What sets Dyson apart among an elite group of scientists is the conscience and compassion he brings to his work. One of his specialties is in the field of adaptive optics, work with mirrors that can, in theory, allow a ground-based telescope to see objects as clearly in the sky as a space-based telescope. Dyson understood the dark side to adaptive optics -- that the technology used peacefully by astronomers could be used by military to focus laser beams on satellites, aircraft and other targets. Before beginning his work on the optics, Dyson studied both the peaceful and the military applications and determined that the latter death ray scenario was more the stuff of science fiction than reality. To this day, Dyson's work is enabling astronomers to make successful observations.