Harry Clement Stubbs, 81, a science fiction writer whose most famous novel was "Mission of Gravity" under the pseudonym Hal Clement, died Oct. 29 of natural causes in Milton, Mass.
Known for pairing information with imagination, Stubbs was a leader in the world-building science fiction genre -- in which writers employ plausible science to create a fictional world.
"Mission of Gravity," first serialized in Astounding Science Fiction [now Analog] magazine in 1953, was set on a disc-like planet called Mesklin. The planet had a gravity 700 times that of Earth, and a 6-inch fall could be fatal to natives.
Born in Somerville, Mass., and reared in Boston, Stubbs became intrigued with science and science fiction in 1930 by a Buck Rogers comic strip. Seeking explanations, he checked out an astronomy book and Jules Verne's novel "Trip to the Moon" from the public library. He went on to earn a bachelor's in astronomy from Harvard, and after serving as Army Air Forces bomber pilot toward the end of World War II, obtained a master's in education from Boston University and a master's in chemistry from Simmons College.
Stubbs, who taught high school science for 40 years, published about 18 Hal Clement science fiction books and numerous short stories, as well as scholarly science articles under his own name.