The lectures in the sixth edition focus on our cosmic origin, as well as the fact that gravity, the most familiar and important force in the universe’s evolution, continues to pose some challenging questions.

The fifth edition explores issues such as cosmic rays and anti-matter, the evolution of galaxies and the role played by black holes, the exploration of the Solar System, and the detection of gravitational waves.

The fourth edition considers the enigmatic nature of dark matter and the most recent attempts to detect it with large underground instruments, the expansion of the universe, as well as recent research with particle accelerators.

The discovery of the earliest galaxies, the search for signs of life in the universe, the long-term stability of planetary systems and the study of starquakes are some of the issues examined in the third edition.

How many planets similar to Earth are orbiting other stars? The lectures in the second edition explore questions such as the search for life in other worlds, the expansion of the universe, neutron stars, and clusters of galaxies.

Why, at some point some 13 billion years ago, did a tiny, hot universe begin expanding in a Big Bang? The birth of the universe, as well as the formation of stars and planets, are explored in the first edition.