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Visible Light Wavelength - What is light? How we distinguish diff colors? Why some colors stronger

Hello my fellow earthlings!

Have you ever wondered what is light? How our eyes and brains are able to see and distinguish different colors? Also, why do some colors overpower others even though they have the same intensity? Well have no fear because are going to explain this everyday process so that it's crystal clear.

First, lets go over what exactly is visible light. Visible light is just another form of electromagnetic radiation that's visible to most human eyes. It contains red, orange, yellow, green, blue, indigo and violet. Every other color we perceive is just a mixture of those seven. Here's the interesting part. Objects we see don't actually have color, instead they give off reflected light that has different wavelengths, frequencies and energy. Our eyes then use these special cells called cones which acts as photoreceptors to measure the different wavelengths of colors and then transports that data to the cortex of the brain to process the wavelength and return a color for us to enjoy. Technically, it is possible that we all see colors differently, for example your best friend could see green differently than you.

Now that we have the basics, lets go into a little more detail about the wavelength, frequencies and energies of these lights that our eyes and brains process. This will explain why some colors are more dominant than others and why other colors can change based on temperature. Take a quick look below and at figure 1.


Figure 1

For this article we are only going to be focusing on the visible light inside the brackets. Anything outside the brackets like the IR and UV can't be detected by the human eye but can potentially be harmful. In figure 1 above, notice the directions the frequency, energy and wavelengths are pointing. If you analyze you'll realize red has larger wavelength than the rest of the colors but also the smallest energy and frequency. Therefore the color violet has the largest frequency and energy but the smallest wavelength. The wavelength defines which colors are the most dominant. So therefore which colors first and second most dominant? You guessed it! Red and orange. And which color is the least dominant? Violet.

So you may wondering what is a wavelength? See figure 2 below.


Figure 2

Each color has different sizes in wavelengths measure in nm(nanometers or 1*10^-9m) that define their dominance. And as stated above, these wavelengths and frequencies seen below are what the cone cells in the human eye are measuring for the brain to process. See figure 3 below.

Figure 3

By looking at figure 3 we can see how the frequencies and wavelengths are different. Remember violet at the top has the high frequency but shortest wavelength and red at the bottom has the lowest frequency but longest wavelength. So what about energy? It's simple, energy is what drives the light all around us and reflects off all objects for our eyes and brains to process. So at night the reason it's harder to see color is because there's less light energy to bounce off the objects you're looking at, therefore you mostly see black. And we all know black is the absence of color. Light energy can be calculated by using equation 1 below.


Equation 1


In physics, there are so many different equations to calculate energy for different applications. There's chemical energy, kinetic energy, thermo energy, radiation energy, the list goes on. However, the only energy we are interested in is light energy and equation above is how you calculate it.

I was going to go to into temperature and why some colors change based on temperature but that would lead this article to being twice as long.

Here's a fun fact. Women are often more attracted to guys who wear red because it exerts it's dominance. And if you're nerd you can say that women are more attracted to longer wavelengths.

Anyways that concludes this article. In another article I will go into white and black with white being make of all colors and black being the absence of color and why one absorbs less heat than the other. I hope you enjoyed reading this article and stay tuned for more! Don't hesitate to subscribe!


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