Folded in
The chain
The six-link chain sits off the reading path. The parts of it that stand are carried on the pages that argue them.
Where it went
The trigger shortlist, and the two measured links.
Two links of the chain had no numbers at either end and are not carried forward.
The open step is a crowded shortlist rather than a void: six candidate triggers, one of them published as a working model of a tidally synchronised dynamo, and one of them asking nothing of anything outside the star. An argument resting on six candidates does not fall when one fails. What is genuinely missing is narrower, and is stated narrowly. The claim →
The cold, dense interstellar cloud that squeezed the Sun's protective bubble inside Earth's orbit about two million years ago is argued with the rest of the case that the room is not sealed. The calm →
The field weakening at roughly 5 per cent a century and about 9 per cent on 1840, the weak patch over the South Atlantic growing and splitting, and the north magnetic pole slowing since the late 2010s, are held with the corrections attached. The figures →