Transcript: Convection is heat transfer through the motion of masses of material. It’s a very efficient way to transfer a thermal energy. If you poured boiling water into a bath and just waited, the extra kinetic motion of the molecules in the boiling water would eventually diffuse through the bath, heating up the bath, but if you swirled around the water with your hand the bath would heat up more quickly. The swirling of the water corresponds to convection. Similarly, when you boil a pan of water, as the water starts to boil motion is being carried by diffusion from the bottom of the pan towards the top of the pan. Eventually that process is not efficient enough, and the water starts to move in rolling motions carrying heat from the bottom to the top by convection. A similar process works within the Earth’s atmosphere due to the heating effect of the ground causing churning motions of air packets moving up as they are hot and down as they become cooler.