Radiation

From GAWDAwiki

Radiation is the transfer of heat when energy is emitted in the form of electromagnetic waves. Without an intervening medium, this leads to heat transfer between substances with different temperatures. Radiation does not require a material medium.

Other forms of heat transfer include conduction and convection.^[1]

References

1. http://www.spiraxsarco.com/resources/steam-engineering-tutorials/steam-engineering-principles-and-heat-transfer/heat-transfer.asp