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Science project idea on why objects have different colors.
Color Science Project Idea
Why objects have different colors.If we see the various things around us by reflected light, is it not rather surprising that they should have different colors?The light which comes from one book affects the nerve endings in the eye in such a way that it carries a message to the brain which gives us a sensation of red; the light from a book beside it may give us the sensation of green.The light striking the books must be the same, for if we put the red book where the green one was, it still continues to be red.Apparently, therefore, the object from which light is reflected causes a change which gives rise to the color. Another illustration of the production of color by light is the color seen at sunset and sunrise.What colors have you seen on these occasions?Have you ever seen the colors in water spray when looked at from certain positions, or colors along the edge of broken glass?What are the colors of the rainbow? These observations all indicate that ordinary light, which we call white light, may be broken up into various colors.The truth of this may be shown by the following experiment.
Color Science Experiment
Darken the room.Place a glass prism in such a position that a beam of sunlight admitted through a small opening will pass through it.What do you observe on the opposite wall? This experiment shows that white light is really a combination of the colors that are seen in the rainbow.We are now ready to understand why not all objects are white.When light strikes the wall, for example, a portion of it is absorbed, and a portion of it is reflected.You have noticed that some walls reflect more light than others.The cover of a green book reflects only that part of the white light which gives us the sensation of green; a red book, on the other hand, absorbs all the light except the part which gives us the sensation of red. The white paper of this page reflects almost all of the light which strikes it, but the black letters absorb practically all the light which strikes them.A piece of red glass allows only red rays to pass through; all of the others being absorbed or in some cases partially reflected. Since the absorbed light is changed into heat, explain why light-colored clothing is more comfortable in the summer and in the tropics, and dark-colored clothing is preferred for winter wear.Explain why the colors of objects may not be the same in artificial light as in sunlight.This can be shown in an extreme form by comparing the colors of a number of pieces of paper or cloth when observed first by sunlight, and then by a candle in which is held a glass rod which has been dipped in common salt solution.
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