Mutable Time Theory

In "The Sorrow of Odin the Goth":

Causal loops are subtle. An incipient causal loop is dangerous because it can set up a resonance which can cause changes of history that multiply catastrophically. The loop is made safe by closing it.

In "Star of the Sea":

Causal loops often have a powerful and subtle force. It is necessary to prevent a causal loop from developing into a causal vortex.

Terminology

Causal loop:

"'The time traveler becomes a cause of the selfsame events he set out to study or otherwise deal with.'" (Time Patrol, p. 448)

"'...our investigation of a disturbance to the plenum is what brought it about.'" (p. 559)

Clear. But what are:

an incipient causal loop?

a resonance?

a causal vortex?

The changes of history multiplying catastrophically sound as if they might be a vortex.

Everard has to rely on intuition based on a lot of experience:

"'I looked deeper into your case mainly because of a hunch, an uneasy feeling that something wasn't right.'" (p. 448)

His assessment of a situation can change:

"'No, this is no slight ripple in the time stream. This is a maelstrom abuilding. We've got to damp it out...'" (p. 450)

Yet later:

"'...that was quite a minor eddy in the time stream, easily damped...'" (p. 566)

Again, intuition is involved:

"'This is different. I don't know how it is, but I feel it in my marrow.'" (ibid.)

Only intuition can respond to unpredictability.