Question about Brian Greene's wormhole illustration in "Fabirc of the Cosmos" I'm currently watching this show on NOVA narrated by Brian Greene called "The Fabric of the Cosmos". In the first episode, he talks about space and the fact that it has properties. In the second episode, he talks about time and how the rate at which time passes is affected by motion. He uses some brilliant illustrations to describe each topic, but there's one thing that seemed a bit off on his explanation. First of all, he debunked this illusion that time is a constant flow. He said it's more like a series of snapshots that occupy specific points in spacetime. And if you were to plot all events on the spacetime grid (conveniently shaped like a loaf of bread in his illustration), you could cut a slice down the width of the loaf. All events along that line make up what is called a "now-slice", because it contains everything that is happening "now" (at that moment in time) experienced by each observer in all locations. This was followed by an illustration of general relativity that I don't feel the need to explain. He goes on to talk about wormholes, saying that they connect two points in spacetime - two different "nows". But in his illustration, he walks through the worm hole and meets himself. And then talks about The Grandfather paradox, and the fact that we don't see people popping in from different times. However, if you were to step through a wormhole and meet yourself at a given time, wouldn't that create a new point in spacetime? Because, the time-traveling you wasn't in the past before you time-traveled. You created that new point in spacetime the moment you stepped through the wormhole. Instead, when you step through the wormhole, wouldn't you find yourself in a location you were in sometime in the past, doing something you did sometime in the past, experiencing the same sensory input and knowledge that you had in the past? Would you even remember that you had stepped through a wormhole? You'd be re-living a "now" from the past... so your experience would have to be exactly that of the past. Right? That way, there's no paradox to deal with. And new points in spacetime aren't created based on your future decision to take a course of action. Though, I don't see how it's possible for two points in spacetime to connect.