EINSTEIN'S DREAMS, by Alan Lightman

ALBERT EINSTEIN, in one of the many remarks that have endeared him to writers seeking epigrams, said that what really interested him was whether God had any choice in how to create the world. Of all the attributes God might have chosen for the universe, surely among the most poignant and mysterious is time. To a physicist time is what a clock measures. To most of the rest of us it is irregular -- like a current, sometimes swift, sometimes slow, carrying us along. Despite the efforts of the Einsteins and Newtons of the world, the dichotomy between objective and subjective time still remains.

These two facets of the temporal have rarely been as slickly and delightfully joined as they are in this tiny novel -- which reads like a collection of playful fables -- about time and its inhabitants. "Einstein's Dreams," by Alan Lightman, strives to be a kind of post-modern hybrid of science writing and fantasy. It stands partly in the tradition of a series of books written in the 1940's by George Gamow, an astrophysicist and a founder of Big Bang cosmology. Gamow's tales are about a bank clerk named C. G. H. Tompkins, whose dreams and adventures involve the wonders of relativity and quantum mechanics. But Mr. Lightman, a physicist with a decidedly poetic bent, also owes much to fabulists like Italo Calvino, whose book "Invisible Cities" seems to be the model for "Einstein's Dreams."

Mr. Lightman's conceit is that on the nights leading up to Einstein's formulation of the special theory of relativity -- which forever transformed our notions of time -- the young scientist, then a 26-year-old patent clerk in Bern, Switzerland, dreamed about time, conjuring up notion after notion of how God might have chosen to construct things.

On each frenzied night a new dreamlike, cartoony picture of Bern lurches into motion, the lives of shopkeepers and lovers arranged and rearranged to adapt to the temporal exigencies and opportunities of each new vision. In one dream, a woman swept back into the past by a stray current of time huddles in a doorway trying not to kick up dust that could alter history. In another vision, time moves in a circle and history keeps repeating itself; some unhappy people, sensing they are doomed to endless repetitions of their mistakes, fill the night with their moans. In still another dream, cause and effect become disjointed: a woman's heart leaps and a week later she meets a suitor.

Mr. Lightman spins these fantasies with spare poetic power, emotional intensity and ironic wit, although he often veers toward sentimentality. If time is a burden, he implies -- too often -- the attempt to escape it is an even deadlier burden. In his scheme, the only happy people are those who have surrendered to the moment. Thus the scientists are always grumpy, and the artists are always joyous. In the acausal world, he gushes, "each kiss is a kiss of immediacy."

There is a sly method to this madness, though; many of these dreams are based on real physics. Playing off the relativistic idea that people in motion would appear to age more slowly, Mr. Lightman offers a caricature of special relativity -- a dream in which all the houses and offices are on wheels, constantly zooming around the streets (with advanced collision-avoidance systems). In another fantasy, people go to the center of time in order to freeze their lovers or their children in century-long embraces; this place is clearly reminiscent of a black hole, where, theoretically, gravity would stop time.

Mr. Lightman's vision of a woman's heart leaping before she has met the man she will fall for is likewise based in science; acausality is a feature of quantum mechanics, a revolution 70 years old and still snowballing through physics. And even the fantasy of a world where time has three dimensions instead of one, where every moment branches into three futures, has a scientific antecedent; one view of quantum theory, known as the "many worlds" interpretation, has been espoused by Stephen Hawking, among other physicists.

It's no wonder that the fictional Einstein is tired enough to spend most of this book sleeping. He dreams not of many worlds, but rather of the many exhausting facets of our own.