Eyes full of illusions

Traveling the world to dazzle your eyes, you sometimes come across astonishing phenomena which, behind their veil of mystery, are clarified by rational explanations. Welcome to the land of effects and optical illusions.

Sylvain Sarrazin
The Press

The natural

A fiery waterfall

Yosemite National Park is full of natural wonders, with its granite giants popular with hikers and climbers. There is also a very special waterfall, Horsetail Fall, affected by a rare and captivating optical phenomenon. Throwing itself from the eastern face of Mount El Capitan, this modest flow of water becomes a real attraction in the second part of February, since it finds itself, in certain weather conditions, lit from behind by the setting sun. The effect is magical, giving an orange or golden tint to the fall, giving the impression that it is on fire. “This unique luminous phenomenon only occurs in the evening, with a clear sky and if the waterfall has formed. The slightest mist or cloud cover can mitigate or prevent it,” say park officials.

Fata Morgana, a mirage in the air

In the distance, mountains smoking, boats floating above the water, buildings chipped at their base… sometimes, the horizons show us all the colors and all the shapes. These mirages, known as Fata Morgana and once believed to have magical properties, are easily explained by optical theory, and the deflection of light as it passes through different temperature layers in the air.

“This results from the fact that the atmosphere does not have the same temperature everywhere, which changes the index of refraction in the air and deflects the light rays, indicates Simon Thibault. We look at objects in a straight line, but some light rays may be bent due to temperature change before returning to our eye. In fact, what we see is a copy of the mountain, sometimes deformed. It’s the same phenomenon of mirage when we have the impression of seeing water on the road when it’s hot, when it’s the light of the sky that is deviated towards our eye. »

Fata Morgana can be seen all over the world, from Bolivia to Lake Geneva, and it seems that Chaleur Bay would be a good observation post, when the weather conditions are right.

A fiery waterfall

Yosemite National Park is full of natural wonders, with its granite giants popular with hikers and climbers. There is also a very special waterfall, Horsetail Fall, affected by a rare and captivating optical phenomenon. Throwing itself from the eastern face of Mount El Capitan, this modest flow of water becomes a real attraction in the second part of February, since it finds itself, in certain weather conditions, lit from behind by the setting sun. The effect is magical, giving an orange or golden tint to the fall, giving the impression that it is on fire. “This unique luminous phenomenon only occurs in the evening, with a clear sky and if the waterfall has formed. The slightest mist or cloud cover can mitigate or prevent it,” say park officials.

A hanging lake

Anyone who goes to the top of the cliff Trælanípan, in the Faroe Islands, finds themselves in front of a strange optical illusion. Opposite the hiker is Lake Leitisvatn (also called Sørvágsvatn by some locals), which seems to be perched very high above sea level, visible below. But “the floating lake” is in fact only a few meters from the ocean, the eye being deceived by the arrangement of the surrounding cliffs, the perspective giving the impression that it is rather at hundreds of meters. upper. This is the largest body of water in the area, and it is possible to sail there by kayak, according to the local tourist office.

The road

Attractive magnetic ribs

Cars in neutral backing up a slope on their own, as if they were being sucked in or attracted by a magnet? This is the impression felt by drivers who have left to rub shoulders with the “magnetic coasts”, which can be found from Scotland to Australia via Moncton or Quebec (in Chartierville, in Estrie, in Buckland , in Chaudière-Appalaches). Here, no physical phenomenon strictly speaking, because it is an interpretation of our brain, deprived of landmarks (like the horizon line), which makes us think that we are going up, while we are going down.

“It’s a sham. When we don’t have reference points in space, it’s difficult to know if what we see is a perspective effect or a real effect. In the case of magnetic coasts, the whole environment prevents us from having fixed reference points, we are just deceived by the geometry. For example, if you follow a perfectly straight road and border it with ever smaller bushes, you might think that you are going down”, illustrates Mr. Thibault, who himself experienced a magnetic hill in his childhood; without much success!

A bridge to heaven

In western Norway, the route of Atlantarhavsvegen (“Atlantic Road”) jumps from islet to islet across elegant bridges, offering spectacular views of the ocean. If the sunsets and the maritime furies are famous there, a small comical thing also attracts the gaze of the curious: observed from a certain angle, the Storseisundet bridge seems to rise and lead to… nothing. From a distance, a driver has the impression of heading straight for a giant springboard that will plunge him into the Atlantic. In fact, it is the unusual curvature of the bridge that creates the illusion of a sharp stop in the roadway. A parking lot just before the structure allows you to admire the trompe-l’oeil at leisure. This 36 km route, some sections of which are bordered by the sea on both sides, can also be followed by bicycle.

3D pedestrian crossings

From India to Iceland via China and France, many countries have started to paint three-dimensional pedestrian crossings on the road, giving motorists the impression that they are heading straight for blocks placed on the floor. Here, there are no complex scientific secrets, just a question of perspective that does not fail to intrigue motorized visitors.

The artistic

Trompe-l’oeil in spades

Artists compete in imagination to disguise reality and sow doubt in our retinas. Trompe-l’œil and other installations designed to create illusions number in the thousands around the world. Close to us, some towns like to play tricks on their visitors, such as Quebec, where there are three mural works blending into the decor, including The fresco of Quebecers and that of Petit-Champlain, of a historical nature. Sherbrooke is not to be outdone, with 18 chameleon murals scattered along a circuit showcasing the city’s history and culture. We love Destinies and origins, which seems to open a wall on nature. In addition, a mobile application allows them to be brought to life. To discover !

A handkerchief in the sky

Among the countless existing works of art playing on optics, let’s mention this one, signed Neil Dawson and installed on the grounds of Gibbs Farm, a gigantic outdoor visual art exhibition venue. What, up close, looks like a rather conventional metal structure turns into a tissue paper landing on a hill when observed from a distance. You would swear it was drawn with a marker on the sky, taken from an animated film. Striking!

Alicia Martín’s book stunts

Strictly speaking, they are not optical illusions, but Alicia Martín’s works have not failed to catch the eye of tourists and Internet users around the world. About fifteen years ago, the woman from Madrid inaugurated a series of sculptures, Biographies, featuring 5000 real books assembled in such a way as to give the impression of springing from a window like a waterfall. First presented at the Casa de América in Madrid, the concept then toured the world, from The Hague to Mexico City. Unfortunately, she would not exhibit any at the present time.

Museums

Illusions are not only found in nature or on the street, they can also hide between four walls. No less than 34 international cities have a branch of the Museum of Illusions, including Toronto. Twenty additional branches are planned, including in Boston. Optical decoys, antigravity room, mirror games, holograms… a host of fun activities, calibrated for photography and filled with scientific explanations, set traps for the curious.