It can be highly destructive yet is utterly necessary for life. For astronomers, it's by far the most important way of unlocking the secrets of the cosmos. We know it best as light. But the light we see with our eyes is just a tiny sliver of a vast electromagnetic spectrum produced by everything from comets to quasars. All these different forms of light are fundamentally the same thing.
Scientists now know that light can be described as a train of waves that carries energy.
These waves are in fact the universe's principal means for transmitting energy. Unlike water and sound waves, however, light does not need a substance through which to travel. The different kinds of light are waves that have different lengths between consecutive crests or troughs. Energy Carriers Visible light and its cousins are not equal-opportunity carriers of energy. Besides being viewed as waves, light can also be viewed as consisting of massless particles known as photons.