Nov 25, 2019 07:53 PM
It’s easy to understand how matter such as objects, paints, filters, etc. can absorb photons or for instance how a polaroid material can selectively absorb light from one plain, typically transmitting less than 1% through a sheet of polaroid, while transmitting more than 80% of light in the perpendicular plane. But when it comes to light itself, the subtractive theory of color, i.e. absorption, doesn’t make sense at all.
Excerpt from video--->Colour Mixing
You don't have to use a filter or colored filtered flashlights. You can see that the same thing applies when using just sunlight and a prism and we know that a prism doesn't absorb light. You can see that if you take the secondary colors (yellow, magenta, cyan), which some refer to as rays of shadows or Goethe spectrum vs. Newton spectrum, and try to isolate any one of them, they split into two primary colors. The cyan splits into blue and green. Magenta splits into red and blue and the yellow splits into red and green.
It’s common knowledge that when you mix red, blue and green together, you get white light. When you mix cyan, yellow and magenta, you get black. Yellow absorbs the blue light, magenta absorbs the green light and cyan absorbs the red light. With all the light absorbed, we see black. They say that white light minus blue, green and red light is no light at all, but technically the spectrum is still present, which is a little confusing. When it comes to light itself, what do they mean by absorbed because photons don’t absorb other photons?
From what I’ve read, it looks like photons don’t really cancel each other out either. Take the double slit experiment for example, destructive interference would violate the law of conservation of energy. It’s conserved in the superposition of waves. It’s not destroyed at the points of destructive interference and created at the points of constructive inference; it is redistributed in space. The energy is transferred from the region of destructive interference to the region of constructive interference.
So, when it comes to light, there’s really no absorption going on at all, right? Is this all just simply our biological perception of light?
Excerpt from video--->Colour Mixing
I’ve always had a problem with color mixing because I know that you can’t mix photons together. So, you can’t take a blue photon and a green photon and mix them together to get some other photon. That just doesn’t happen. Color mixing is definitely something that you can do. Well, actually, you can’t mix colors in physics, but you can do it in biology. It’s to do with how your eyes work. For example, if I shine red and green light into your eyes and overlap them, you will see yellow. If you mix two colors together, you get the color in between on the color spectrum. We can test that again by looking at green and blue together. If I mix green and blue, I get cyan and cyan is between blue and green on the spectrum. But why, why is that? Well, your eyes can’t measure the wavelength of light directly. Instead, you have these cone cells that are sensitive to the different parts of the spectrum. You’ve got red cones, blue cones and green cones. What about yellow? You don’t have a yellow cone. Yellow is close to red so your red cone fires a bit and yellow is close to green so your green cone fires. So, your brain is getting a message form your red and green cones at the same time and deciding that I must be looking at something in between those two colors then. So, that is brilliant because your brain is perceiving something about the world that it isn’t able to directly measure. But that does mean it can be tricked. So, what about magenta? Well, what should your brain do if your red cone fires and your blue cone fires but your green cone doesn’t fire? Does it do the same thing? Does it think I must be looking at something in between red and blue? But the color in between red and blue is green and you’re definitely not looking at something green because your green cone isn’t firing. So, in this situation, your brain invents a color. It makes up a color and that color is magenta. You don’t see magenta in the rainbow because it doesn’t have a wavelength.
You don't have to use a filter or colored filtered flashlights. You can see that the same thing applies when using just sunlight and a prism and we know that a prism doesn't absorb light. You can see that if you take the secondary colors (yellow, magenta, cyan), which some refer to as rays of shadows or Goethe spectrum vs. Newton spectrum, and try to isolate any one of them, they split into two primary colors. The cyan splits into blue and green. Magenta splits into red and blue and the yellow splits into red and green.
It’s common knowledge that when you mix red, blue and green together, you get white light. When you mix cyan, yellow and magenta, you get black. Yellow absorbs the blue light, magenta absorbs the green light and cyan absorbs the red light. With all the light absorbed, we see black. They say that white light minus blue, green and red light is no light at all, but technically the spectrum is still present, which is a little confusing. When it comes to light itself, what do they mean by absorbed because photons don’t absorb other photons?
From what I’ve read, it looks like photons don’t really cancel each other out either. Take the double slit experiment for example, destructive interference would violate the law of conservation of energy. It’s conserved in the superposition of waves. It’s not destroyed at the points of destructive interference and created at the points of constructive inference; it is redistributed in space. The energy is transferred from the region of destructive interference to the region of constructive interference.
So, when it comes to light, there’s really no absorption going on at all, right? Is this all just simply our biological perception of light?