Physics glossary for programmers
These definitions use the same language as the course: inputs, state, rules, outputs, tests, and model limits. They are concise on purpose; each lesson adds the physical detail needed for its own question.
- assumption
- A statement the model takes as true so it can answer a narrower question.
- boundary condition
- A rule at an edge of a modelled region, such as a fixed end of a string or a voltage reference node.
- conservation law
- A quantity that stays constant for an isolated model; in code, it is a powerful test oracle.
- coordinate system
- The declared basis and origin used to store a position or vector as components.
- differential equation
- A rule for local change. A numerical solver turns it into repeated finite steps.
- field
- A function that gives a value at each position, such as pressure, temperature, or electric force per charge.
- invariant
- A property expected to remain true under a valid update, transformation, or limiting case.
- model
- A deliberately limited representation that maps inputs and state to observable outputs.
- numerical error
- A measurable difference introduced by finite precision or a numerical method, not new physical behaviour.
- observable
- A quantity the model predicts that a reader could inspect, measure, plot, or compare.
- parameter
- A named model setting that stays fixed during one run but can change between experiments.
- state
- The smallest data that must survive to calculate the model's next step.
- unit
- The physical type of a number, such as metre, second, or joule. A bare number is incomplete physical data.
- validation
- Comparing model output with a known answer, invariant, limiting case, or measurement.
- vector
- A value with magnitude and direction, represented by components only after a coordinate basis is declared.