Constants

Definition

Constants are fixed values that do not change within a given mathematical expression, physics model, or programming context.

Why It Matters

Constants anchor mathematical systems and physics laws (e.g. speed of light $c$, gravitational constant $G$), providing stable baselines that define the scale and limits of reality.

Core Concepts

• Mathematical Constants: Value is invariant (e.g. $\pi \approx 3.14159$, $e \approx 2.71828$).
  • How to read: “pi is approximately three point one four one five nine; e is approximately two point seven one eight two eight.”
  • Meaning: Fixed mathematical ratios that do not change regardless of the coordinate system.
• Physical Constants: Universal values governing the laws of physics (e.g. Planck’s constant $h$, Boltzmann’s constant $k_B$).
  • How to read: “h is Planck’s constant; k sub B is Boltzmann’s constant.”
  • Meaning: Fundamental physical parameters of the universe.

Connected Concepts

• Variables