Heat Radiation

Heat radiation is the movement of heat particles with space particles without the need for any matter particles, whether as solid, liquid or gas.

Unlike conduction and convection, which need physical contact or material movement, radiation transfers heat at the speed of light since pure space is the medium.

Equation Interpreted in Cartesian

This is currently accounted for by the Stefan-Boltzmann Law

P = ε · σ · A · T⁴

• P = Total power radiated (watts)
• ε = Emissivity – this is the density of heat particles in the body

• σ = Stefan-Boltzmann constant (5.67 × 10⁻⁸ W·m⁻²·K⁻⁴) – this is the ratio of heat to space particles
• A = Surface area
• T = Absolute temperature (in Kelvin)

Because power scales with T⁴ (temperature to the fourth power), small increases in temperature cause massive increases in radiated heat.

This explains that the total volume of heat particles comes from the heat density (as emissivity) of the hot body, regulated by the ratio of space particles to heat particles.