Light is the most widely used form of energy on Earth.

Not in terms of electricity production, but in terms of sheer usefulness. All plants on earth make use of light, and all humanity is in turn dependent upon these plants. But, beyond the greater concept of the Sun's light, humanity as whole species cannot function with the illumination of light. In this context, we're of course discussing artificial light. To many people artificial lights are all the same. Maybe some people recognize the subtle differences in color and power of the lights, but a large number of people can't tell the difference. The world of lighting and devices that produce artificial light are rather diverse. From incandescent lights to fluorescent lights, there is a wide variety in the power and color that different types of lights and bulbs emit. We're not just talking different levels of brightness. There is a whole range of possibilities with regard to the specific color of light. Light itself is the only visible form of radiant energy. Radiant energy is energy with out the use of a physical medium. For example light can travel readily through space, whereas sound cannot because there is no air to carry the sound wave. Radiant energy is broken down into its various types and placed on a scale called the Electromagnetic Spectrum. On this spectrum you'll find all sorts of energy, Microwave, X-Rays, Ultra Violet Light, heat or infrared, radio waves, etc. This spectrum is a measurement of wavelength. If you were too look at radiant energy as it passed by, it would be just like looking at waves on the surface of the water, up and down, up and down. Each different type of radiant energy has waves of different lengths. Some are short, some are long. The light we humans can see with our eyes falls roughly in the middle of the spectrum. But, light occupies a narrow wavelength in the spectrum. Each color itself has a different wavelength, violet beginning at 380 nanometers, to red ending at 760 nanometers. Unlike mixing paint, viewing a full and equal balance of all these wavelengths presents a viewer with the color white. A total absence of visible light is obviously the opposite of white, black. Visible light itself is actually invisible. Confused? Visible light is a sort of an information relay. It bounces off the surface of physical materials and carries the color to our eyes, where it is interpreted and gives us the perception of the world around us we're used to. This is where the understanding of light becomes useful in the home. Homeowners must be keenly aware of the type of light bulbs they purchase because each one emits a different wavelength of light. One bulb might emit a shade of off white, while one might be noticeably yellow. In fact only small minority of light bulbs actually produces true white light. Having an understanding of how color is produced and how it renders in the home will improved a homeowner's ability to control the mood and intended look and feel of their home.