Human eyes chose at some point of evolution to detect three colours. And those colours were chosen for their importance and abundance, and the chances those colours gave them to differentiate visually things in their environment: * Blood. It's main component, hemoglobin, lets out a red wavelenght. Blood was important to see right away, and its light comes out from many animal skins also. Hemoglobin is the main oxygen transport molecule for most animal species. * Chlorophyl. Is essential for plant food production, and is the background colour of many sights humans (or apes) would encounter in their environments. So it was good to see that colour to sort out any other thing in front or behind leaves, that would most probably not be green. * Sky. Air scatters blue sunlight. The rest of the light is transmitted through the sky, and so comes down only in line with the sun, where as blue light is scattered throughout the sky and appears to come from all directions (though brightest near the sun). The blue sky would also be a frequent background, and like wise green, it would be an advantage to single out other things against a blue sky background. ...
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... supporting cruelty to animals and on GoVeg.com, I heard the meat can make people sick.Improperly stored or improperly prepared meat can cause illness, but meat itself is very good for you. Loaded with energy and protein, ounce for ounce meat provide... more
...s not a scientifically correct term. The things I want to pin down are those worm like shapes, floating in your field of view when unfocused. When you try to focus them, they move away. One explanation, I once heard is, that those are dust particles ... more
... atmosphere is responsible for the blue sky.This is attributable to the presence of nitrogen and oxygen molecules which are electromagnetically charged.Further,the dust and water particles adhering to... more
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...st, there is no such thing as "briefly describe" when you are talking about the liver. It has probably one of the most overlooked yet overworked functions in the body. You named a few. Besides helping... more
...like you're looking for the etymology of the word. It's from the greek word drys or drees which is the word for oak.http://ewonago.wordpress.com/2009/07/23/etymology of tree/http://www.etymonline.com... more
...I don't know and to tell the truth, I never noticed this phenomenon. I will speculate that the effect is the result of the way the raindrops disperse or scatter the light. Light on the outer edges... more