Research highlighted on September 29 proposes that subtle inner-core changes can transfer angular momentum to the mantle and alter the length of day by a few milliseconds over decades. The effect is not directly perceptible in daily life.

The hypothesis combines rotation measurements with models of Earth’s interior. It must be assessed alongside atmospheric, oceanic and lunar influences, which also contribute to length-of-day variations.

Millisecond changes do not alter the ordinary calendar, but they matter for geophysics, precision navigation and understanding the planet’s internal dynamics.

Researchers are not claiming that the inner core is the only cause. The proposal is that core dynamics may contribute to observed signals alongside other known factors.

Confirmation will depend on replication, the quality of rotation data and consistency with seismological models of Earth’s interior.

For the public, the essential message is scientific: a possible physical link between the core and rotation, not an abrupt change in the day we experience.

Source consulted: ScienceDaily — Science news