Contrasting illusions. Color illusion

Our vision can very easily deceive our brain with simple color illusions that surround us everywhere. Some of these illusions await you further.

How many colors are there in the picture?

Blue and green spirals are actually the same color - green. Blue color not here.

The brown square in the center of the top edge and the “orange” square in the center of the front edge are the same color.

Look carefully at the board. What color are cells “A” and “B”? Does “A” seem to be black and “B” white? The correct answer is below.

Cells “B” and “A” are the same color. Gray.

Does the lower part of the figure seem lighter? Use your finger to cover the horizontal border between the top and bottom of the shape.

See chessboard with black and white cells? The gray halves of black and white cells are the same shade. Gray color is perceived either as black or as white.

The horse figures have the same color.

How many colors are there, not counting white? 3? 4? In fact, there are only two - pink and green.

What color are the squares here? Only green and Pink colour.

Optical illusion

We look at the dot, and the gray stripe on the orange background becomes... blue.

In place of the disappearing purple spots, a green spot appears, moving in a circle. But in reality it doesn’t exist! And if you concentrate on the cross, the purple spots disappear.

If you look closely at a point in the center of a black and white image for 15 seconds, the picture takes on color.

Look at the center of the black dot for 15 seconds. The image will turn into color.

Look at the 4 dots in the center of the picture for 30 seconds, then move your gaze to the ceiling and blink. What did you see?

At the intersections of all white stripes, with the exception of the intersection at which you fix your gaze this moment, small black spots are visible that are not really there.

Disappearance

If you look closely at the dot in the center for a few seconds, the gray background will disappear.

Concentrate your gaze on the center of the picture. After some time, the blurry colored images will disappear and turn into a solid White background.

Remember the Irish tales about leprechauns guarding pots of gold where the rainbow “ends”?

It turns out that a rainbow exists only in our perception - in reality it does not exist.
This is why it is impossible to find the ends of the rainbow. And that’s why leprechauns are gold :)
Why is that? Welcome to the cat... Special greetings lora_in for your curiosity :)

Rainbow- an atmospheric, optical and meteorological phenomenon observed when the Sun (sometimes the Moon) illuminates many water drops (rain or fog). A rainbow looks like a multi-colored arc or circle made up of the colors of the spectrum (from the outer edge: red, orange, yellow, green, blue, indigo, violet). These are the seven colors that are customarily identified in the rainbow in Russian culture, but it should be borne in mind that in fact the spectrum is continuous, and its colors smoothly transition into each other through many intermediate shades.

The center of the circle described by a rainbow lies on a straight line passing through the observer and the Sun, moreover, when observing a rainbow (unlike a halo), the Sun is always behind the observer, and it is impossible to simultaneously see the Sun and the rainbow without the use of optical devices. For an observer on the ground, a rainbow usually looks like an arc, part of a circle, and the higher the observation point, the more complete it is (from a mountain or an airplane you can see a full circle). When the Sun rises above 42 degrees above the horizon, a rainbow is not visible from the Earth's surface.

And now the most interesting...

Incredibly, there is no color in the world around us. Color is just an illusion created by the brain and does not exist in physical reality.

Look around you. From birth you are surrounded by an illusion, “additional reality”, which is so familiar that, like air, it is completely invisible to us.

For example, a person shows a rainbow as if only to himself: its existence is associated with the characteristics human vision and depends on the cone-shaped photoreceptors in the eyes - for other living creatures that do not have similar cone-cones, the rainbow does not exist at all. So you're not just looking at a rainbow—you're creating one.

You can read more about the structure of the retina.

Let's give the floor to Erwin Schrödinger, Nobel laureate in physics, one of the creators of quantum mechanics, better known to the general public thanks to one cat: “If you ask a physicist what yellow light is in his understanding, he will answer you that these are transverse electromagnetic waves, whose length is approximately 590 nanometers (nm). If you ask him: “Where is the yellow?”, he will answer: “It’s not there at all in my picture, but when these vibrations hit the retina of a healthy eye, the person who owns that eye experiences a sensation of yellow.” "

However, the sensation of color cannot be explained within the framework of the objective picture of light waves that physicists have. Proof of this is visual illusions, colorful dreams with eyes closed and people who are able to see color with other senses.

Optical illusion

Visual illusions reveal some aspects of how vision works. If you look closely at a point in the center of a black and white image for 15 seconds, the picture takes on color.

Let's look at another illusion. In Russian it is called “running light green circle”, in English it sounds like “lilac hunter”. It is based on the Troxler effect.

What's unusual here? A moment later, in place of the disappearing purple spots, a green spot appears, moving in a circle. But in reality it doesn’t exist! Electromagnetic waves from the spectral range of 500-565 nanometers do not physically reach the retina of the human eye. This is as unusual as if we heard the melody of a song without any sound vibrations reaching the eardrum. And if you concentrate on the cross, the purple spots disappear completely.

Here's a still frame from the GIF above that captures the reality. Only the purple circles are physically present. There is no green in any of the frames. This is another confirmation of the non-physical nature of color. Moreover, when we see colored dreams, our eyes are generally closed.

Concentrate your gaze on the center of the picture. After a while, the blurry color images will disappear and turn into a solid white background. The picture is not a gif. Here, on the contrary, electromagnetic waves responsible for colors enter our eyes, but we stop seeing colors.

If you look at the central tile of the cube at the top and on the side facing us, you can see that in the first case it has Brown color, and in the second - orange. This is our perception of reality. But the physical reality is that these two tiles are the same color.

Colored numbers

“I told my father: I realized that in order to write the letter “R”, all I have to do is first write “P” and then draw a line down from its loop. And I was so surprised that I could turn a yellow letter into an orange letter just by adding a line!” — wrote Patricia Lyn Duffy, writer and synesthetic.

In some people, irritation of one sense organ causes both sensations specific to it and sensations corresponding to another sense organ. This phenomenon is called synesthesia, which is translated from Greek as “shared feeling.” That is, a person can look at moving pictures and still hear sound. Or for it, each number or letter can have its own color, as in the picture below. Colored numbers are the most common type of synesthesia. By the way, I wonder what Patricia will see if her orange “R” is written in light green ink?

That is, it is not at all necessary that color be associated with a specific electromagnetic wavelength. Color can be generated by sound vibrations, and sound, for example, by a certain animation.

Nobel laureate in physics Richard Feynman said: “When I see equations, I see letters in color - I don’t know why.” He was also a synesthete.

James Wannerton has a taste for words. New York tastes like a boiled egg to him, and London tastes like mashed potatoes. And the other man, McAllister, sees the music. The areas responsible for hearing and vision react to sound. It is amazing that he has been blind since the age of 12: “When I hear music, colorful flashes appear before my eyes, it seems to me that I see even more beautiful flowers than sighted people."

And in order to check whether people are lying and whether they are crazy, tests such as those in the figure below have been developed. There are many fives and twos printed on the piece of paper. A common person Looks for two for a relatively long time, for him all the numbers look the same. A synesthete does not need time to look at each number. He immediately sees the red pyramid formed by the twos.

Phenomenon of color

Scientists conducted experiments on the perception of artificial neural networks(INS) illusions. The perception of illumination of the selected point depended on the surrounding structure, on the context in which it was located. Also, the formation of the illusion was influenced by previous experience and stereotypical perception. For example, people see a face as convex, not only when it is actually convex, but also when it is the reverse part of a mask, that is, a figure concave inward.

We live in our own information reality. Color is just an illusion created by the brain and does not exist in physical reality. Depending on expectations, context, and mental models, the brain can arbitrarily change the colors of objects. Which would be hard to imagine if color were a real physical phenomenon.

Colors are a specific form of language. When we see one color, we see something vague, dependent, something like one word in a language. The interpretation of this “word” occurs if we place it in a “sentence” and its context. And electromagnetic waves are, apparently, entities presented to us in two forms: existential, as part of physical reality, and denotative, like ink spots on paper, formed into configurations that are meaningful to us, words that have meanings, as part of information reality.

By the way, even if the nature of color in our consciousness is revealed, the question arises: why are the colors exactly the way we see them? Is this due to our structure or was it, perhaps, somehow randomly chosen during evolution, just as these and not other letters were chosen for the alphabet by chance? What is it like to see the world in ultraviolet or gamma?

It also follows from this that our world, apparently, is not only colorless, but also silent. And to the question, can you hear the sound of a falling tree in the forest if no one is nearby, you can give an answer. No, I can't hear it. Physics is preserved. The tree falls, air vibrations spread. But the sound is born in the brain of the observer.

Zen koan about "What does one hand clap sound like?"now takes on a very interesting meaning :)

And one more thing - is Schrödinger's poor cat alive or dead? :)

Variations in the perception of shades

Two marked squares, if they lie in the same plane, look almost the same shade (Fig. A).

If the sheet is slightly curved, the illusion of a difference in shades is created (Fig. B).

If the squares lie in parallel planes, then the illusion of changing shade will decrease slightly (Fig. C), and increase if zones are designated (Fig. D).

By the way, here it should be noted a slight inaccuracy in the definition: in these illusions it is used grey colour, which is achromatic and has no shades.)) What is called “hue” in the description is actually tone (lightness). If you use any other color in the illusion, everything will be correct.

White squares

Here you can observe two illusions at once. The illusion of stripes moving relative to each other and deception of shade (gray-white squares have the same color and shade, but look different).

Knill and Kersten illusion

In Fig. 1, the squares appear identical. Let's move them together (Fig. 2) - it turns out they were different.

To enhance the effect, we transform the squares into cubes, maintaining the shade of the front side (Fig. 3).

And then, we transform the cubes into cylinders (Fig. 4), as you can see, the effect of “difference” has decreased.

Mysterious square

Let's do a simple experiment: the top picture shows a green square and four gradient stripes. Move the stripes to the center ( medium drawing). As the stripes approach the center, you will see dirt near their “imaginary” intersection.

Look at the bottom picture. The ring of mud around the cross became very obvious. Although in reality there is no dirt. The color around the cross is pure white. Thus, you see in the picture the illusion of image contrast.

Morrone-Burr-Ross illusion

In each rectangle right part(in the triangle) appears darker than the left one, although in fact the brightness is the same.

T-merge illusion

Gray vertical rectangles of the same color and shade.

Distortion of colors

In the top picture, areas 1 and 2 have the same background. Let's put circles with gradients on top of the picture, and as you can see in the two bottom pictures, areas 1 and 2 began to have a different shade.

In fact, areas 1 and 2 are the same color in all three pictures.

Squares

Square A is absolutely equal in color to square B, although due to the surroundings they seem completely different.

Snake

In Figure A, all the diamonds look different shades, although in fact they are the same shade. This is clearly visible if you remove part of the background that misleads you - see Fig. B.

Points

Two dots are exactly the same color and shade, but appear different because of the difference in background.

Another grid variation

Horizontal thin lines are colored evenly, although the illusion of a change in shade is created as vertical wide stripes of different tones intersect.

Block-Gafter effect

On the left are rhombuses, on the right they were combined into a large rhombus, but the colors did not change .

Optical illusions (visual illusions, optical illusion) - errors in visual perception caused by inaccuracy or inadequacy of unconscious correction processes visual image(lunar illusion, incorrect assessment of the length of segments, the size of angles or the color of the depicted object, illusions of movement, “illusion of the absence of an object” - banner blindness, etc.), as well as physical reasons (“oblate Moon”, “broken spoon” in a glass with water). Causes optical illusions investigated both when considering the physiology of vision and within the framework of studying the psychology of visual perception.

Illusions of color perception

It has been known for about a hundred years that when an image consisting of light and dark areas appears on the retina of the eye, light from the brightly lit areas seems to flow into the dark areas. This phenomenon is called optical irradiation. One of these illusions was described in 1995 by Edward Adelsen, a professor at the Machassuaset Institute of Technology ("Adelson's shadow illusion"). He noticed that the perception of color depends significantly on the background and the same colors on different backgrounds are perceived by us as different, even if they are close and visible to us at the same time.

(the third and fourth squares are the same color)

(at the intersection of the “petals” you can see pink dots. In fact, they are not there)

(rectangles “A” and “B” are the same color)

(if you look at the cross in the center of the field, then in the moving void after a while you can see green dot, which is actually not there)

(at the intersection of meridians and parallels you can see blinking black and white dots. in fact, they are ALL white)

(if you look at the fly on the right rectangle for 30 seconds, and then move your gaze to the left photo with a cow, it will acquire natural colors)

(horses on the left and right are the same color)

(at the intersection of the lines you can see blinking black and white dots. in fact, they are ALL white)

(at the intersection of meridians and parallels you can see blinking blue-white dots. in fact, they are ALL blue)

(at the intersection of the lines you can see flashing dots. In fact, they are not there)

(volume effect)

(upper and lower cubes are of the same saturation)

(dots on the faces of the cube of the same saturation)

(red stripes in the center of the top two squares and green stripes in the center of the bottom two squares of the same saturation)

(volume effect)

(the square in the center is not pink, but gray)

(the points on the left and right of the picture are the same shades)

(when continuously viewing the center of the picture, the bright spots will disappear after a while, and the square will completely turn gray. This is caused by retinal fatigue)

(an illusion very similar to the previous one. When continuously viewing the center of the picture, the gray haze around the point will disappear. Caused by retinal fatigue)

(when continuously viewing the center of the picture, the yellow dots will disappear after a while. Caused by retinal fatigue)

Illusion of color and contrast

Look at the center of the picture.
At the intersection of all the white stripes, small black circles are visible. At the same time, if you concentrate your gaze on any of these intersections, the circle disappears. The illusion is known as the Goering Grid.

Do you see a chessboard with white and black squares?
Gray halves of black and white cells of the same shade. Gray color is perceived either as black or as white.

Pay attention to the shades of the circles.
When surrounded by green, gray appears lilac-pink, and when surrounded by red, it appears blue-greenish.

How many colors were used to paint this picture?
Three: white, green and pink. The presence of different shades of green and red in the picture is just an illusion. Its occurrence depends on whether the green and pink squares are adjacent to each other, or whether there is also a white one between them.

Which circle is lighter?
Here the circles are exactly the same shade of gray. But when compared to the background saturation, they appear to be a lighter or darker shade.

Look at these two squares. Which square is brighter?
The color of the figures appears brighter and more saturated if the figures are edged with black frames. In fact, in both one and the other square the colors are exactly the same.

Fix your gaze in the center of the picture.
Goering grid. At the intersections of all white stripes, with the exception of the intersection where you are fixing your gaze at the moment, small gray spots are visible. As you can imagine, they don't actually exist.

Which half is more saturated in color?
The tone of the lower half seems more saturated, despite the absolute sameness of the colors of both halves. The illusion occurs due to the presence of a white outline at the top of the design.

Fine known to physicists and effect on doctors.
Mach bands. A smooth transition of color is perceived as stripes. At the border of white it is even more visible white stripe, and on the border of black - even blacker. The reason for this illusion is lateral inhibition in the retina, in other words, the peculiarities of the processes and structure of our eyes.

Look at the picture and pay attention to the red spots that appear at the intersection of the black lines.
The reason for this illusion is, among other things, the structural features of the retina.

Which part of the ring is darker?
Part of the ring appears darker against a white background. If you remove the pencil, the illusion disappears. Try this experiment with real paper and pencil.

Pay attention to the board.
It's hard to believe, but white cells in the shadow and black cells in the light are the same color. At the same time, our brain does not perceive this. Our perception, due to a centuries-old habit, makes allowances for the shadow that the timber supposedly creates, and automatically sends signals to the brain to “highlight” the squares in the shadow in our consciousness in order to compare them with the colors in the rest of the space.