The Accidental Time Machine

Author: Joe Haldeman

Imagine inventing a time machine by accident! Well, Matt does, and it's a doozie. Built-in safety: can only travel into the future. Built-in quirk: every subsequent jump will be longer than the previous one by a factor of 12. Predictably, things don't go smoothly for Matt, as each time he jumps forward, he ends up in a place he'd rather not be (usually for excellent reasons), and every time he jumps, the interval increases. He and a woman that joins him along the way (Dr. Who, anyone?) end up thousands of years in the future, together with an over-intelligent and unfriendly AI. Fortunately they come across some super-beings that can actually send them back along the time stream; which they do. However, because of an inherent spatio-temporal limitation (you can be sent with limited precision to a given place and time, and the better you determine one, the more uncertain the other becomes; think Heisenberg!) they end up before Matt was actually born, in the late 1800s.Why it's on this list: An engaging story, which suggests a solution to the 'temporal paradox' problem. If you can only go forward, you can't screw up the past. On the other hand, you can't ever go back either...