What Is The Electromagnetic Spectrum?

    Published: 06-16-2009
    Views: 12,639
    Science expert Emerald Robinson explains what the electromagnetic spectrum is.

    Emerald Robinson: Hi! I am Emerald Robin in this What is Video we are going to take a closer look at the electromagnetic spectrum.

    What we see as light is only a small part of the electromagnetic spectrum. Electromagnetic spectrum refers to the many types of radiation released from stars including our own sun.

    Electromagnetic radiation travels in waves. Frequency described how many waves per second a wave length produces. Wavelength measures the length of an individual wave in meters. Scientist describes the electromagnetic spectrum as a long line. At one end lie radio waves with the longest wavelength and lowest frequencies in the spectrum. A single radio wave had the length of a football field.

    After radio wave, come microwaves which produce more energy due to shorter wavelengths and higher frequencies. Cellphones, radar, and microwave ovens use microwaves. Next comes infrared light, the sun, fire, living creatures, and other heat sources all produce infrared light. While we cannot see infrared light, we feel it as heat.

    Visible light occupies a narrow slight of the electromagnetic spectrum nestled between infrared and ultraviolet light. Red wavelengths have the lowest frequencies and longest wavelengths of visible light. As you move from red through orange, yellow, green, blue, and finally violate, wavelengths shorten and frequencies increase.

    From visible violet light, we move into ultraviolet frequencies. Human skin produces vitamin-D when exposed to ultraviolet light. But excessive ultraviolet light causes sunburns.

    Next X-Rays, which pass through soft tissue, but not denser materials such as bone, making them valuable for medical test. X-Rays also has security applications such as airport baggage checks. Gamma rays produce even shorter wavelengths, higher frequencies and more energy. In comparison to the football field size wavelengths of radio waves, gamma ray wavelengths are small as atom nuclei.