This is a condition, which is considered to be mythological to some. The condition causes the brain, along with the rest of the head, to explode. This is caused by concentrating. This condition is often referred to as H.C.E., and often leaves the audience of an H.C.E. attack under suspicion of murder.
Gerald and Larry were poking cow patties when Gerald mentioned the time-space continuum. Shortly after, Larry's head exploded due to his acute Hyper Cerebral Electrosis, and Gerald was left as the prime suspect for his murder.