Light is a form of energy. It is made up of electromagnetic waves. Some of the waves can be seen with the naked eye such as with a rainbow while others cannot be seen. The entire range of light is known as the electromagnetic spectrum.
The study of light is known as optics. Optics involves studying the behavior and properties of light along with its interaction with matter. Optics describes the behavior of visible, ultraviolet and infrared light. The first optic lens was developed by ancient Egyptians and Mesopotamians.
When you can see light, it is referred to as being “visible light.”
The properties of light are: (1) it travels in a straight line; (2) it can be reflected; (3) it can be absorbed; (4) it can be refracted; (5) it is a form of energy; and (6) it travels at a speed of 186,000 miles per second. That is faster than anything else man knows of.
The visible light spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. These include the colors red, orange, yellow, green, cyan, blue and violet.
All objects are capable of reflecting light. If they didn’t reflect at least some light, we would not be able to see them.
Laws of Light: Light behaves or reacts according to specific rules. For example, light always travels in a straight line.
Transparent objects, such as glass, allow nearly all of the light to pass through it.
Translucent objects will only allow some light to pass through it. An example of a translucent object would be tissue paper.
Reflection of light is when light hits a smooth surface. The surface does not absorb the light but bounces it off of its surface such as with a mirror. The angle of the bounced light will be equal to the angle in which the light first touched the surface. This is also known as the Law of Reflection which is defined as, the angle of incidence is equal to the angle of reflection.
Refraction of light is the process of light that bends as it passes from one object of a certain density or mass to another object with a different density or mass. The denser the material in which light travels through will slow the speed of the light. As an example, the density of water will slow down the speed of light.
