What Is Refraction?

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What Is Refraction?

Refraction is the bending of light through a transparent material. The loss of light speed and the path light takes are both factors of refraction. To better understand refraction, you must consider some of the lessons learned in Chapter 1. You learned that light travels at 300,000 kilometers per second. If light interacts with a transparent surfacefor example water, a prism, or glassit loses speed. This interaction causes the light to bend a little before it leaves the transparent material. This bending of the light is refraction . Refraction mostly occurs when light changes from one medium to another; for example, from air to water. To better understand the bending effect in water, look at Figure 3.8.

Figure 3.8. An example of refraction of a straw,which is submerged in a glass of water.

Figure 3.8 shows how refraction works. Because the light bends when it changes mediums, the straw in Figure 3.8 appears closer than it really is in the water. This is the nature of refraction, for it bends to travel the least amount of time. The angle of incident is much larger than the angle of refraction. You must take this angle into account when you write your computer refraction function. This is sometimes called the index of refraction . Look at the example of the angle (or index) of refraction in Figure 3.9.

Figure 3.9. Index of refrac tion.

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