Fact check
“The competition between the gravity of the inner core and other forces in the mantle is altering the Earth's rotation.”
Reasoning
The supplied sources report that researchers have identified a competition between the gravity of the inner core and forces in the mantle that produces small accelerations and decelerations in Earth's spin, altering the length of the day. The article references seismic estimates, mantle flow models, and a reconstruction of Earth's spin from 1964‑2019 that matches observed variations, directly supporting the claim.
On confidence: Multiple excerpts from the same WIRED article cite a peer‑reviewed Nature paper describing a gravitational interaction between the inner core and mantle that influences Earth's rotation.
Important context
The effect is described as minute, causing only small changes in day length over decades. The model does not account for all possible forces, but the identified mechanism is presented as a major component of observed variations.
Evidence
Supporting (4)
- Tier 1 — Primary sourceA Gravitational Battle Within the Earth Is Changing the Length of Days | WIRED
Jorge Garay Science Sep 26, 2026 5:30 AM A Gravitational Battle Within the Earth Is Changing the Length of Days A competition between the gravity of the inner core and other forces in the mantle is altering the Earth's rotation. The layers…
- Tier 1 — Primary sourceA Gravitational Battle Within the Earth Is Changing the Length of Days | WIRED
published this week in Nature , researchers believe they have identified one of these hidden gears. They propose that the gravity of the inner core pushes rotation in one direction, while other interactions between the core and the mantle…
- Tier 1 — Primary sourceA Gravitational Battle Within the Earth Is Changing the Length of Days | WIRED
be aligned,” Mathieu Dumberry, a geophysicist at the University of Alberta involved in the study, said in a press release . What this means is that gravity tries to pull the layers of the inner Earth back into their more harmonic position,…
- Tier 1 — Primary sourceA Gravitational Battle Within the Earth Is Changing the Length of Days | WIRED
gradual changes that had been observed over the decades. Other yet-unknown factors are likely involved, but this proposal unravels a major component of our variable days. The model also didn’t account for all the forces competing involved,…
Limitations
All evidence comes from a single news outlet summarizing a Nature study; the original research article is not provided, so verification of methodological details is limited to the reporting source.
- Last verified:
- Sep 27, 2026, 4:05 AM CDT
- Pipeline:
- 2.1.0
- Claim type:
- Causal
Where this claim appeared
A Gravitational Battle Within the Earth Is Changing the Length of DaysWired · Jorge Garay