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How Does Light Dispersion Work?

29th Aug 2014

Have you ever wondered how light works? Being in the business of decorative lighting fixtures, we have a bit of a working knowledge of how light moves through your home and through your decorative light covers.

Light actually consists of billions of microscopic particles called photons, which are basically packets of energy that move at an incredibly high rate of speed (light travels at 186,000 miles per second). Given its incomprehensible movement, this is why it appears constant.

Light Dispersion

The process by which light enters a prism reveals its individual wavelengths. The white light we see is actually a combination of every color on the spectrum, which are only made visible when absorbed through a particular medium. The separation of light through a triangular prism is known as dispersion, and it works by splitting out the component colors blue, green, yellow, red, orange and violet.

The reason for the individualization is due to the varying light wave frequencies and how they interact and bend once inside the prism. The refraction of light inevitably reduces its speed. Denser pass-through materials cause light rays to slow down, whereas less dense material has the opposite effect. Each color has a specific wavelength that it follows, but again they are not visible to the naked eye until refraction occurs. This is what causes rainbows, whether in the sky or when light passes through your living room window at just the right angle.

The amount of bending in light dispersion is directly related to the varying wavelengths. Red has a long wavelength while violet is the shortest of the spectrum. While the dispersion of light occurs when it goes through any material, those that contain parallel entry and exit points (also known as interfaces), will make it appear as if nothing happened at all. This is because the reduction in speed that happens at first contact is equally reversed at the final interface, so the dispersion is completely countered.

If this was not the case, we would see all the colors of light everywhere we go. However, since prisms contain nonparallel interfaces, the result is constant dispersion, which is visible to the naked eye. The concept of light dispersion, whether in relation to decorative light covers or prisms, is not as confusing as it seems. We have carefully designed our decorative light panels to maximize light distribution without creating the rainbow effect.