AI Rewrites Lunar History: Rediscovering Ancient Equations

Author: Denis Avetisyan


A new approach using artificial intelligence has successfully recreated a fundamental equation describing the Moon’s orbit, demonstrating the power of AI in astronomical discovery.

The monthly fluctuation of lunar declination is charted against its right ascension, exposing a predictable celestial dance governed by orbital mechanics.
The monthly fluctuation of lunar declination is charted against its right ascension, exposing a predictable celestial dance governed by orbital mechanics.

AI Feynman, guided by embedded physical biases, has rediscovered the first-order form of the Lunar Equation of the Centre from orbital data.

Despite longstanding successes in celestial mechanics, automatically rediscovering physical laws from observational data remains a significant challenge. This work, ‘Rediscovering the Lunar Equation of the Centre with AI Feynman via Embedded Physical Biases’, explores the application of the AI Feynman symbolic regression algorithm to recover a fundamental astronomical equation – the Equation of the Centre – from lunar ephemeris data. By incorporating physics-inspired observational biases, we demonstrate successful automated recovery of the equation’s first-order form, yet also reveal limitations related to coordinate system selection. Could strategically embedding domain knowledge further unlock the potential of symbolic regression for uncovering hidden relationships within complex physical systems?


Deconstructing the Lunar Dance

Accurate lunar motion modeling, essential for modern navigation and celestial mechanics, requires accounting for deviations from idealized Keplerian orbits. Traditional analytical methods, reliant on series expansions, are computationally expensive and struggle with convergence. Subtle variations like the ‘variation’ and ‘evection’ complicate matters. Successfully modeling these perturbations – though small individually – is crucial for understanding long-term lunar behavior, demanding a deep understanding of gravitational interplay.

Automated Data Sculpting

This methodology begins with an Automated Preprocessing Extension, converting raw Lunar Ephemeris Data into optimized Coordinate Systems for subsequent analysis. A generated Pareto Frontier visually represents the trade-offs between model complexity and accuracy, allowing users to tailor solutions to specific needs. Dimensionality reduction via Principal Component Analysis streamlines data handling, minimizes computational cost, and enhances robustness across differing reference frames.

Relearning Lunar Equations

Applying AI Feynman, a symbolic regression technique, allows rediscovery of the Equation of the Centre directly from observational data, bypassing traditional derivation. The algorithm’s search space includes trigonometric and Bessel functions. Analysis of the Anomalistic Cycle, representing the time between lunar perigees, provides critical validation. This method successfully rediscovered the first-order analytical form of the lunar Equation of the Centre, estimating lunar eccentricity at 0.0571662 – a 0.235% deviation from observed values.

Beyond Prediction: A New Celestial Mechanics

A novel framework surpasses the limitations of traditional series expansion techniques, leveraging automated equation discovery for highly accurate orbital representations, particularly beneficial for complex systems. Rediscovered equations demonstrate improved accuracy and computational efficiency in predicting lunar orbits, critical for precise space mission planning and long-term lunar exploration. This method addresses challenges in modeling gravitational interactions and orbital perturbations, revealing potential pathways for analyzing other celestial bodies and diverse physical systems. Further research will focus on algorithm refinement and uncovering previously unknown physical relationships – for every bug reveals a hidden design.

The pursuit within this study echoes a sentiment articulated by G. H. Hardy: “A mathematician, like a painter or a poet, is a maker of patterns.” This research doesn’t simply find the Equation of the Centre; it actively constructs understanding from raw data, much like an artist shaping clay. The embedded physical biases aren’t constraints, but guiding principles that focus the AI’s pattern-seeking abilities. By strategically introducing these biases, the system isn’t limited by a search space; it’s directed towards the inherent symmetries and relationships within the lunar ephemeris, effectively reverse-engineering the celestial mechanics at play. This echoes the core idea of leveraging symbolic regression not as a brute-force search, but as an intelligent exploration of mathematical structure.

Where Do the Fault Lines Lie?

The rediscovery of the Lunar Equation of the Centre via automated symbolic regression is, predictably, not the destination. It is, rather, a carefully illuminated point of failure. The system worked, yet its dependence on embedded physical biases reveals a fundamental constraint: the machine isn’t discovering laws so much as retracing steps, guided by preconceptions. Every exploit starts with a question, not with intent. The true challenge lies not in replicating known solutions, but in allowing the algorithm to stumble upon the unexpected—to articulate a perturbation not yet imagined, a resonance previously undetected.

Current limitations are not computational, but conceptual. The framing of the problem—defining canonical coordinates, selecting relevant observables—implicitly encodes a particular worldview. Future work must address this inherent subjectivity. Can the system be made to question the initial conditions, to explore alternative coordinate systems, or to identify observables beyond those traditionally considered ‘significant’? The path forward necessitates a meta-layer of inquiry, an algorithmic skepticism directed inward.

Ultimately, the value of ‘AI Feynman’ isn’t in its predictive power, but in its capacity to expose the fragility of existing models. It is a tool for controlled demolition, designed to reveal the cracks in our understanding. The next iteration should not strive for greater accuracy, but for more elegant failures—failures that point toward a more complete, and perhaps more unsettling, picture of the cosmos.


Original article: https://arxiv.org/pdf/2511.09979.pdf

Contact the author: https://www.linkedin.com/in/avetisyan/

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2025-11-14 15:21