Nuclear weapons have a mysterious quality. Their power is measured in plainly visible blast pressure and thermal energy common to many weapons, but also invisible yet equally destructive radiation and electromagnetic pulse. Between 1945 and 1992, the United States conducted 1,032 nuclear tests seeking to get the measure of these enigmatic weapons. Many of these tests would be today be considered unnecessary, overly dangerous and just plain bizarre. These tests, undertaken on the atomic frontier, gathered much information about these weapons—enough to cease actual use testing—yet scarred the land and left many Americans with long-term health problems.