A few months later when Maiman built the first ruby laser, his own company, Hughes Aircraft, began working on laser weapons. Soon, various branches of the military-army, navy, and air force-gave money to several other companies to develop such weapons. Between 1962 and 1968 the army alone spent almost $9 million on laser research.

But could such death rays actually be built? The answer, at least at that time, was no. Scientists found that lasers did indeed produce very concentrated beams of light. But building the kinds of weapons the military wanted turned out to be much more difficult than everyone had figured. "So far lasers have been found to make poor weapons," says Breck Hitz, "and many scientists believe that engineering complexities and the laws of physics may prevent them from ever being particularly useful for this purpose."4 Nevertheless some researchers are more optimistic...