Smoke detectors are antimatter-using devices that were invented in 2203 when Gashlit S'vrthuya said that there was too much Nvoksite in the atmosphere. They were supposedly invented by the civilisation of the Sp'rsikk in the Outer Star Bubble 2-10S+5504 1,000 years before that, but there is no proof for it. V'lag H'lghaimrn re-invented the wheel in 22938 so that Gosvol would not need to spend all his nvoksite on smoke detectors.