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.