Thermal Energy

What is thermal energy ?

          The ultimate source of energy available to man is the sun, the huge thermo-nuclear furnace that supplies the earth with the heat and light that are essential to life. The sun produces thermal energy (heat energy) in the form of radiation. Thermal energy is heat energy in transfer. Heat is a form of energy. When heat it is in the process of being transfered, it is called thermal energy.



           At a more basic level, thermal energy comes form the movement of atoms and molecules in matter. It is a form of kinetic energy produced from the random movements of those molecules.

           When you put your hand over a hot stove you can feel the heat. The atoms and molecules in the metal of the burner are moving so rapidly that they transfer the electrical energy from the wall outlet to thermal (heat) energy thru friction. We all know what happens when we rub our hands together. The same way, atoms and molecules rubbing against each other produce heat. Scientists like to call that heat thermal energy.

Laws of Thermodynamics

When talking about thermal energy we must also talk about the laws of thermodynamics which express the laws of the interaction of energy and matter.

First law of thermodynamics: Energy and matter are interchangable but cannot be created or destroyed. The total amount of energy in the whole universe remains constant, only changing from one form to another.

Second Law of thermodynamics: This law states that any system always tends to move toward it's probable state of energy. For example, a spring watch will run until the potential energy in the spring is used up. If no new energy is input into it (in the form of winding the spring up) then it has returned to it's most probable state, which is really not to run. The most misunderstood law.

Third Law of Thermodynamics: This law is a little more complicated and deals with the state of a system of atoms and molecules at an absolute zero temperature. Absolute zero is theoretically impossible to achieve considering any force acting upon the atoms and molecules to remove heat from them are not at absolute zero and therefore cannot make anything else reach absolute zero. The third law says that entropy of atoms and molecules at absolute zero is zero.