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 its 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
its 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.