Here we are, two fast-talking women on estrogen, staring at a wall of live mitochondria from the brain of a rat. Mitochondria are cellular energy generators of unfathomably tiny size, but these are vivid and big because they were hit with dye in a petri dish and enlarged for projection purposes. They’re winking and zooming, like shooting stars. “Oh, my God,” Roberta Diaz Brinton said. “Look at that one. I love these. I love shooting mitochondria.”