“Spaced Out: Radical Environments of the Psychedelic Sixties” explores the crash pads, hippie communes, infinity machines and other far-out dwellings of the time period. Author Alastair Gordon, whose other works have dealt primarily with the clean modernism of airports and mid-century Hamptons homes, turned his attention to the design, architecture and visual culture of LSD-inspired era, much of which hadn’t been adequately preserved or documented until now.