Applied Mathematics and Four Ways of Thinking

Jun 19, 2024

Lecture Notes on Applied Mathematics and Thinking Strategies

Introduction

  • Speaker: Applied mathematician, visiting for the third time
  • Background: Formerly worked at Oxford University until 2005
  • Key message: Focus on understanding the world through mathematics, not just calculations

Four Stages of Thinking in Mathematics

  1. Statistical Thinking
  2. Interactive Thinking
  3. Chaotic Thinking
  4. Complex Thinking

Statistical Thinking

  • Ronald Fisher: Pioneer in applied mathematics and statistics
    • Background: Arrogant, believed he was smarter than professors
    • Contribution: Connected math to reality; worked on significant statistical experiments
    • Example: Tea tasting experiment to test if milk first or tea first makes a difference
      • Experiment Methods:
        • Pairwise challenge (less effective)
        • Tray method (more effective; better discrimination)
      • Mathematical Insight: Probabilities and combinatorics used to show tray method is superior
    • Legacy: Developed foundational principles in experimental design, still used today
  • Statistics in Sports:
    • Example: Gary Neville's skepticism on measuring player's impact after a goal down
    • Measure: Performance of players (e.g., Trent Alexander Arnold) and statistical significance
    • Gary Neville Statistic: Used Fisher’s exact test to measure impact accurately
  • Limitations of Statistics:
    • Small Effect Size: Example of grit in success (Angela Duckworth's study, 4% variance)
    • Moral and Scientific Issues: Fisher’s support of eugenics and anti-smoking campaigns
    • Key Points:
      • Doesn't provide all answers
      • Effect sizes might be small
      • Correlation ≠ causation

Interactive Thinking

  • Key Figure: Alfred J. Locker, shifted from chemistry to mathematical biology
  • Model Example: Predator-prey dynamics (rabbits and foxes)
    • Unbalanced Equations: Imagining reactions, leading to differential equations
    • Interpreting Equations: Rate of change and causative factors
  • Applications:
    • Social Interactions: Clap experiments, social recovery
    • Fish Behavior: Modeling fish movements and escape waves
    • Football: Marking territory and attacking strategies (e.g., Marcus Rashford's runs)
  • Limitations: Models often need more than just interactive elements, Lotka’s incomplete models

Chaotic Thinking

  • Margaret Hamilton: Pioneer in software engineering and chaos theory
    • Background: Worked with Edward Lorenz on weather prediction models
    • Butterfly Effect: Small changes lead to vastly different outcomes
    • Demonstration: Exercises and cobweb diagrams
    • Practical Application: Reliable software for Apollo moon mission
  • Key Insights:
    • Embrace chaos, but control important aspects
    • Balance between order (Yang) and disorder (Yin)

Complex Thinking

  • Simulation Example: Cellular automata and simple rules creating complex patterns
  • Hero: Andrei Kolmogorov
    • Definition of Complexity: Length of the shortest description that captures detail and nuance
  • Implication: Capturing complexity can enhance understanding and modeling in mathematics

Conclusion

  • Find balance in applying different mathematical thinking strategies
  • Recognize the limitations and potential of each strategy
  • Consider reading the speaker’s book for more insights on complex thinking