Hypnos comes from the name of his Latin counterpart, Somnus. (in- "not" + somnus "sleep"), as well as a few less-common words such as "somnolent", meaning sleepy or tending to cause sleep and hypersomnia meaning excessive sleep, which can be caused by many conditions (known as secondary hypersomnia) or a rare sleep disorder causing excessive sleep with unknown cause, called Idiopathic Hypersomnia. 3D model of "Bronze head of Hypnos" via laser scan of a cast of British Museum's bronze. Hypnos In Greek mythology, Hypnos (; , "sleep") is the personification of sleep; the Roman equivalent is known as Somnus. In the
Greek mythology in popular culture elements tantalum and niobium are always found together in nature, and have been named after the King Tantalus and his daughter Niobe. The element promethium also draws its name from Greek mythology, as does titanium, which was named after the titans who in mythology were locked away far underground, which reflected the difficulty of extracting titanium from ore. The U.S. Apollo Space Program to take astronauts to the moon, was named after Apollo, based the god's ability as an archer to hit his target and being the god of light and knowledge. Oceanographer Jacques-Yves Cousteau named his research ship, a