Physics is a huge part of our life that we are oftentimes unaware of. For example, people all around the world appreciate rainbows, but a small fraction of these people are able to explain why rainbows are the way they are. Many of the physics principles we have learned this year can help explain why rainbows look the way they do.
The first principle is refraction. Refraction is something we have previously learned as bending light. This bending of light occurs because light can change speed. The speed of light in a certain media is always constant, but changes as the media changes. So as the light changes media it has to bend to accommodate for the different speed it is traveling. As the light changes from raindrops to air it undergoes refraction. Different colors refract at different angles.
The next component to understanding rainbows is the idea of white light. White light is something that we see everyday. However what we cannot see without proper tools is that white light can be broken down into all wavelengths of visible light. Basically when white light is separated, one can see that it is in actuality a mixture of all the different light types. The mixture would be a spectrum of all the different colors. A prism would be one such device that could break white light down into different spectrums. A raindrop can act as such a prism, dividing white light into different wavelengths. These wavelengths are ROYGBIV, or red, orange, yellow, green, blue, indigo and violet.
The next part of a rainbow to analyze is the way in which the colors fall. First of all the raindrops do not actually reflect mini rainbows that combine into one large rainbow. Each raindrop reflects a different single color because one raindrop would be far too small to reflect an entire rainbow. The raindrops that are located lower in the sky portray blue and greenish light, while the drops in the higher sky make up the red and yellow light. Because the single droplets do not make up the rainbow, there has to be something else to contribute to the entire rainbow picture. This is where the antisolar point comes in. It is the point that is 180 degrees away from the sun. This is essential to determining rainbows, more importantly where rainbows are in the sky. Along the antisolar line is also where the light that is being broken apart will be getting reflected. For one example red light gets reflected back at 42 degrees while blue light gets reflected back at only 40 degrees. This helps us understand rainbows because of how the colors are organized. The color red is placed on top for specific reasons. Each color of light has a different frequency, and when combined they form white light. But when separate each color is independent in terms of frequency and speeds. At different frequencies they refract in different ways as represented by the rainbow. Evidently these different concepts of everyday physics make something seen by all, able to be also understood by all.
Another miracle of everyday life are mirages. However they are not in fact miracles, because they after all can be explained by physics. Mirages rely primarily on refractions. Mirages can occur where different types of air congregate. As these different medias can congregate, refraction can be ongoing. And this refraction can produce the illusion of an image. This refraction occurs when the air near the bottom of the floor is a different temperature. So that this can be refracted at the boundary between the temperature difference, and then light from the sky will be reflected onto the floor. A mirage can also happen when there is a temperature difference in the air. Then in this case, with the right type of boundary, the image will be magnified in the distance. Mirages have fascinated people, because often times it is more interesting to believe in something else than a scientific explanation. Refractions of light in the sky can even account for some of the UFO spotting that occur around the world. Obviously these different types of mirages can occur and they can each be explained by something in physics.
Lastly the power of light refraction can help us explain some of the most widely acknowledged beauties of the world- sunsets and sunrises. People travel all around the world to find areas where the sunset or the sunrises are beautiful. However far fewer people are really interested in the physics behind these phenomena’s. They can be explained through the manner in which the eye works. The sun rays have to travel through several different parts of the universe and atmosphere before they reach our eyes. And as they travel through these parts they are refracted and broken down into the colors our eyes see. However the blue light is almost never seen due in part to the vast number of ways it refracts and how our lens works. If we use physics we can understand some of the most profound beauties of the world.
Bibliography
Metz, Dan. "How Rainbows Work." How Stuff Works. 2008. How Stuff Works. 2 Mar 2008
Gache , Gabriel. "How Mirages Work." How To. 14 12 2007. How To. 2 Mar 2008
Rayne, Edward. "Why does the red color appear at the horizon during sunset?." Physics and Astronomy Online. 2 Mar 2008
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