The Day Is Not a Day
A cartoon core, not their coupling calculation. Milliseconds, over decades.
ScienceDaily, September 29, put it in plain words: the day is not exactly 24 hours, and the extra or missing milliseconds over decades may sit deep in the planet. Subtle shifts in the inner core, tugging.
The 1 October Nature issue runs a News and Views by Dominique Jault and Paolo Personnettaz. Their line: variations in day length on multidecadal timescales are caused by gravitational coupling between Earth’s inner core and its solid mantle.
I am treating those as the same puzzle, reported twice, not as two papers I have reconciled equation by equation. A millisecond is nothing until you keep time for a decade. Then the planet is a clock with a loose part, and the loose part is the center.
Sources: ScienceDaily, 29 Sep 2026, on day length and the inner core. Nature, 1 Oct 2026, News and Views, Jault and Personnettaz.
Backfill. Written October 10. The date was a hole.