Time III

See here.

A clock measures a linear, unidirectional timeline whereas clouds are diffuse and dissipate in different directions.

In 1245beta AD, when the probability clouds have diffused away from the Time Patrol's timeline, Holy Roman Emperor Frederick says not "...if God allows...," but "'...if time allows.'" (The Shield Of Time, p. 395) Does he intuit that a quirk in time has given him his prevalence over the Popes? He and his followers ignore the call to vespers.

Everard thinks:

"...changes in time don't spread outward on any simple wave front." (p. 399)

They don't. In fact, Everard had already said:

"'The effects of a change propagate across the world at varying speeds, depending on factors like distance, ease of travel, and closeness of relations between countries.The Far East might begin to be touched, slightly, pretty soon; but the Americas may well go on unaffected for centuries, Australia and Polynesia longer still. Even in Europe, at first the differences are probably mainly political. And...that's a whole new political history, about which we here [back in 18,244 BC] know nothing.'" (p. 300)

Even though people in the Americas etc do not know it, they are in fact in an altered timeline so some of their decisions might differ from those that they had made in the original timeline? The Everard who is merely thinking on p. 399 continues:

"They're an infinitely complicated interplay of quantum functions, way over this poor head of mine." (p. 399)

Another disclaimer of understanding, the author signaling to the reader that the attempted explanation will cease here. When Everard spoke on p. 300, he made an obvious point whereas, when he thinks on p. 399, he invokes quantum mechanics yet again. We already know that a temporal change can be caused either by a time traveler or by a quantum fluctuation in space-time-energy. Now we are told that, however the change is caused, its spreading effects are interacting quantum functions.

"The tiniest alteration could conceivably annul an entire future, if the event was crucial." (p. 399)

But have we not been told that such crucial events are rare? Now we are told something slightly different although the practical implication may be the same:

"There should theoretically be countless such; but hardly ever were they felt. It was as if the time-flow protected itself, passed around them without losing its proper direction and shape. Sometimes you did get odd little eddies - and here one of them had grown to monstrousness -" (ibid.)

The use of the words "flow" and "eddies" shows that this is the familiar river of time metaphor. Does a potentially future-altering event resemble a boulder that the river flows around without being deflected? When the boulder shifts in a storm, then the course of the river might change?

Then the thinking Everard reverts to his earlier explanation of why a change is slow to affect the rest of the world:

"Yet change must needs spread in chains of cause and effect. Who outside the immediate vicinity would ever even hear what went on, or did not go on, in a couple of families of Anagni? It would take a long time for the consequences of that to reach far. Meanwhile the rest of the world moved onward untouched." (p. 399-400)

But we do not need quantum functions to understand that.

Denison wondered whether his being trapped in two divergent timelines was more than coincidence. Of course, the real reason was that Poul Anderson wanted to revive Denison as a character in the novel but, as I said about Guion, no one can tell Denison that.