Phillip's Astronomy Encyclopedia

The progress of astronomy – or, more precisely, astrophysics – over the past century, and particularly the past generation, is not easily pigeon-holed. On the one hand, profound truths have tumbled abundantly from the sky. Here are four diverse examples: 1. Our universe began some 14 billion years ago in a single cataclysmic event called the Big Bang. 2. Galaxies reside mainly in huge weblike ensembles. 3. Our neighbouring planets and their satellites come in a bewildering variety. 4. Earth itself is threatened (at least within politicians’ horizons) by impacts from mean-spirited asteroids or comets. On the other hand, ordinary citizens may well feel that astronomers are a confused lot and that they are farther away than ever from understanding how the universe is put together and how it works. For example, ‘yesterday’ we were told the universe is expanding as a consequence of the Big Bang; ‘today’ we are told it is accelerating due to some mysterious and possibly unrelated force. It doesn’t help that the media dine exclusively on ‘gee-whiz’ results, many of them contradictory and too often reported without historical context. I can’t help but savour the pre-1960s era, before quasars and pulsars were discovered, when we naïvely envisioned a simple, orderly universe understandable in everyday terms.