[reading: Barton Zwiebach, "A First Course in String Theory"]
So bookmark B has now caught up with bookmark A, and they have joined forces to forge on in search of some connection with the rest of the universe.
copious free time (n.): [used ironically to indicate the speaker's lack of the quantity in question] A mythical schedule slot for accomplishing tasks held to be unlikely or impossible. Sometimes used to indicate that the speaker is interested in accomplishing the task, but believes that the opportunity will not arise. "I'll implement the automatic layout stuff in my copious free time."