Otto Ramstad and Olive Bieringa — a couple collectively known as the Body Cartography — have always made environmentally inspired dances. Their new work, 1/2 Life, is born from more than five years of scientific and social exploration involving nuclear war and energy. 3-Minute Egg caught glimpses of the work and spoke with the pair about the research that went into their stage work. Performances run tonight through Saturday at the Southern Theater.