In 1905, Albert Einstein set forth his theory of relativity, in which he demonstrated that the speed of an object must be measured against some other object, either moving or standing still. There is no reason to merely suppose that an object is moving at sixty miles an hour without comparing its speed. For example, a car may be moving at sixty miles an hour, compared with the highway, which is standing still, but the car will be moving at 20 miles an hour in comparison with another car, moving in a similar direction, at forty miles an hour. This means that all motion is relative and should be measured in comparison or relation to some standard that is considered to be standing still. Einstein concluded that all matter is in motion. Energy is deemed to be matter in motion. When talking about matter, as if it were at rest, we are saying in other words, that it has energy. On the other hand, when talking about matter, as if it were moving, we are saying that it has kinetic energy.
There are all kinds of energy. A truck that is moving has mechanical energy. Molecules, striking hard against each other, has heat energy. Air molecules, moving back and forth, have sound energy. Particles of matter called atoms, moving through the air, like ocean waves, known as phorons, have radiant energy. Examples are light, radio waves, x-rays, and so on. Tiny particles, known as electrons, found in all atoms, move rapidly through wires and have electrical energy. Protons and neutrons that are found at the center of atoms, move violently apart, and have nuclear or atomic energy. Different kinds of energy, as concluded by Einstein, are related to matter and to each other. The faster something moves, the greater its energy. Einstein showed that the highest speed is the speed of light and is about 186,300 miles per second. Therefore, the speed of light has the largest amount of energy.This energy can be found by multiplying the mass (in pounds) of the object by the square of the speed of light (186,300 times 186,300)
If a piece of matter moves at almost the speed of light, its energy must increase, and since matter and energy are similar, its mass will also increase. If its velocity equals the velocity of light, both its mass and energy become infinitely large and impossible to measure. Because of this, no object can travel with the speed of light, except light itself.
Einstein’s theory of relativity has illuminated the world of science and paved the way for other scientists to base their works on this theory. It has had as much influence on modern science as any other idea in the last three hundred years, especially in astronomy and atomic science.