Which method does NOT describe heat transfer?

The method that does not describe heat transfer is thermal expansion. To understand this, it's important to differentiate between the mechanisms of heat transfer and the effects of heat transfer on materials.

Radiation, convection, and conduction are all processes by which heat energy moves from one location to another.

• Radiation involves the transfer of heat in the form of electromagnetic waves and does not need a medium to occur. For instance, sunlight warming the Earth is a form of radiative heat transfer.

• Convection involves the movement of heat through fluids (liquids or gases) and occurs when warmer areas of a liquid or gas rise while cooler areas sink. This process creates a current that transfers heat throughout the fluid.

• Conduction refers to the direct transfer of heat between materials that are in contact with each other. When one end of a metal rod is heated, the kinetic energy is transmitted through collisions between adjacent molecules until the entire rod is warm.

In contrast, thermal expansion is not a method of heat transfer but rather a physical change in a material that occurs when it is heated. When materials warm up, their molecules move more vigorously and tend to occupy more space, causing the material to expand. This phenomenon is a