1: Systems and System Models

Systems and System Models

• A system is a portion of the universe, distinct from the rest. It simplifies the study of the universe.
• Forces, matter, and energy act on a system, altering its internal state.
• Systems range from large (galaxies) to small (fundamental particles).
• Systems have defining characteristics:
  • Boundary: Separates the system from its surroundings.
  • Components: The parts that make up the system.
  • Resources: Matter and energy that enter or leave the system.
  • Feedback Mechanism: Maintains the system's state.

Mental Models vs. System Models

• A mental model is an individual's internal representation of a system. It's unique, unstable, may be incomplete, and not always accurate.
• A system model is a shared, external representation that illustrates how a system operates. It's clear, stable and can be refined.

Emergent Properties

• Emergent properties are characteristics appearing at a higher level of organization within a system. They weren't present at lower organizational levels.
• For example, molecules of chlorophyll have different properties than chloroplasts, which differ from leaves, trees, and so on.

System Models in Engineering

• System models are vital in engineering to analyze and control system inputs and outputs.
• Systems engineering breaks down complex projects (like space stations) into manageable systems and coordinates team efforts.

Constructing System Models in the Classroom

• Early grades: Students start by drawing, describing and including invisible aspects (like forces) in their representations.
• Middle and High School: Mathematical relationships (data and equations) are incorporated to quantify system behaviors.
• Progression: Start with simple models, then increase their complexity.
• Limitations and Assumptions: Students should identify potential limits and assumptions impacting model accuracy.

Examples of System Models

• Science Notebook: A place for recording observations and data.
• Lego Models: Representations of systems through tangible building materials, descriptions, and sharing of ideas.
• Carbon Cycle Diagram: Shows carbon's movement in the environment, encompassing visible (plants) and invisible (carbon dioxide) components.
• Climograph: Depicts temperature and precipitation data for a region, comparing different biomes.
• Gears: Used to demonstrate mathematical relationships between gear sizes and rotation speeds.

Importance of System Models

• System models enable a better understanding of specific portions of the universe.
• They are essential in science and engineering.
• Identifying limitations and refining models improves our understanding of the world.

Explore the fundamental concepts of systems and system models, including key characteristics such as boundaries and feedback mechanisms. Understand the differences between mental models and system models, and their importance in grasping complex systems.