Review by Stephen Coulson
We are made of stars. The atoms forming everything on Earth were forged in the crucible of long-dead stars. But only very recently have scientists appreciated how events on Earth are influenced from the farthest reaches of the galaxy and beyond. Over 64 tons of material, the equivalent of about 12 elephants, enters the atmosphere every day-4,400 elephants a year, quite a herd. Most of this falls as dust particles from comets and asteroids, which reside mainly in the Oort Cloud– a massive graveyard of icy bodies in the coldest depths of the solar system, beyond Pluto. Some of these bodies are very large indeed. Under the gravitational pull of the galaxy, on occasion they can hit the Earth’s surface, causing widespread destruction and leading to the extinction of whole species, such as dinosaurs. In a whistle-stop tour of modern physics, Randall attempts to link the extinction of the dinosaurs to the latest thinking on the source of the greatest mass in the universe–dark matter. An ambitious undertaking that contains a few minor mistakes, but is still a fascinating read and as convincing as the arguments for dark matter itself.