Analytic Essay

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We designed this project in order to further extend our knowledge of how light is absorbed in water, and more specifically, how colors are altered at different depths. In our hypothesis, we predicted that red would be the first to decrease because it has the longest light waves. We thought that yellow would follow, and then blue. We made this hypothesis using our knowledge of the length of the wavelengths. However, contrary to our hypothesis, the yellow decreased just as fast as the red until the very end, at 15ft. Another major thing we noticed in our results that differed from our hypothesis was how much the saturation of the colors decreased. I think we did not realize at the time that we made our hypothesis how easily the light waves are absorbed into the water. We feel that overall our experiment did a good job at helping us to learn more about color absorption. However, in the experiment there were a few problems that occurred.

One problem we faced was the bottom of the pool in which we were conducting our experiment was white. Because the bottom of the pool was white, the light waves that were not yet absorbed were reflected off the bottom of the pool and put back into the water. This caused the colors to be more saturated than they would have been normally. The results most likely affected from this are the fifteen-foot pictures. This is because they were taken closest to the bottom of the pool where the light waves could be easily reflected. However, this did not seem to affect our results too badly, because the saturation of the colors at fifteen-feet was still less then the saturation of the colors at ten-feet. One reason for this is that many light waves have already been absorbed at fifteen-feet, more so than at ten feet. This means that even though the light waves are more easily reflected there are less light waves to be reflected. To fix this for future experiments we would conduct our experiment in a black-bottomed pool, preferably, one with greater depth.

Another difficulty we had was in finding the saturation from the pictures we took, which actually turned into two problems. When pictures are scanned into computers they appear as lots of little dots, otherwise known as pixels, these dots make up the picture. We planned to "eye drop" the pictures, which, after a few steps, would tell the saturation of the color in the picture. The problem with this was, the "eye drop" would only tell us the saturation of one pixel at a time. And one color could be made out of thousands of slightly different colored pixels. What we did was take the saturation of the pixel that seemed like it was the average color. What we could have done was take the saturation of every single pixel in the picture and taken the average saturation as the result. However, this would have been so time consuming, as hundreds and hundreds of pixels make up one picture, that we settled for the majority saturation.

As the yellow picture was bought deeper in the water, we noticed that it started to turn green (if you go to the display of results page you can see the actual photographs and you should notice this). We explain this by the fact that yellow and blue make green. As we looked through the water, the blue of the water was mixed with the yellow of the paper. As we took the yellow down deeper into the water there was more was more water around us to make the yellow seem greener. In our hypothesis, we predicted that the yellow's saturation would be in-between the blue and red's saturation. However, it was very close to the red's saturation, much closer than it was to the blue's. It lost its saturation much faster than we expected. As you have read in the background essay, a nanometer is one millionth of a meter. Also, in clear water the longer the light wave, the faster it is absorbed. The yellow's light wave is about 600 nanometers, the blue's is somewhere in-between 400 and 500 nanometers, and the red's is a little more than 700 nanometers. So one reason the yellow's saturation is closer to the red's is because its light wave's length is closer to the red's. Another reason it might have been affected is because of the green tint in the yellow's pictures. This may have affected our results by causing the saturation to look stronger.

Something that was not a problem, but we would have liked to explore it if given the time, would be conducting our experiment in different environments. In clear water, such as a pool, red wavelengths are the first to be absorbed, orange comes next, followed by yellow, green, blue, and then purple. Meanwhile, in other waters, particularly coastal waters, there is plant material, animal material and pollution that add to specific absorption. For example, plankton absorbs violets and blues. So, although in the pool the blue color lost the least amount of saturation, it might be the fastest to be absorbed in an environment with plankton. So what we wanted to do was conduct our experiment, not only in the pool, but in a river, pond and ocean too.

Despite, all the problems that occurred while we were completing our project, we believe that overall, the experiment showed the fundamentals we wanted to prove. It showed the color absorption patterns of clear water. Although, there are numerous things we would change, if given the chance to repeat our experiment, we feel that, all in all, our experiment was a success.

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