AffineDrift — Scientific Notes on Golf Mechanics, Modeling, and Control

Scientific notes on golf-swing mechanics, multibody dynamics, and nonlinear control, connecting mathematical models to empirical evidence.

Plain-Language Summary

AffineDrift shares scientific notes on the golf swing. It joins mechanics, control theory, and open code. You can start with simple ideas, test models in code, or read technical articles.

Welcome to AffineDrift

AffineDrift

Scientific Notes on Golf Mechanics, Modeling, and Control

Understand the golf swing through the physics of passive momentum and active muscular control.

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Three Ways In

Curious Reader & Golfer

Start with simple physical concepts and intuitive analogies before diving into mathematical equations.

Student & Coach

Explore biomechanical models, practical swing trade-offs, and torque delivery mechanisms on the lesson tee.

Researcher & Engineer

Inspect governing equations, testable falsification criteria, calibration roadmaps, and companion simulation code.

The Big Idea at a Glance

Drift plus control vector field decomposition showing passive drift and active control push
At every instant of the golf swing, total motion splits into two physical parts. Passive mechanics, gravity, and body momentum create the drift. Muscular torque and golfer effort supply active control. Combining passive swing geometry with timed muscular input directs the clubhead into the ball, showing that the swing is not muscular force fighting against nature, but steering within it.
In Symbols (Show Mathematical Formulation)
$$\dot{x} = f(x) + G(x)u$$

Here f(x) is the passive drift, representing what unforced mechanics, inertia, and intersegmental couplings do on their own. G(x)u is the control input, representing torques exerted by the golfer.

Drift plus control Phase plane of a pendulum model. A passive drift arrow and a torque push arrow add head to tail to give the state velocity. drift f(x) push G(x)u actual angle θ (rad) angular velocity ω (rad/s)
Drift plus control. At every state, the model's motion is a passive drift (blue) plus a push from the declared input (orange). Dashed: the same model with zero torque. Illustrative values from the pendulum model in src/tangent_models/examples.py; not a golfer measurement.
Long description

The horizontal axis is the pendulum angle from straight down, in radians; the vertical axis is its angular velocity, in radians per second. Faint arrows show the drift: the direction the model's state moves at each point with no torque. Both runs start at rest at an angle of -2.2 rad. The dashed curve is the zero-torque run, which follows the drift alone. The solid curve is the run under a constant 5 N m pivot torque, which swings faster and further. At the marked state, angle -1.94 rad and angular velocity 2.68 rad/s, three arrows show the change over 0.35 s: the drift arrow (2.68, 9.16) per second, the push arrow (0, 5.00) per second, which only changes angular velocity because torque acts on acceleration, and their sum, the state velocity the run actually has.

Scientific Rigor & Transparency

AffineDrift separates mathematical identity from simulation results and human evidence. We maintain public audit ledgers, critique records, and empirical validation criteria for every thesis.

Adversarial Critique Ledger

Documented counterarguments, edge-case falsifications, and technical responses across all published models.

Core Theses Claim Registry

Formal catalog of mathematical and physical claims with explicit proof chains and verification status.

Model-to-Human Validation Roadmap

Protocols for testing simulation findings against empirical laboratory data and human biomechanical experiments.

Scope & Limits

Explicit boundaries of what the control-affine framework establishes, and how to read the evidence ladder.

Connect

Each work carries an explicit maturity state (Available, Experimental, or Planned); public availability does not imply peer review or validation. Read the Evidence.

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Citation

BibTeX citation: Download .bib
@online{untitled,
  author = {},
  title = {AffineDrift — {Scientific} {Notes} on {Golf} {Mechanics,}
    {Modeling,} and {Control}},
  url = {https://affinedrift.com/},
  langid = {en}
}
For attribution, please cite this work as:
“AffineDrift — Scientific Notes on Golf Mechanics, Modeling, and Control.” n.d. https://affinedrift.com/.