A subject whose time has come

IN “Chronos: How Time Shapes Our Universe” (translated from the French by Glenn Burney; Thunder’s Mouth Press: 192 pp., $24), Etienne Klein, a physics professor and philosopher of science at the Ecole Centrale de Paris, has written a mind-bending meditation on a subject in which, his publisher assures us, he is “one of the world’s foremost specialists.”

This is a formidable claim, given that time is the snarliest topic in physics. It is the ultimate intangible, yet -- ever since Galileo introduced it as a physical variable to help explain why a pound of feathers and a ton of lead, dropped in a vacuum, will hit the ground simultaneously (Don’t ask, just get out of the way) -- it is absolutely essential to the workings of the world of matter.

If you enjoy pondering the old joke about time being nature’s way of keeping everything from happening all at once, you will revel in Klein’s stylish and thoughtful explications of a host of conundrums (Does time precede the universe? What “makes” time “pass”? Is time travel possible?) and time-related phenomena: consciousness, entropy, boredom, death and what Klein charmingly calls the “endless unfurling of the present instant.”

-- Sara Lippincott