Light and How It Relates To Physics

Yamil Einar Asusta Santos

Light is a transverse, electromagnetic wave that can be seen by the human eye. Light is generally described by the measure of its wavelength in a vacuum. Light’s speed is also measured in a vacuum. Speed of light is measured in units of c, which is derived from the Latin, celeritas, which means swiftness. Colors of light are directly related to the light’s frequency. There are two main groups of light frequency colors.

The wavelength of light can be found by a formula that is inversely proportional to its frequency.  Although frequency is generally associated with light, frequency is the measure used for any wave phenomena. Possible wavelengths of late range from 400nm of violet light, and 700nm of red light. Polarization is a technique used to prove that light is transverse. During the early stages of study of light, light waves were first illustrated by experiments of interference and diffraction.

Light speed is a term used by many without even knowing how incredibly fast light travels. In a vacuum, light speed has been determined at a speed of 299,792,458 meters per second. It is important to note that the speed of light will always be slower in any medium, than it is in the vacuum. “In fact I have tried the experiment only at a short distance, less than a mile, from which I have not been able to ascertain with certainty whether the appearance of the opposite light was instantaneous or not; but if not instantaneous it is extraordinarily rapid.” (Galileo Galilei) Through modern technology and mathematics, science has taken great steps from trying to measure light by watching with a naked eye, turning on a lamp from a mile away, to simply plugging distance, time, wavelengths, frequency and type of light into an equation.

Although many have generalized light into six simple colors: orange, yellow, red, green, blue, and violet, there are in fact many types of light color. There are two major types of color of light. Monochromatic light can be described by simply one frequency while polychromatic light is described by several frequencies. Laser light, and the six simple colors are each monochromatic types of light specific to their own frequency. There are many more polychromatic light sources than there are monochromatic. An example of polychromatic light is white light. Light can also be non-visible, such as infrared light and ultraviolet light.

Since the early Greeks, the world’s population has been fascinated by light and it’s value to human life. Before modern science, it was not known whether light traveled at a finite speed, or if it was instantaneous. This was a hotly debated question until Rømer proved the finite speed of light. Before him, the first person to declare that light traveled at a finite speed was Empedocles. Even Aristotle did not believe him and said, "light is due to the presence of something, but it is not a movement". Light will continue to fascinate scientists all around the world, while they try to harness it’s power for improved energy efficiency and medial uses.