When heat is transferred, where does it always move from?

Heat transfer occurs due to differences in temperature, following the fundamental principle that energy always moves from a region of higher energy (higher temperature) to a region of lower energy (lower temperature). Therefore, heat flows from a hot object to a cold object. This process can be understood through the concepts of conduction, convection, and radiation, all of which are methods through which heat is transferred.

For instance, in conduction, heat moves through direct contact, where the molecules in the hot object vibrate more rapidly and collide with nearby slower-moving molecules in the cold object, transferring energy and increasing the temperature of the cooler surroundings. Similarly, in convection, warmer fluids rise and create a cycle that facilitates the movement of heat from warmer areas to cooler ones. Radiation, on the other hand, allows heat to be transferred through electromagnetic waves, again from warmer bodies to cooler ones in their vicinity.

In summary, the correct understanding of heat transfer reinforces that it inevitably flows from hot to cold, which is consistent with thermodynamic principles.