Conduction . . . . .
You put a spoon into a cup of really hot coffee. After a couple of minutes,
the top of the spoon is too hot to handle. The spoon CONDUCTED the heat
from the hot liquid up to the other end.
No material moved. The heat just flowed through the material.
Convection . . . . .
You put a pot of cold water on the stove and turn on the heat. The flame
heats the water at the bottom of the pot. The heated water rises from the
bottom, and cold water from the top sinks to the bottom. Hot fluid rising,
cold fluid sinking, that's CONVECTION.
Material moved, carrying heat from place to place with it.
Radiation . . . . .
-- You come into the house on a cold day, and there's a fireplace burning
across the room. Looking at the fire, you feel heat on your face, but not on
your back, and the room is still cold.
-- The sun produces a lot of heat. Somehow, it gets to the Earth, although
there's nothing in space to carry it.
-- Heat, light, and radio don't need anything to carry them. They can RADIATE
through empty space, as electromagnetic waves.
When the waves are heat, they're called Infrared waves.
