The Stefan–Boltzmann constant is a fundamental physical constant that serves as the proportionality factor in the Stefan–Boltzmann law, which describes the total energy radiated per unit surface area of a blackbody per unit time.
Key points:
- It relates the power radiated by a perfect blackbody to the fourth power of its absolute temperature.
- The constant is denoted by the symbol σ (sigma) and has a value approximately 5.67 × 10⁻⁸ W·m⁻²·K⁻⁴.
- It allows calculation of how much energy objects like stars and planets emit based on their temperature.
Why it matters:
The Stefan–Boltzmann constant is essential in astrophysics, climate science, and thermal engineering for understanding heat transfer through radiation and predicting the thermal emission of bodies.