Thermal radiation is a form of electromagnetic radiation emitted by any object with a temperature above absolute zero (-273.15°C or 0° Kelvin). It’s a result of the movement of charged particles within the matter.
- When charged particles change energy states, they release energy in the form of electromagnetic waves.
- The frequency and intensity of this radiation depend directly on the object’s temperature.
- All matter consists of atoms and molecules in constant motion. This motion has kinetic energy, which is associated with the temperature of an object.
- As temperature increases, the motion of the particles becomes more agitated. This causes charged particles within the matter (like protons and electrons) to accelerate and change their energy states.
- Thermal radiation covers a wide range of the electromagnetic spectrum. However, much of it falls within the infrared region, which we experience as heat. Hotter objects emit more thermal radiation and a higher proportion of radiation in the visible light spectrum. This is why very hot objects can start to glow red or white.