A kind of forerunner to "Paths to Otherwhere." Possibly the first novel to deal realistically with parallel universes. ( )

A neat little transporter novel. The gimmick is that when you transport you end up in a parallel universe whose similarity to yours is governed by the distance you teleport. The greater the distance, the greater the difference. So the central protagonist transports and begins to notice subtle differences, and Brunner has fun with that. Brunner does some infodumping with Transfinite math to explain the proceedings, and he's done (which is a characteristic Brunner MO). Could have been something great if it were longer, but it's fun as it is. ( )

http://eruditionis.blogspot.com/2007/... ( )