Light Primary Colors

Light is additive. This means that new colors are created by adding more lights of different colors until white light is created from all of the different colors. This concept is used in lighting for plays and concerts.

Separating Light

Prisms are transparent objects, usually made of glass, which can reflect light. "White" light hits the prism on one side moving at a certain speed. When the light goes through the solid material, however, the light is refracted so that light waves with different frequencies leave the prism at different angels; therefore, each separate color of the visible light spectrum is visible.

Rainbows- A Physics Example

The colors of the human visible light spectrum are those that comprise a rainbow, often abbreviated as ROY G. BIV (red, orange, yellow, green, blue, indigo, violet). Rainbows are created when light is reflected off of water and dust particles in the air.

Energy Per Photon

As the diagram from the last post suggested, the color red has the lowest frequency and violet has the highest frequency. This means that because of its shorter wavelength, violet has the most energy per photon, which makes sense since it is located closer to ultraviolet light (UV ray) on the electromagnetic spectrum.

Visible Light Spectrum

As we saw, visible light is only a fragment of the total electromagnetic spectrum. This is where we tie in our knowledge of wavelengths and frequencies: the human eye can only perceive light between 380 nm and 760 nm (400-790 terahertz). These, therefore, are the boundaries for the wavelengths and frequencies of light in the "visible light spectrum."

What You Can See and What You Can't

We cannot see all types of transverse waves. This is a result of the widely varying frequencies of the waves, only some of which the human eye can sense. All of the possible frequencies of the frequencies of electromagnetic radiation are listed as part of the electromagnetic spectrum, only part of which is comprised by visible light.

Frequency Implications

Frequencies are unique measurements of a wave. Waves with different frequencies either sound different (different pitches) or look different (i.e. different colors). For this reason it is very important for us to understand this quality of waves, as it can help us use them in more practical ways.

How Much in How Long

The wavelength of a wave helps determine a wave's frequency. Frequency, in this case, is defined as the number of cycles (1 cycle = 1 wavelength) of a wave that pass by a certain point in a certain amount of time (generally in cycles per second).

Wavelength

The wavelength of a wave is an extremely important and unique aspect because it helps to determine how that wave is perceived, as we will soon see. Wavelength is measured from crest to crest (or trough to trough) on a wave.