WHAT IS ENERGY

WHAT IS ENERGY?
As you know from reading the news columns, the greatest goal of science today is to obtain energy from the atom to enable man to live a life of peace and plenty. The mere idea that this can be done is one of the greatest steps forward in the history of human thought!
Albert Einstein was the first man to set up a theory that measured matter in terms of energy. In other words, he showed that matter could be changed into energy. This changed our whole way of looking at the physical world.Matter became secondary; energy became the most important thing in the physical world.
What is energy? Energy is the ability to do work. Energy is that which stands back of forces, and makes the forces possible. Let's try to understand this by considering the automobile.
To make the motor go, a force must be used. Something must provide that force. That something is energy. Where does it come from? It comes from the petrol, and the energy is let loose by burning the petrol in the cylinder. This energy puts certain forces into operation, forces which produce motion through the gears and wheels of the car. The result is that the engine does work, and energy has made it possible.
There are two kinds of energy, potential and kinetic. Firest let's understand potential energy. In the case of petrol, the molecules are held together by electrical forces. Energy is stored in these molecules, potential energy. When the petrol explodes, that potential energy is used up.
Another example of potential enegy is a suspended weight. There is stored-up energy in the weight which we can release just by letting it drop.Water at the top of a falls or behind a dam also has potential energy is used up.
Now suppose the weight drops, or the water goes down over the falls. The mere fact that it is moving at a certain speed enables it to do work, and this energy is called ''kinetic energy.'' It is energy that is derived from the weight of a moving body and its speed. As a body falls, it loses potential energy and gains kinetic energy. But the amount gained is exactly equal to the amount lost. In fact, the total amount of energy in the universe is alwasys the same. We can't create it or destroy it. What we do, whether we use falling water, coal, or tha atom, is change it from one form to another.