Bibliographic record
Abstract
Abstract The spin axes of the mantle, fluid core, and solid inner core of the Moon precess at frequency Ω p = 2 π /18.6 years −1 though with different orientations, leading to viscous friction at the core‐mantle boundary (CMB) and inner core boundary (ICB). Here, we use a rotational model of the Moon and consider a range of inner core and outer core radii to investigate the relative importance of viscous dissipation at the CMB and ICB, and to show how this dissipation is connected to the phase lead angle ( ϕ p ) of the mantle ahead of its Cassini state. We show that when the inner core radius is km and the free inner core nutation frequency Ω ficn approaches Ω p , viscous dissipation at the ICB can be comparable to that at the CMB, and in the most extreme cases exceed it by as much as a factor of 10. If so, the viscous dissipation in the lunar core projected back in time depends on how Ω ficn has evolved relative to Ω p . We further show that constraints on the CMB and ICB radii of the lunar core can in principle be extracted by matching the observed phase lead of ϕ p = 0.27 arcsec; this requires an improved estimate of tidal dissipation and an accurate model of the turbulent viscous torque. Finally, when our rotational model is constrained to match ϕ p = 0.27 arcsec, our results suggest that the viscous dissipation at the ICB is likely insufficient to have ever been above the threshold to power a thermally driven dynamo.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".