Color constancy is the problem of how we see various shades of one color as really of one color. For instance, we see a ping pong ball as white, when it is really a gradation of shades of gray--a painter would have to use dark pigments to paint a ping pong ball as a spherical object.
Here's another example, where the A square looks darker than the B square:
The A square and B square look like they are different shades in the checkerboard above, but in the checkerboard below, they are shown to be the same shade.
This suggests that the shade of the chalkboard that we see is in fact different from what we really see. Of course, this does not amount to saying that the chalkboard is not green, but rather a different shade of green that what we seem to experience.
The Lilac Illusion however, produces an experience of green occurs from a gray experience, where there is no green to be experienced. This, coupled with the shade illusion above, suggests that perhaps the color of the Chalkboard is other than what we experience.
The perception of green in the lilac illusion is only possible with the disappearance of the lilac dots, because lilac and green are complements on the color wheel. It's the same as when you stare at something blue for a long time and look quickly at a white wall - the eye perceives orange because, again, blue and orange are complements. So unless you want to argue that the chalkboard is blinking lilac... which you probably will, and good luck with that if you do... I remain unconvinced.
ReplyDeleteGood point mandemonium.
ReplyDeleteWhat if, though, the way your brain correlated the experience of colors with reflectance wavelengths was "complementary" (i.e. opposite) to mine? So, when the "Green" (i.e. 510 nm wavelengths) of the chalkboard is seen by you, it is experienced as a lilac color, a color which you still call "green". This is called the "problem of the inverted spectrum".
I've often wondered about that - I mean, if different people perceive the same color in different ways.
ReplyDeleteBut regardless of how we experience it, the chalkboard has a true color and everyone has agreed that it is "green," no matter if they're seeing your interpretation of green, or lilac, or neon orange, for that matter. Green is not actually a color, but just a name that people have given to an experience.
And BY THE WAY, why does YOUR perception of the chalkboard have to be the right one, hmm???
Don't forget that when you look at a chalkboard, you're not just getting a single unit of light; you're getting a whole lot of little photons that are bouncing around interacting with various electrons and elements in the chalkboard. What you perceive as green is really just the average of a whole lot of colors.
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