The Growth Of An Idea III

We continue to analyze a long italicized passage in Poul Anderson, "The Year of the Ransom" IN Anderson, Time Patrol (Riverdale, NY, 2010), pp. 641-735 AT pp. 671-673.

To summarize the line of thought after the tough rubber bands analogy:

usually a time traveler is part of the past;

he was "always" there (sure, if someone is going to depart into the past, then he was in the past);

any anachronistic behavior might be noticed but will be forgotten.

Then the text reads:

"It's a philosophical question whether or not reality keeps flickering through such insignificant changes." (p. 672)

I do not think that it needs to "flicker." A time traveler spends a period of time in an earlier century, e.g., six months in 1533. Everything happens just once:

his six-month visit;
any anachronistic behavior on his part;
any comments made on his behavior;
the fading of memories of that behavior.

All of this is a one-shot affair, not a "flickering."

Next, the passage cites two actions that would make a difference:

arming Attila with machine guns;
preventing Lenin's parents from meeting.

The time traveler who had changed history so drastically that he prevented his own birth would effectively not be a time traveler who had changed history. Instead, he would be:

"...an effect without a cause, thrown up into existence by that anarchy which is at its foundation." (ibid.)

That way of putting it changes everything. The Time Patrol universe contains two distinct phenomena:

time travelers, who depart from one time and arrive at another;
quantum changes to the timeline -

- and the quantum changes are of two kinds:

merely a different course of history, e.g., King Roger dying, instead of surviving, at the Battle of Rignano;
the appearance of what looks like a time traveler in or on what looks like a time machine.

I say "...looks like..." because, in this case, the apparent time traveler will not depart from the future but instead initiates a future in which he will not be born. There are two possible explanations of the appearance of an apparent time traveler. The first is the same quantum randomness that generates a different course of history. The second is proposed in The Logic of Time Travel: Part I but, to summarize here:

an earlier event, A, occurred and would have been a remote cause of B, the birth and life of a time traveler and his departure into the past;
B would in turn have caused C, the arrival of the time traveler later than A but earlier than B;
however, C occurs and prevents B;
thus, the sequence AC looks like a discontinuity but is in fact a consequence of the logic of time travel with causality violation.

Now there is one unresolved issue. I do not think that it makes sense for a time traveler who is about to depart into the past to think that he might turn out to be an apparent time traveler as described here. SM Stirling has commented that I am assuming an absolute time and that infinite discontinuities in a time traveler's world line can incorporate what I regard as a logical contradiction. I welcome further comments from Mr Stirling or from anyone to make this idea clearer. However I try to clarify the Time Patrol, I am left with, to me, an unresolved paradox.