The Study of Light - Types of Light

White Light: Technically white is not a color but the absence of color. However, white light in the study of light itself is actually what you get when you combine all of the colors that are visible within a light spectrum.

Combined, the multi-colors appear to be white but when the light is passed through a prism, the white light separates into the colors found in the visible light spectrum. These colors include red, orange, yellow, green, cyan, blue and violet.

A prism is a transparent optical element that has a polished flat surface that retracts or bends light.

Ultraviolet Light: Ultraviolet light is also frequently referred to as UV light. Ultraviolet means “beyond violet.” It is invisible to the human eye. It has a shorter wavelength but carries more energy than visible light. UV light can cause substances to emit a visible light known as florescence. UV light also stimulates the production of Vitamin D and can kill harmful microorganisms. Too much exposure to UV light can, however, cause sunburn and possible skin cancer.

X-rays: Light is made up of electromagnetic waves. X-rays are very high energy electromagnetic waves. In comparison, visible lights are medium energy electromagnetic waves. In addition, visible light cannot penetrate the human body but x-rays can penetrate the body. Because of this, x-rays are used widely in the medical field to help doctors see what is happening inside of the body. Finally, x-rays originate in the electron fields surrounding the nucleus of an atom.

Gamma-rays: Gamma-rays have the smallest wavelengths. They also have more energy than any other wave in the electromagnetic spectrum. They originate in the nucleus of an atom.

Infrared Light: Infrared light is a type of radiation that comes from the sun. Without infrared radiation, the Earth would not be able to sustain life.

Infrared light lies between visible lights and microwaves in the electromagnetic spectrum. It has different wavelengths ranging from those closest to visible light known as “near infrared” and those that are closer to microwaves known as “far infrared.” Humans are capable of feeling the far infrared wavelengths as heat. On the other hand, since the near infrared wavelengths are so small, the nerve receptions on the skin cannot detect them.

The infrared light is, perhaps, the most commonly discussed form of light within the electromagnetic spectrum. This kind of light is not visible to the human eye but can be seen through the use of special glasses and/or cameras. Infrared is so common that it is found in remote controls. It is also used to heat homes and to cook foods.