Which dress is black or. Is the dress blue or gold? What is the phenomenon? Purple Fighter: A more impressive demonstration of the Troxler effect. If you look steadily at the black cross, the motionless purple circles disappear, leaving only the moving green circle

Do you believe what you see? Especially for you - pictures that deceive the eyes and the brain.

What color is this dress?

This dress (by the way, what color is it?) blew up the Internet and in a matter of hours divided the world into two camps. For those who have spent the last few days in a coma, here's a quick rundown of what happened. The author of the photo posted it on Tumblr with the question “What color is this dress?” However, it was not possible to obtain a unanimous answer: some people see in this photo blue dress with black lace inserts, brightly illuminated by electric warm light, others claim that the dress is white, the inserts are golden, and the dress itself is in the shade.

The dress became a meme in no time and has already become endlessly boring to everyone. Ultimately, however, this illusion is just a demonstration of one of many ways to fool imperfect human vision. We've collected 16 more optical illusions that will make you not believe your eyes.

Shadow illusion on a chessboard: squares A and B are actually the same color!

"Neon" color spread: Neon lines make us think that the central area of ​​the picture is colored light blue. In fact, the background is the same white everywhere.

Troxler Effect: If you stare at a red dot without blinking long enough, the green circle will disappear.

White's illusion: the gray stripes under the letters A and B are actually the same color!

Apparent movement: Due to the contrast of colors and shapes, we think that the figures are moving, but the image is completely static.

Flickering grid: if you look at the picture, you will think that black dots appear and disappear at the intersections. In reality, all the dots are white.

Watercolor Illusion: The light colored lines on the inside of the figure make the orange appear to fade into white, but this is an illusion.

Tile illusion: The horizontal lines are straight and parallel to each other, but the human eye sees them as running at an angle.

Purple Fighter: A more impressive demonstration of the Troxler effect. If you look steadily at the black cross, the motionless purple circles disappear, leaving only the moving green circle.

Spinning Ballerina: Does the girl spin clockwise or counterclockwise? It depends on which leg your brain considers the fulcrum.

Zellner Illusion: In this picture, the long lines appear to be non-parallel because the short lines are at an angle to each other. However, in reality they are parallel.

For several days now, the whole world has been plunged into one big debate: what color is the dress - blue and black or white and gold?

It all started when Scottish singer Caitlin McNeil, under the nickname Swiked, posted a regular photo of a dress on Tumblr. In the caption, the girl explained that she and her friends couldn’t figure out what color it was:
- People, help! Is this dress white and gold or blue and black? My friends and I cannot agree on this. And it drives us crazy!

And within a matter of hours, millions of people were divided into two camps: some claimed that the outfit was blue and black (#blacknblue), while others said it was white and gold (#goldandwhite). The color of the dress even had its own hashtag #TheDress, which topped the top trends in the world.

But even after the girl confirmed that it was indeed blue with black stripes, the online debate did not stop.

Even the stars argued on Twitter:

Kim Kardashian:

What color is this dress? I see white and gold, but Kanye saw blue and black. So what color is it?!

Taylor Swift:

I don't understand this debate about the color of the dress. I'm scared already. PS: it's blue and black!

What do the “white and gold” (#goldandwhite) team think?

Looking at the photo, people who thought the dress was white and gold most likely paid attention to the background. Mistaking the bright backlight for sunlight, they decided that the dress was in the shade, which means that its light areas should change tone towards a bluish tint.
What does the “blue-black” (#blacknblue) team think?

“Blue-blacks,” on the contrary, look at the light areas of the dress out of context and clearly state that they are bluish or blue, while instead of “golden” fragments in the photo they see black ones, keeping in mind the effect when, due to the bright light under At a certain angle, black becomes rusty brown or even golden.

This creates an amazing construction in which one conflicting side defends its direct observations, and the other defends its forecasts.

Experts explain that such different perceptions are due to the structure of each person's eye, as well as the calibration of the monitor on which he looks at this dress, and the lighting of the room in which he is located. At the same time, experts unanimously say that such discrepancies in colors are extremely rare.

This is physics. In other words, in the case of a photograph, people mistake the light in the background for sunlight and conclude that the dress is in the shadow, which means that its light areas should turn bluish. So, there is no pure white, however, our brain comes up with the whiteness of the snow or the dress for us.

Others ignore the light in the background and see a blue dress. They call the gold fragments black because they remember that if you look at a black object in the bright sun, you can see gold.

Ophthalmologists explained the reason for what was happening in their own way:

Your retina is made up of “rods” and “cones” that convert light stimulation into nerve stimulation. They convert the signal differently. “Wands” are more sensitive to light, see shadows, and work more effectively in the dark. “Cones” are sensitive to color, but less sensitive to light. That is, in low light conditions, you see more with rods than with cones.

The dress appears blue/black or white/gold depending on whether your eye has more rods or cones and the lighting conditions in the room. (This is made possible by the different colors that mix around you.) Different people have different "rod" and "cone" remnants—those with color blindness are primarily affected.

But the "rods" are also very sensitive to light. The rods detect color using a pigment called rhodopsin, which is very sensitive to low light but flashes and is destroyed at higher light levels. And it should take about 45 minutes to adjust (well, just like your eyes will need time to adapt to the night, in other words). Basically, if you look at a dress in bright light and see one color, then if you go into a dark room for half an hour and come back, the dress will quite possibly change color.

Image caption Blue or white - that is the question

This dress split the internet in two. "Blue-black or white-gold?" – Kim Kardashian summed up the essence of the dispute on Twitter. How can we look at the same dress and see it so differently?

The answer to this question lies in the influence of sunlight on our color perception.

When we see something with our own eyes, we rarely have doubts about the authenticity of what we saw. Meanwhile, mistakes happen. If you think this dress is white and gold, you are absolutely wrong.

"What color is this dress? I see white and gold. Kanye – black and blue. Who is colorblind?" - Kardashian wrote on Twitter.

Commentators were quick to start arguing in the comments. Actress Julianne Moore sees white and gold, while singer Taylor Swift and singer Justin Bieber see blue and black.

Expert opinion

We asked BBC photo editor Emma Lynch to help figure it out.

After computer analysis of the image, she gave a clear answer: the dress is blue. By increasing the tone, but without adding other colors, it becomes obvious that the dress is blue and not white.

This conclusion is confirmed by using tools that show the color coding of each pixel. Various shades of blue are shown throughout.

How it all started

The same thing is said by the person who originally distributed the picture that caused so much controversy.

Kathleen McNeil plays in a folk ensemble that performed at a wedding in Scotland. The bride's mother bought the same dress for the wedding, showed the photo to the newlyweds, and an argument immediately broke out.

Kathleen McNeil confirms that the dress is made by Roman Originals. It is sold in several color options, but white and gold is not among them.

Why do we see color differently?

According to the computer technology site Wired.com, the disagreement can be explained by the way the human eye filters out the effects of daylight.

The same color may appear pink-red at dawn, blue-white during the day, and red at sunset. But the brain corrects for sunlight and can identify a different color as “real.”

That's why some people see a blue dress, but their brain thinks it's an optical illusion when in reality the dress is white. Others attribute Blue colour the dress itself.

This brain ability has evolved over thousands of years, but something about the photograph of the dress revealed individual differences in color perception.

Most likely, everyone remembers that very dress that set the entire Internet on edge. People heatedly discussed and argued about what color it was - white-gold or blue-black. Now researchers have decided to approach this issue from a scientific point of view.

What did scientists find out?

Research by scientists has led to conclusions that indicate that the difference in human perception of color largely depends on how the human brain generally perceives colors in daylight. It has long been known that the shapes and colors of an object can be viewed completely differently by two people. However, it was the dress that became one of the most dramatic and sensational examples. And now, through research into the colors in this dress, it has become clear that the answer to the famous question of whether all people see colors the same is not necessarily yes.

Color Constancy

In one study, scientists asked nearly 1,500 people to look at a photograph of a dress they had never seen before and say what color it was. Fifty-seven percent of those surveyed said it was blue-black, thirty percent said the color of the dress was white and gold, 11 percent described it as blue-brown, and 2 percent chose a different answer. Some subjects reported that they saw completely different colors when they looked at the photo a second time later. Differences in the perception of color occur because the brain makes an idea of ​​lighting, adjusting the colors so that the same object looks the same in any light. This property is known as color constancy. People who saw the white-gold color thought the dress was illuminated by bright daylight, so their brains ignored the shorter blue wavelengths. Those who saw the blue-black color assumed that the dress was illuminated by warm artificial light. Interestingly, older people were more likely to have seen the white and gold dress. The reason for this may be the fact that older people are more active during the day, while younger people begin their activity in the late afternoon.

Daylight vs artificial light

Another group of researchers had fifteen volunteers look at the dress, but it was displayed on a high-definition screen under controlled lighting and precise screen settings. Instead of seeing standard dress colors, subjects reported seeing a range of shades. Moreover, if the brightness of the light increased, they saw White dress, and if it decreased - blue. The researchers found that people most often reported seeing the same colors that can be found in daylight, which is typically bluish at midday and yellowish in the late afternoon. Thus, this phenomenon would not be possible if the dress were, for example, red. It was the blue and yellow (gold) colors that created such a hype around this dress; otherwise no one would have paid attention to it.

New color property

The third study was conducted on 87 college students who were also asked to report the color of their dress. About the same number of people said they saw blue-black and white-gold. The researchers then inverted the image so that the light stripes were pure gold and the dark stripes were pure blue. And in a follow-up study, 95 percent of participants reported seeing light yellow stripes. Thus, a new property of color was discovered, which concerns the perception of blue and yellow flowers. People are more likely to perceive a color as white or gray if the amount of blue in it changes. However, this is not as noticeable in other colors such as yellow, red or green.