Origins: How the Planets, Stars, Galaxies, and the Universe Began

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.