Understanding The Universe

There is hardly any field of human endeavour which is more fundamental than the study of our surroundings. We have always wanted to learn what was behind our horizon, beyond the next mountain, on the other side of the ocean, on the next planet, at the end of the Universe. We have come a long way since our early ancestors gazed upon the sky in amazement. Giant optical and radio telescopes now allow us to "see" the early epochs of the Universe, revealing phenomena beyond our comprehension. Spacecrafts with on-board astronomical instrumentation circle the Earth and fly to the limits of the Solar System, providing invaluable new information about nearby and distant objects. Many people have the intuitive feeling that it is "easier and better" to study the Universe from above the Earth's atmosphere.

For the last eighteen years, I have been teaching an introductory course in as­ trophysics. The course is intended for nonscience majors satisfying a general education requirement in natural science. It is a physics course with applications in astronomy. The only prerequisite is the high school mathematics required for ad­ mission to the university. For a number of years, I used an astronomy text, which I supplemented with lecture notes on physics. There are many good astronomy texts available, but this was not a satisfactory state of affairs, since the course is a physics course. The students needed a physics text that focused on astronomical applications.

Who has not gazed with wonder at the night sky, especially from a dark site far away from city lights? The great canopy of stars stretching overhead suggests that our world is part of a vastly larger cosmos. But how large is it? Where do we fit in? And how did it all begin? These questions have puzzled stargazers for thousands of years, and the search for answers helped spark the great advances of the scientific revolution in the 16th and 17th centuries. But only in our own time has the full picture of the true immensity, variety, and surpassing strangeness of the Universe come into focus.

By the star physicist and author of multiple #1 Sunday Times bestsellers, a major and definitive narrative work on black holes and how they can help us understand the universe.