Preface to Second Edition
In the three years since the first edition of this book was finalized, the field of cos-
mology has seen many important developments, mainly due to new observations with
superior instruments such as the Hubble Space Telescope and the ground-based Keck
telescope and many others. Thus a second edition has become necessary in order to
provide students and other readers with a useful and up to date textbook and refer-
ence book.
At the same time I could balance the presentation with material which was not
adequately covered before—there I am in debt to many readers. Also, the inevitable
number of misprints, errors and unclear formulations, typical of a first edition, could
be corrected. I am especially indebted to Kimmo Kainulainen who served as my course
assistant one semester, and who worked through the book and the problems thor-
oughly, resulting in a very long list of corrigenda. A similar shorter list was also dressed
by George Smoot and a student of his. It still worries me that the errors found by
George had been found neither by Kimmo nor by myself, thus statistics tells me that
some errors still will remain undetected.
For new pictorial material I am indebted to Wes Colley at Princeton, Carlos Frenk
in Durham, Charles Lineweaver in Strasbourg, Jukka Nevalainen in Helsinki, Subir
Sarkar in Oxford, and George Smoot in Berkeley. I am thankful to the Academie des
Sciences for an invitation to Paris where I could visit the Observatory of Paris-Meudon
and profit from discussions with S. Bonazzola and Brandon Carter.
Several of my students have contributed in various ways: by misunderstandings,
indicating the need for better explanations, by their enthusiasm for the subject, and by
technical help, in particular S. M. Harun-or-Rashid. My youngest grandchild Adrian
(not yet 3) has showed a vivid interest for supernova bangs, as demonstrated by an
X-ray image of the Cassiopeia A remnant. Thus the future of the subject is bright.
Matts Roos