Anathem by Neal Stephenson

Novelist Neal Stephenson Once Again Proves He's the King of the Worlds: "Anathem documents a civilization split between two cultures: an indulgent Saecular general population (hooked on casinos, shopping in megastores, trashing the environment—sound familiar?) and the super-educated cohort known as the avout, who live a monastic existence defined by intellectual activity and circumscribed rituals called 'auts.' Freed from the pressures of pedestrian life, the avout view time differently. Their society—the 'mathic' world—is clustered in walled-off areas known as concents built around giant clocks designed to last for centuries. The avout are separated into four groups, distinguished by the amount of time they are isolated from the outside world and each other"