Australian astronomer Bryan Gaensler lands squarely in the "Goldilocks zone"--where in-depth science and layperson readability meet--with his first book, Extreme Cosmos. He explores objects as exotic as supermassive black holes and neutron stars, managing to find examples so extreme as to make other parts of the heavens look mundane. Neutron stars are especially fascinating--remnants of post-supernova stars, these balls of neutrons are just 15 miles wide with densities in the hundreds of millions of tons per cubic centimeter; one of them has been found with a rotation speed of 716 times per second.
Gaensler acknowledges that these numbers can be so far beyond everyday experience they become meaningless. His solution is the frequent use of analogies, simple enough to explain the grandest of concepts without feeling forced or condescending. "Astronomy is a dynamic and burgeoning field," he points out. "New discoveries are made on a daily basis, and records are invariably shattered." There are so many of these that many record-holding astronomical objects are named with seemingly inane strings of letters and numbers. (For example, the rapidly spinning neutron star is "PSR J1748-2446ad.") They are relatively fresh finds, and this book will surely need updating in the future.
Gaensler displays his specimens like an interstellar curator, careful to explain the context and measurements used in determining each record. His lifelong passion for astronomy is evident in his contagiously energetic prose. At times he turns from scientific curator to giddy schoolboy, as though dragging the reader through galactic galleries and exclaiming the awesomeness of every exhibit. Gaensler toes the fine line between his "professor" and "pupil" voices with care, creating an intellectual foray that readers with even passing interests in astronomy will find enjoyable. --Tobias Mutter, freelance reviewer