Which method of heat transfer occurs without the need for a medium?

The method of heat transfer that occurs without the need for a medium is radiation. Radiation is the transfer of heat energy through electromagnetic waves, which can travel through the vacuum of space. This means that heat can be transferred from one body to another without any matter or medium in between. A prime example of radiation is the heat from the sun warming the Earth; the energy travels through the vacuum of space, illustrating that radiation does not require a physical substance to facilitate the transfer of heat.

In contrast, conduction requires materials to transfer heat through direct contact between molecules, while convection involves the movement of fluids (liquids or gases), which carries heat as the fluid circulates. Induction is a method of transferring energy through electromagnetic fields and is not a direct form of heat transfer. Thus, radiation stands out as the unique method capable of transferring heat without reliance on any material medium.