Arthur Clarke is the high lama of science fiction and non-fiction; as an astrophysicist he wrote The Exploration of Space; with a Wellsian imagination he concocted Childhood's End. The articles collected here, mostly reprints from Holiday. Horizon and Playboy, are way-out entertainments, fun-list futuramas, crisp; clever explanations of frequently inexplicable realms such as relativity, precognition, historical recalls, time-travel and multi-dimensional Euclidean space. The future, says Mr. Clarke, will be fantastic, and he makes good his claim: "conventional" jets operating at 200 miles an hour; floating-on-air cars, without wheels, using "ground effect"; portable gravity-control units strapped round the shoulders, ready for take-off when terrestrial pursuits get dull; Renaissance analogies to the coming up discovery of an extant or extinct Martian civilization; a radio-telescope break-through whereby we contact "intelligence" outside the solar system; the end of material problems and materialism with the replicator machine. Unfortunately, Mr. Clarke is neither a Goethe nor a Shakespeare, and these "mid-numbing" contemplations of endless eons, endless knowledge, eventually read like so much avant garde advertising copy. Further, he systematizes nothing; there are no socio-cultural parallels drawn; man, as we've known him, vanishes completely in this gala inquiry into the limits of the possible.