Science writer Lightman’s premise is as follows: in 1905, young Albert Einstein dreamed repeatedly about time as he worked on his paper “On the Electrodynamics of Moving Bodies” and made creeping progress on his special theory of relativity. Each dream reveals "one of the many possible natures of time.'' Lightman presents these (entirely fictional) dreams as a collection of poetic vignettes. Small enough to read in an afternoon, but easy to wander in and out of. Unusual and utterly delightful.