Alan Lightman

In Alan Lightman's new novel, "Ghost," you're never quite sure what to believe.

But Lightman, a theoretical physicist who a decade ago gave us the bestselling novel "Einstein's Dreams," knows what he's up to. He wants to explore the edges of belief — both religious and scientific.

David, his protagonist, works at a funeral home, and one day he sees something — a ghostly vapor — out of the corner of his eye. Unable to explain it, David's rational world view is shaken.

It's a bold premise for a scientist.

This hour, On Point: physicist and novelist Alan Lightman on faith and reason.Guest:

Alan Lightman, author of the new novel "Ghost." He's the best-selling author of the book "Einstein's Dreams" and teaches at MIT.