Anathem
Neal Stephenson2008

Erasmas, "Razï", is a young avout living in the Concent, a sanctuary for mathematicians, scientists, and philosophers. Three times during history's darkest epochs, violence has invaded and devastated the cloistered community. Yet the avout have always managed to adapt in the wake of catastrophe.

But they now prepare to open the Concentïs gates to the outside world, in celebration of a once-a-decade rite. Suddenly, Erasmas finds himself a major player in a drama that will determine the future of his world as he sets out on an extraordinary odyssey that will carry him to the most dangerous, inhospitable corners of the planets and beyond.