What We Experience And How We Talk About It

Experience: The Sun seems to go around the Earth.

How we talk about it: Either we assume and state that the Sun goes around the Earth or we learn that the opposite is the case.

Therefore: One experience and two ways of talking about it although both ways are not equally valid.

Some sf characters experience what, following Wells, they call "time travel." (He wrote "time travelling" but we shorten it.) We can ask: Is the author's description of his characters' experience at least consistent, therefore logically, if not also physically, possible? Do we agree with their way of talking about their experience, e.g., is it really a kind of travel?

In Poul Anderson's Time Patrol series, a "time traveller" can have the following experience. He arrives in what looks to him like the past but he can alter the course of events so that he is no longer in the past as he had known it. He can even prevent his own birth. However, he cannot affect any of the events that had occurred before he started to alter the course of events. Therefore, preventing his birth does not prevent his arrival. So far, this is logically possible although both counterintuitive and contrary to known physical laws.

The character remembers a sequence of events, or a "timeline," in which he had been born, grew up, mounted a timecycle and departed into "the past." He experiences a timeline in which he has appeared as if from nowhen and has prevented his own birth. In neither of these timelines does he exist into adulthood, then disappear, although it is sometimes stated that this would be a consequence of time travel.