Mathematical Models and the Newtonian Worldview
Further Reading: Differential Equations
Recommended Textbooks: Blanchard, Devaney, and Hall () is highlighted for its dynamical systems perspective and balance of qualitative, numerical, and analytic methods.
Mathematical Biology Resources: Key texts include Britton (), Edelstein-Keshet (), Ellner and Guckenheimer (), Garfinkel et al. (), Mangel (), and Vandermeer and Goldberg ().
The Newtonian Mechanistic Worldview
Newton's Principia (): Isaac Newton established a unified account of gravity and three universal laws of motion, framing the universe as a machine governed by unchanging mathematical rules.
Core Assumptions: The traditional view assumes that simple mathematical laws lead to simple, predictable behavior. Complexity was historically thought to arise only from many interacting objects or non-simple laws.
Laplacian Determinism
Laplace's Demon (): Pierre-Simon de Laplace posited that a "vast intelligence" knowing the position and forces of all particles could perfectly predict the past and future.
Scientific Requirements for Prediction: 1. Knowledge of the universal laws of nature. 2. Accurate measurements of the current state. 3. Sufficient computing power.
Challenges from Dynamical Systems: Modern study of chaos shows that even simple deterministic systems can be unpredictable due to sensitive dependence on initial conditions.
Styles and Levels of Mathematical Models
Faithful vs. Caricature Models: Some models aim for exact quantitative prediction (like projectile motion), while others (caricatures) highlight essential features or qualitative traits (like an artist's sketch in a bird guide).
First-Principles vs. Empirical Models: * First-principles: Mechanistic models based on fundamental laws governing a system's constituents. * Empirical: Descriptive models (e.g., linear regression) that capture trends in data without explaining the underlying mechanism.
Abstraction Levels: Elements in models range from physical objects (point particles) to coarse-grained variables like temperature, population, and density.
Agent-Based Models (ABMs): Instead of using population averages, ABMs simulate the movement and interaction of individual entities (agents) to see emergent behavior.
Pluralistic Modeling
Contextual Effectiveness: The value of a model depends on its purpose. For example, a fetal pig and a mannequin are both valid models of a human body, but only for specific, non-interchangeable goals (physiology vs. clothing design).
The Pluralistic View: No single model is "true." A full understanding of complex systems requires multiple models at different levels to illuminate various facets of the phenomenon.