What is "spome"

A '''spome ''' is any hypothetical system closed with respect to matter and open with respect to energy capable of sustaining human life indefinitely. The term was coined in 1966 by Isaac Asimov in a paper entitled "There’s No Place Like Spome", published in Atmosphere in Space Cabins and Closed Environments and originally presented as a paper to the American Chemical Society on September 13, 1965. Asimov himself declared his coined word to be uneuphonious (not pleasant to the ear), and defined it as being a portmanteau of the two words "space home".