Three Important Corporate Lessons:

Lesson Number One:
A crow was sitting on a tree, doing nothing all day. A small rabbit saw the crow, and asked him, "Can I also sit like you and do nothing all day long?" The crow answered: "Sure, why not." So, the rabbit sat on the ground below the crow, and rested. All of a sudden, a fox appeared, jumped on the rabbit and ate it.
Moral of the story:
To be sitting and doing nothing, you must be sitting very, very high up.


Lesson Number Two:
A turkey was chatting with a bull. "I would love to be able to get to the top of that tree," sighed the turkey, "but I haven't got the energy." "Well, why don't you nibble on some of my droppings?" replied the bull. "They're packed with nutrients." The turkey pecked at a lump of dung and found that it actually gave him enough strength to reach the first branch of the tree. The next day, after eating some more dung, he reached the second branch. Finally after a fortnight, there he was proudly perched at the top of the tree. Soon he was promptly spotted by a farmer, who shot the turkey out of the tree.
Moral of the story:
Bullshit might get you to the top, but it won't keep you there.


Lesson Number Three:
A little bird was flying south for the winter. It was so cold, the bird froze and fell to the ground in a large field. While it was lying there, a cow came by and dropped some dung on it. As the frozen bird lay there in the pile of cow dung, it began to realize how warm it was. The dung was actually thawing him out!
He lay there all warm and happy, and soon began to sing for joy. A passing cat heard the bird singing and came to investigate. Following the sound, the cat discovered the bird under the pile of cow dung, and promptly dug him out and ate him!
Morals of this story:
(1) Not everyone who drops shit on you is your enemy.
(2) Not everyone who gets you out of shit is your friend.
(3) And when you're in deep shit, keep your mouth shut

Same Colours

Why does the illusion work?

The visual system needs to determine the color of objects in the world. In this case the problem is to determine the gray shade of the checks on the floor. Just measuring the light coming from a surface (the luminance) is not enough: a cast shadow will dim a surface, so that a white surface in shadow may be reflecting less light than a black surface in full light. The visual system uses several tricks to determine where the shadows are and how to compensate for them, in order to determine the shade of gray "paint" that belongs to the surface.

The first trick is based on local contrast. In shadow or not, a check that is lighter than its neighboring checks is probably lighter than average, and vice versa. In the figure, the light check in shadow is surrounded by darker checks. Thus, even though the check is physically dark, it is light when compared to its neighbors. The dark checks outside the shadow, conversely, are surrounded by lighter checks, so they look dark by comparison.
A second trick is based on the fact that shadows often have soft edges, while paint boundaries (like the checks) often have sharp edges. The visual system tends to ignore gradual changes in light level, so that it can determine the color of the surfaces without being misled by shadows. In this figure, the shadow looks like a shadow, both because it is fuzzy and because the shadow casting object is visible.

The "paintness" of the checks is aided by the form of the "X-junctions" formed by 4 abutting checks. This type of junction is usually a signal that all the edges should be interpreted as changes in surface color rather than in terms of shadows or lighting.
As with many so-called illusions, this effect really demonstrates the success rather than the failure of the visual system. The visual system is not very good at being a physical light meter, but that is not its purpose. The important task is to break the image information down into meaningful components, and thereby perceive the nature of the objects in view.