January 23, 2021

Why is blue so rare in nature? Why didn’t ancient people “see” blue? And why does Japan’s blue look green to everyone else?

Videos from Half as Interesting, AsapSCIENCE, and It’s Okay To Be Smart


  1. The second video ends with, "Not only is our perception of the world an illusion, out brains are an active part of creating it." That seems quite overstated. Surely our vision is limited by the few types of color receptors in our eyes and by how our brain uses this limited information to distinguish a much larger range of colors. Thus, there can be illusions that fool our perception, but more often, we are able to perceive a reality of the world around us.

  2. Our brains give meaning to what it sees. There is a rare defect where people struggle with this. They have completely normal vision but they cannot meaning to it. So when shown a downtown skyline, they may say "Someone has taken shoe boxes and stocked them on end". The rest of us however see the trees in the foreground and other such clues and our brain can then determine that it is tall buildings that we are seeing. The brain does this for every moment of every day. Can the brain be fooled at times by taking advantage of some of the short cuts it makes to make these rapid fire decisions? Similarly a normal film camera only captures so many frames a second as that is only what is needed for movement to appear smooth to humans.