​Heat Transfer Key Concepts

• ​Heat is the movement of thermal energy from one object or substance to another.

• ​Heat is transferred by conduction, convection, or radiation.

• ​Conduction is the transfer of heat from two objects in direct contact with each other (touching). Heat moves from the warmer object or substance to the cooler. This is how you burn your skin if you touch something really hot!

• ​Radiation is the transfer of heat in electromagnetic waves, or rays. This is the only way heat can move through a vacuum (empty space), therefore it is how the Sun's energy travels to Earth.

• ​Convection is the transfer of heat throughout fluids (substances that flow, like liquids and gases). As fluids are heated their particles move faster and they become less dense and rise (away from their heat source) and then cool and sink, creating circular convection currents.

• ​Water heats and cools more slowly than land and air, which creates land and sea breezes that keep coastal climates more moderate than their inland neighbors.