Origins: how the planets, stars, galaxies, and the universe began

Abstract

The Series This new series is aimed at the same people as the Practical Astronomy Series – in general, active amateur astronomers. However, it is also appropriate to a wider audience of astronomically-informed readers. Because optical astronomy is a science that is rather at the mercy of the weather, all amateur astronomers inevitably have periods when observing is impossible. At such times they tend to read books about astronomy and related subjects. The Astronomers’ Universe Series begins by assuming an appropriate level of knowledge. Basic information about the distance, the solar system, galaxies, etc. is not part of these books, which can take a basic understanding of this as their starting point. The series is differentiated from popular science series (such as Springer’s Copernicus books) by a strong design image which will attract active amateur astronomers, but will also appeal to "armchair astronomers" (or cosmologists) and other readers who already have the necessary background knowledge. The Book This book is about the origin questions – the questions of how (1) the planets, (2) the stars, (3) the galaxies, and (4) the universe itself were formed. These are the biggest questions in astronomy, and in the last decade, there has been a revolution in observational astronomy which has meant that we are very close to answering three of the four big questions. It is therefore a propitious time for this book. In the last decade, there has been a revolution in observational astronomy, which has meant that we are very close to answering three of the four big ‘origin questions’, of how the planets, stars, galaxies, and the universe itself were formed. As recently as 1995 we knew of only one planetary system: our own. Now we know of over a hundred, and this knowledge has helped to reveal how planetary systems form. In this same decade, new types of telescope have allowed us to penetrate through clouds of interstellar dust to see the first moments in the life of a star, and also to see directly (not infer) what galaxies looked like thirteen billion years ago, only a billion years after the Big Bang. Because of this new knowledge, we now have provisional answers to the second and third origin question. The final question is the one we can’t yet answer, but even here there have been big steps towards an answer. Within the last four years, astronomers have discovered that the universe is geometrically flat and that its expansion is accelerating, fuelled by a mysterious dark energy. This revolution in our observational knowledge of the universe – including the first precise measurements of its age and matter and energy content - has been vital groundwork for new ideas about its origin, including the possibility that the universe originated in a larger `meta-universe’. Origin Questions describes, at an understandable and basically non-mathematical level, the origin questions and the recent steps that have been taken towards answering them.