Ice-nine

Ice-nine is a fictional material that appears in Kurt Vonnegut's 1963 novel Cat's Cradle. Ice-nine is described as a polymorph of ice which instead of melting at 0 °C (32 °F), melts at 45.8 °C (114.4 °F). When ice-nine comes into contact with liquid water below 45.8 °C, it acts as a seed crystal and causes the solidification of the entire body of water, which quickly crystallizes as more ice-nine. As people are mostly water, ice-nine kills nearly instantly when ingested or brought into contact with soft tissues exposed to the bloodstream, such as the eyes or tongue.

In the story, it is invented by Dr. Felix Hoenikker^[1] and developed by the Manhattan Project in order for the Marines to no longer need to deal with mud. The project is abandoned when it becomes clear that any quantity of it would have the power to destroy all life on Earth. In the novel's climax, the Earth's oceans are accidentally frozen solid by ice-nine, prompting a doomsday scenario.

Vonnegut encountered the idea of ice-nine while working at General Electric. He attributes the idea of ice-nine to his brother Bernard, who was researching the formation of ice crystals in the atmosphere.^[2] A later account of the events attributes the idea to the chemist Irving Langmuir, who devised the concept while helping H.G. Wells conceive ideas for stories. Vonnegut decided to adapt the idea into a story after Langmuir's death in 1957.^[3]