relativity is practiced today as compared with the way things
were in Einstein's lifetime. I do indeed intend to comment on those changes, but
will often urge my reader to consult these recent books for further particulars.