Evaluation on Color (october 12)

(This is the evaluation, which I had technical difficulties with.)

Hello Professor,

Thank you for the meeting today. It was very enjoyable. I am sorry that it was cut short but I had class at 2:20 pm.

The internet is not allowing, the "New Post" window to be opened so I am sending you the fourth evaluation through this medium. Thank you for understanding.

I am writing the blog today because yesterday night, I got carried away by my research. One thing led me to another and then it was too late. Anyways, I hope it is still ok.

         I chose to investigate further on the concept of color, that was dealt with this week on the lab, for it is a subject that has always intrigued me. As I was doing my research, I was hoping to find answer what color really is. The best definition that I was found was on The Illusion Theory of Colors in the Stanford Encyclopedia of Philosophy. "Colors conceptualized as objective, perceiver-independent, intrinsic feature of physical bodies are properties not found in nature. The colors in objects which we represented as them having, are ones that no object actually has." This definition basically states that colors are not the universal and objective elements that we are taught in elementary school, rather they are the synaptical interpretation of a phenomena physics. 

The physical phenomenon that constitutes color is really fascinating.  In ancient times it was believed taht the purest form of light was "white" light. Yet during the Enlightment period, Rene Descartes started notticing that the colors present in the rainbow where the same ones that were produced at the edge of a glass. Consequently, he concluded through mathematical analysis that those colors were produced by the refraction of light. Yet is was Isaac Newton who discovered that it was not the "white" light that produced the colors in the rainbow but rather that the colors were composing the "white and pure" light. Newton arrived at this conclusion by letting a ray, in a darkened room, go through a prism.  As a result red, orange,yellow, green, blue, and violet appeared on the screen. The reason for the colors being portrayed on the screen, was the way in which the prism caused the light to be refracted or "broken" into various different angles. To prove that "white" light really consisted out of those six colors, he introduced a second prism in his experiment, which was placed in front of the first one. As he predicted, the light visible on the screen was the "white" one.  The second prism re-refracted or "mended" the light that had been "broken" by the first prism. It cancelled the effect of the first one like a ordinary sheet of glass does. So, when we detect a red glass it due to the fact that only the lightwave that constitutes the color red is able to pass through. All the other components of light have then been absorbed by chemicals present in the glass. 

         Yet how are we able to see the redness of the glass? As the wavelenght of the color red passes through the glass, it activates one of the light sensitive cells present in our retina. It is believed that we have three different light sensitive cells: red, green, and blue. Other colors are not necessary for different combinations of those base colors can bring about all the colors of the light spectrum. This theory was established by Thomas Young and amplified by Herman Ludwig Ferdinand von Helmholtz. As a result this theory is known as the Young-Helmholtz- Theory of Color. So the color purple is the result of the blue and red light cells being activated. And white light is the result of blue, green, and red being activated equally. 

         Color is then a composition of our brains interpretation of  a physical phenomenon. Do you then see the same green, as I do?? 

 

 

 

Bibliography:

Understanding Physics by Isaac Asimov

The Stanford Encyclopedia of Philosophy

Spektrum Lehrbuch Biologie