It is said that seeing means believing. “Is it?” The illusions will ask. Should we trust everything we see?
For example, take this popular visual experiment ․ Do you think that one of the dark blue circles is bigger than the other? You are not the only one. But the reality is that they are absolutely equal.
The best visual illusions challenge our perception of reality. According to the famous neurologist, Dr. Bo Lotto ․ “The brain did not actually evolve to see the world as it is … The brain evolved to see the world as useful to see.”
Appearing Once in the Museum of Illusions will change your perception of how the reality around us is constructed.
We have gathered 6 illusions, which seem to challenge our brain.
- Troxler effect
Look at the center of this “blurry” image without blinking. What do you see in a few seconds? Did the image start to fade?
This visual phenomenon, called the Troxler Effect, was discovered in 1804 by the Swiss physician Ignaz Paul Vital Troxler. It reveals how our visual system adapts to sensory stimuli. Our neurons stop responding to constant stimuli, in this case the static blurred image of the background, causing the image to disappear from our consciousness.
- Pursuit of Purple
Look carefully at the center of the rotating purple circles for 20 seconds. You will start to see either a green dot that either rotates in a circle or a green circle. This deception is also known as the “pac-man” illusion. This is the result of our “negative retina” ․ That is, our visual perception tries to fill the gaps in space or the background in neutral color.
4 ․ Poggendorf deception (geometric)
Look at the picture on the left. Surely the black line is a continuation of the blue line, right? In fact, the line coincides with the red, as seen in the image on the right.
This illusion was named in honor of the German physicist Johann Pogendorf, who first described the phenomenon in 1860. Poggendorf’s illusion reveals how our brains perceive depths and geometric shapes, but the reason for this visual illusion is not yet properly explained.
5 ․ Shepard tables
Shepard’s tables are named after the cognitive scientist Roger Shepard, who published and explained this illusion back in 1990. It may seem that these two tables have completely different shapes: one is narrow and long, the other is short and wide. But, in fact, they are tables of the same size and shape, they are just moved so that one is horizontal and the other is more vertical.
The trick is related to the same perspective that underlies the photo of the railways ․ The train tracks seem to be almost vertical, but our brains know that they look like that only because they leave us.
Thus, we see not 2D lines, but 3D traces. Our brains interpret Shepard’s table in the same way. Seeing vertical lines, our brain perceives that it stretches in the distance, which means that the table on the left side looks much longer than it really is. The illusion, of course, dates back to the 1850s, when psychologist Adolf Fick noticed that people tend to think of vertical lines longer than horizontal ones. But what was hidden behind it was not explained until Shepard.
6 ․ Mirages
Most illusions arise because of neuroscience and psychology, but there are some that are related to the laws of physics. For example, mirages.
Mirages are caused by temperature fluctuations when a layer of warm air “meets” colder air on the ground.
A ray of light is refracted in air just like in water, but its degree of reflection depends on the temperature of the air. If the layer of hot air on the ground is quite thick and warm enough, it can have almost a mirror effect, reflecting the light falling on your eyes and creating a mirage. As the air is quite turbulent, the mirages give the impression that the light is reflected from the water. That is why when you hear that someone has seen water in the desert, you should not rejoice. In all probability, it was just a mirage.
Do not miss the opportunity to visit the Museum of Illusions to see more illusions in person, or even to touch them or to become an actor of deception.