AIDS is not caused by HIV. Coal and oil are not fossil fuels. Distributing more guns reduces crime. These ideas make headlines, but most educated people scoff at them. Yet some of science's most important concepts - from gravity to evolution - have surfaced from the pool of crazy ideas. Here, a physicist with an affinity for odd ideas applied his open mind to nine controversial propositions on topical subjects. Some, it turns out, are considerably lower on the cuckoo scale than others. Anyone interested in unorthodox ideas should enjoy this book. And, as a fun way of learning how to think like a scientist, it also has educational value.