Theodore (Ted) Rockwell, Member, National Academy of Engineering: We have the ability to measure very small amounts of radiation - we can actually detect single atoms as they disintegrate. So when we hear the clatter of a radiation detector, we feel that we are in danger. But the numbers we encounter from various human-made sources are quite trivial compared with the natural bath of radiation that the galaxies pour down on us as cosmic rays, and the earth and all its lovely vegetation produce, and even our water, food, and our bodies themselves are naturally radioactive.
