What method of heat transfer occurs without direct contact?

The method of heat transfer that occurs without direct contact is radiation. Radiation involves the transfer of energy through electromagnetic waves, which can happen across a vacuum or through transparent media. This means that even if two objects are not physically touching each other, heat can still be transferred from a hotter object to a cooler one through processes such as infrared radiation.

In contrast, conduction requires direct contact between materials for heat transfer to occur, relying on the collision of molecules to transfer thermal energy. Convection involves the movement of fluids (liquids or gases), where warmer, less dense portions rise while cooler, denser portions sink, transferring heat through the flow of the fluid itself. Insulation refers to materials that are designed to resist heat transfer, but it does not itself represent a method of heat transfer. Therefore, radiation is the correct answer, as it uniquely allows for the transfer of heat without any physical contact between the objects involved.