Death and serious injury from dark matter

Abstract Macroscopic dark matter (macros) refers to a class of dark matter candidates that scatter elastically off of ordinary matter with a large geometric cross-section. A wide range of macro masses M X and cross-sections σ X remain unprobed. We show that over a wide region within the unexplored parameter space, collisions of a macro with a human body would result in serious injury or death. We use the absence of such unexplained impacts with a well-monitored subset of the human population to exclude a region bounded by σ X > 10 − 8 − 10 − 7 cm2 and M X 50 kg. Our results open a new window on dark matter: the human body as a dark matter detector.