Explain briefly the process of heat transfer by radiation.

Radiation is the transfer of heat through electromagnetic waves without requiring any medium. It can occur even in a vacuum.

How it works

• All hot objects emit infrared radiation.
• These rays travel straight through space and are absorbed by other surfaces.
• The energy absorbed increases the temperature of the surface.

Examples

• Heat from the Sun reaching Earth.
• Feeling warmth near a fire even without touching it.
• Heat lamps used in food warmers.

Characteristics

• Does not need a medium (works in space).
• Travels at the speed of light.
• Dark, dull surfaces absorb radiation better than shiny surfaces.