Geometric Illusions

Pareidolia

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Pareidolia

Pareidolia is a psychological phenomenon in which the brain unconsciously perceives recognizable patterns or objects in random or ambiguous stimuli.

This can manifest in various ways, such as seeing faces in clouds, the moon, or other random shapes, hearing recognizable sounds in random noise, or interpreting random data as having meaningful significance.

Pareidolia is a type of apophenia, which is the tendency to see meaningful patterns in random or meaningless data. It is a natural part of human cognition and can serve as a survival mechanism, helping the brain to quickly identify potential threats in the environment.

However, pareidolia can also lead to misunderstandings and false perceptions. For example, some people might see religious imagery or messages in random patterns, leading to claims of miracles or supernatural phenomena. In other cases, pareidolia can lead to overinterpretation of scientific data or to conspiracy theories.

Overall, pareidolia is a fascinating aspect of human cognition and serves as an important reminder of the limitations of human perception and interpretation.

Pareidolia
Pareidolia


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How does Pareidolia work?

Pareidolia works by the brain unconsciously perceiving recognizable patterns or objects in random or ambiguous stimuli.

The brain is wired to recognize patterns and make sense of the world around us, and pareidolia is an example of how this process can sometimes lead to false perceptions.

Here’s how it works:

  1. Ambiguous stimuli: The brain is presented with stimuli that is unclear or open to interpretation, such as a random arrangement of shapes or a series of sounds that lack a clear pattern.
  2. Pattern recognition: The brain naturally seeks to identify patterns and make sense of the stimuli. In the case of pareidolia, it perceives recognizable patterns or objects in the ambiguous stimuli.
  3. False perception: The brain unconsciously creates a false perception of the stimuli, seeing a face in a cloud, for example, or hearing recognizable sounds in random noise.
  4. Confirmation bias: The brain tends to look for evidence to support its initial perception, leading to a confirmation bias that reinforces the false perception.

Overall, pareidolia works by the brain unconsciously perceiving recognizable patterns or objects in random or ambiguous stimuli, leading to the creation of a false perception.

While pareidolia can serve important functions, such as helping the brain to quickly identify potential threats in the environment, it can also lead to misunderstandings and false perceptions.


Versions of Pareidolia

The following are some alternate versions of Pareidolia:

Pareidolia


Pareidolia



Illusions like Pareidolia

Pareidolia is a type of perceptual illusion, specifically a form of apophenia. Apophenia is the tendency to see meaningful patterns or connections in random or meaningless data.

In the case of pareidolia, the brain unconsciously perceives recognizable patterns or objects in random or ambiguous stimuli, leading to the creation of a false perception.

For example, seeing faces in clouds, hearing recognizable sounds in random noise, or interpreting random data as having meaningful significance.

Pareidolia is a form of visual illusion in that it involves the misinterpretation of sensory information, leading to a false perception of patterns or objects in the environment.

It is also related to other types of illusions, such as optical illusions and auditory illusions, in that it involves the misperception of sensory information.

Some examples of illusions like Pareidolia include:

Illusory contours are visual stimuli that appear to form a boundary or shape, but in reality do not exist as a solid object.

Illusory contours are created by the brain’s interpretation of visual information, such as the arrangement and contrast of lines and shapes in the visual field.

The brain perceives these stimuli as a solid edge or contour, even though no physical boundary is present. Illusory contours are a well-known phenomenon in the field of visual perception, and are often used to study the brain’s interpretation of visual information.


Illusory Contour
Illusory Contours – Ehrenstein Figure


The Kanizsa triangle is a visual illusion that was first described by the Italian psychologist Gaetano Kanizsa in 1955. The illusion consists of a white equilateral triangle that appears to be surrounded by three Pac-Man-like shapes, which are black and have white crescents facing inwards.

The three Pac-Man-like shapes are actually made up of three partially-overlapping circles with white edges that create the illusion of a triangle.

Kanizsa Triangle Illusion
The Kanizsa Triangle

The Muller-Lyer illusion: an illusion in which two lines of the same length appear to be of different lengths due to the presence of arrowheads at the ends of the lines.


müller-lyer illusion



The Poggendorff illusion: an illusion in which two lines that are parallel in reality appear to be skewed or converging due to the presence of a third shape in the foreground.


Poggendorff illusion transparent gray bar



The Café Wall illusion: an illusion in which the lines that form a tiled wall appear to be skewed or distorted due to the presence of contrasting colored tiles.

Cafe Wall Illusion



The Zöllner illusion: an illusion in which parallel lines appear to be skewed or converging due to the presence of intersecting lines at an angle.

Zöllner illusion

The Ebbinghaus illusion: This illusion involves circles of different sizes, but with the same-sized circles placed close to each other. The brain perceives the smaller circles as being larger when they are placed next to larger circles.

Ebbinghaus Illusion


The T illusion: This illusion involves a T-shaped figure with a horizontal bar and a vertical bar. The brain perceives the vertical bar as being longer than the horizontal bar, even though they are the same length.


T Illusion


Moon illusion: This illusion involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.


Moon Illusion



Ponzo illusion: This illusion involves the perception of an object appearing larger or smaller depending on the size of the surrounding context.

Ponzo Illusion


All these illusions work by exploiting the way the brain processes visual information and the way it interprets the relationship between different elements in an image. Illusory contours are thought to be created by the activity of neurons that respond selectively to edges and contours in the visual field, which can be influenced by different visual cues.


Discovery of Pareidolia

The phenomenon of pareidolia has been known and documented by humans for centuries, but it wasn’t given a formal name or systematic study until modern times.

The term “pareidolia” was first used by psychologist Carl Jung in the early 20th century to describe the tendency to see meaningful patterns in random stimuli.

Since then, pareidolia has been the subject of research and study in the fields of psychology, neuroscience, and perception, with many scientists and researchers exploring the underlying mechanisms and implications of this phenomenon.

While it’s difficult to say who exactly “discovered” pareidolia, Carl Jung’s use of the term marked a major step forward in the systematic study and understanding of this fascinating aspect of human cognition.

Carl Jung was a Swiss psychologist and psychiatrist who was born in Kesswil, Switzerland in 1875. He is best known as the founder of analytical psychology, which is a school of psychology that emphasizes the role of the unconscious mind in shaping human behavior and experience.

Jung’s work was deeply influenced by his training in psychiatry and his interest in Eastern philosophy, spirituality, and mythology. He developed the concept of the collective unconscious, which is the idea that the unconscious mind is not just personal, but also collective, containing universal archetypes and symbols that are shared by all humans.

Jung’s ideas have had a significant impact on the field of psychology and on the larger culture, influencing fields such as literature, film, and art. He wrote many influential books and articles, including “Man and His Symbols,” “Memories, Dreams, Reflections,” and “The Interpretation of Dreams.”

Overall, Carl Jung was a highly influential figure in the field of psychology and is considered one of the founding figures of modern psychology. His ideas continue to shape our understanding of the human mind and human behavior to this day.


References and Resources

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Infinity Mirror

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Infinity mirror

An infinity mirror is a type of optical illusion created by reflecting a source of light repeatedly between two parallel mirrors, creating a seemingly infinite series of reflections that fade into the distance.

The effect is achieved by using one mirror that is partially transparent, allowing some of the light to pass through and escape from the series of reflections.

This creates the illusion of an infinite reflection, hence the name “infinity mirror.” Infinity mirrors are often used for artistic or decorative purposes and can add a mesmerizing effect to any space.


Infinity mirror
Infinity mirror


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How do Infinity Mirrors work?

An infinity mirror works by reflecting light between two parallel mirrors.

The first mirror is a regular mirror, while the second mirror is partially transparent, allowing some of the light to escape and pass through to the other side.

Here’s how it works in detail:

  1. A light source, such as an LED light, is placed at one end of the mirror setup.
  2. The light from the source is reflected by the first mirror, creating a reflection.
  3. This reflection is then reflected by the second mirror, and the process is repeated multiple times, creating a series of reflections that appear to fade into the distance.
  4. The partially transparent mirror allows some of the light to pass through, creating the illusion that the reflections are continuing into the distance.
  5. The final result is an optical illusion of an infinitely long series of reflections, hence the name “infinity mirror.”

This illusion can be created in a variety of shapes and sizes and can be used for artistic or decorative purposes.

The mesmerizing effect of an infinity mirror often captivates viewers and can add a unique touch to any room or space.

Versions of the Infinity Mirrors

The following are some alternate versions of the Infinity Mirrors:

Infinity mirror


Infinity mirror




Illusions like Infinity Mirrors

An infinity mirror is a type of optical illusion that creates a seemingly endless series of reflections.

It’s a perceptual illusion that tricks the mind into perceiving a much larger space than what is actually present.

The reflection of light between two mirrors is what creates the illusion, and the partially transparent mirror that allows some of the light to escape is what gives the illusion its depth and makes it appear as though the reflections go on forever.

This illusion is often used for artistic or decorative purposes and can create a fascinating and mesmerizing effect.

Some related illusions include the following:

Anamorphic street art is a form of street art that uses optical illusion to create a three-dimensional image when viewed from a specific angle.

Anamorphic street art is often created by distorting the image, so that when it is viewed from a specific viewpoint, the image appears to be three-dimensional and in full perspective.

It is often seen as a way of transforming urban spaces into playful, interactive environments.

Anamorphic street art
Anamorphic Street Art

The Penrose stairs, also known as the impossible staircase or the Penrose steps, is a visual illusion in the form of an impossible object created by the mathematician and physicist Roger Penrose.

The illusion is a two-dimensional representation of a staircase that appears to ascend or descend indefinitely, yet is physically impossible to climb or descend because the steps are not connected in a logical manner.

It is often used as an example of the type of optical illusion that can occur in the human brain and is used in cognitive psychology to study perception and attention.

Pensrose Staircase
The Penrose Staircase Illusion


The Penrose triangle, also known as the Penrose tribar, is an optical illusion that depicts a three-dimensional object that is physically impossible to construct.

Penrose Triangle

The Rubin vase, also known as the Rubin face or the figure-ground vase, is a famous optical illusion in which the image of a vase can also be perceived as two faces in profile looking at each other.

Rubin Vase Classic Black and White


The duck-rabbit illusion is an optical illusion that is an image that can be perceived as either a duck or a rabbit depending on how the viewer looks at it.

Duck Rabbit Illusion

The Necker cube is an optical illusion that features a simple wireframe drawing of a cube. The cube appears to switch back and forth between two different orientations.

Necker Cube

The My Wife and My Mother-in-Law illusion is an optical illusion with an image of a young woman’s face that can also be perceived as an older woman’s face.

Wife and Mother In Law

The Schröder Staircase is an optical illusion that features a drawing of a staircase. The staircase appears to be either ascending or descending, depending on how the brain interprets the angles of the lines.

Schroeders_stairs
From Wikimedia Commons

The impossible cube is an optical illusion that depicts a three-dimensional object that is physically impossible to construct.

Impossible Cube Illusion


The impossible trident is a three-pronged impossible shape resembling a trident. It is usually depicted as a three-pronged fork with each prong appearing to be a continuation of the next, creating an impossible shape.

Impossible Trident
From Wikimedia Commons

The spinning dancer illusion is a visual illusion that depicts a silhouette of a dancer spinning clockwise or counterclockwise. The direction of the dancer’s spin can appear to change depending on the viewer’s perception

Spinning Dancer Gif
From Wikimedia Commons

The impossible cylinder is an impossible shape resembling a cylinder similar to the Penrose triangle, impossible cube, and the impossible trident.

Impossible Cylinder

The Shepard elephant illusion is an optical illusion that was created by the artist David H. Shepard. The illusion is a black-and-white line drawing of an elephant that appears to be three-dimensional and in motion, despite being a flat, static image.

The illusion is created by using a technique called “anamorphosis,” which involves distorting an image in a specific way so that when it is viewed from a certain angle or perspective, it appears to be in a different form or shape.


Discovery of Infinity Mirrors

The concept of an infinity mirror is not necessarily the invention of a single person. The use of mirrors to create optical illusions and the idea of using partially reflective surfaces to create an illusion of depth have been around for centuries.

Yayoi Kusama is a Japanese artist helped popularize the infinity mirrow. She is known for her work in a variety of media, including painting, sculpture, installation art, performance art, and literary works. Born in 1929 in Matsumoto, Japan, Kusama has been a major figure in the international art world for many years and is widely recognized as one of the most important and influential artists of the 20th and 21st centuries.

Kusama is perhaps best known for her large-scale installations, many of which feature repetitive patterns and shapes that are intended to evoke a sense of infinite space. One of her signature forms of expression is the use of the infinity mirror, which she has used in a variety of ways throughout her career.

Her work is characterized by its vibrant colors, bold forms, and repetitive patterns, and she often creates immersive, multi-sensory installations that challenge conventional perceptions of space and time. Kusama’s work has been widely exhibited in museums and galleries around the world and has been the subject of numerous solo exhibitions and retrospectives. Today, she continues to work and create new works of art, and her influence on the art world is widely acknowledged.

References and Resources

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Penrose Figures

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Penrose Shapes

Penrose figures are impossible objects that were first described by the mathematician and philosopher Roger Penrose in the 1950s.

They are optical illusions that depict objects that appear to violate the laws of three-dimensional geometry. Penrose figures are typically drawn or represented as two-dimensional images, but they create the illusion of a three-dimensional object that cannot actually exist in the real world.

Some common examples of Penrose figures include the Penrose triangle, which appears to have vertices that join in impossible ways, and the Penrose stair, which appears to be a staircase that goes on forever, with the steps constantly descending and yet never reaching the bottom.

These figures challenge our perception of the world and have been used in art, architecture, and psychology to study the workings of the human mind and the limits of human perception.

Penrose Shapes
Penrose Shapes

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How do the Penrose Shapes work?

Penrose shapes work by exploiting the limitations of human perception.

They create the illusion of objects that violate the laws of three-dimensional geometry, by arranging two-dimensional lines and shapes in such a way as to suggest depth and perspective.

Our brains interpret these lines and shapes as representing a three-dimensional object, even though the object depicted is physically impossible.

The illusion arises because our brain relies on certain assumptions and expectations about the way objects should behave in space, and these assumptions are violated by the impossible objects depicted in Penrose figures.

As a result, our perception of the object is altered, and we see something that is not actually there.

The exact way that Penrose figures work is still not fully understood, and they continue to be a subject of study in the fields of psychology, neuroscience, and mathematics.

Penrose shapes have been used to study cognitive psychology and perception as it is a good example of how the human brain can be deceived by visual illusions, and also how we perceive and interpret visual information.

Versions of the Penrose Shapes

The following are some alternate versions of the Penrose Shapes:

Penrose Pentagram
Penrose Pentagram


Penrose torus
Penrose Torus




Penrose Pentabar
Penrose Pentabar

Penrose Trefoil
Penrose Trefoil

Penrose Angstrom
Penrose Angstrom



Illusions like Penrose Shapes

Penrose shapes are an optical illusion. They create the illusion of three-dimensional objects that appear to violate the laws of geometry, and as a result, our perception of the object is altered, and we see something that is not actually there.

Penrose shapes are a type of impossible object, which are objects that appear to be logically and physically impossible.

They are also a type of Paradox illusion. Paradox illusions are a type of optical illusion that involve images that appear to be self-contradictory or impossible. They typically involve the manipulation of visual cues such as size, shape, movement, and depth perception to create an image that appears to be impossible or defies our understanding of the physical world.

In general, these illusions work by exploiting the way the visual system processes information. The brain relies on certain cues, such as perspective, shading, and texture, to infer the 3D structure of an object. When these cues are manipulated in a certain way, the brain can be fooled into perceiving an impossible or self-contradictory image.

Some related illusions include the following:

The Penrose stairs, also known as the impossible staircase or the Penrose steps, is a visual illusion in the form of an impossible object created by the mathematician and physicist Roger Penrose.

The illusion is a two-dimensional representation of a staircase that appears to ascend or descend indefinitely, yet is physically impossible to climb or descend because the steps are not connected in a logical manner.

It is often used as an example of the type of optical illusion that can occur in the human brain and is used in cognitive psychology to study perception and attention.

Pensrose Staircase
The Penrose Staircase Illusion


The Penrose triangle, also known as the Penrose tribar, is an optical illusion that depicts a three-dimensional object that is physically impossible to construct.

Penrose Triangle

The Rubin vase, also known as the Rubin face or the figure-ground vase, is a famous optical illusion in which the image of a vase can also be perceived as two faces in profile looking at each other.

Rubin Vase Classic Black and White


The duck-rabbit illusion is an optical illusion that is an image that can be perceived as either a duck or a rabbit depending on how the viewer looks at it.

Duck Rabbit Illusion

The Necker cube is an optical illusion that features a simple wireframe drawing of a cube. The cube appears to switch back and forth between two different orientations.

Necker Cube

The My Wife and My Mother-in-Law illusion is an optical illusion with an image of a young woman’s face that can also be perceived as an older woman’s face.

Wife and Mother In Law

The Schröder Staircase is an optical illusion that features a drawing of a staircase. The staircase appears to be either ascending or descending, depending on how the brain interprets the angles of the lines.

Schroeders_stairs
From Wikimedia Commons

The impossible cube is an optical illusion that depicts a three-dimensional object that is physically impossible to construct.

Impossible Cube Illusion


The impossible trident is a three-pronged impossible shape resembling a trident. It is usually depicted as a three-pronged fork with each prong appearing to be a continuation of the next, creating an impossible shape.

Impossible Trident
From Wikimedia Commons

The spinning dancer illusion is a visual illusion that depicts a silhouette of a dancer spinning clockwise or counterclockwise. The direction of the dancer’s spin can appear to change depending on the viewer’s perception

Spinning Dancer Gif
From Wikimedia Commons

The impossible cylinder is an impossible shape resembling a cylinder similar to the Penrose triangle, impossible cube, and the impossible trident.

Impossible Cylinder

The Shepard elephant illusion is an optical illusion that was created by the artist David H. Shepard. The illusion is a black-and-white line drawing of an elephant that appears to be three-dimensional and in motion, despite being a flat, static image.

The illusion is created by using a technique called “anamorphosis,” which involves distorting an image in a specific way so that when it is viewed from a certain angle or perspective, it appears to be in a different form or shape.


Discovery of Penrose Shapes

Penrose shapes were first described by the British mathematician and philosopher Roger Penrose in the 1950s.

He published a paper on the topic in 1958, in which he introduced the concept of impossible objects and demonstrated how they could be used to create illusions that challenge our perception of the world. P

enrose’s work was inspired by the artist M.C. Escher, who was known for his use of impossible objects in his art, and Penrose sought to understand the mathematical and perceptual principles behind these illusions. His work laid the foundation for the field of impossible objects, and his name has become synonymous with the concept of impossible figures.

Today, Penrose shapes continue to be a subject of study in the fields of psychology, neuroscience, and mathematics, and they are widely recognized as one of the most famous examples of optical illusions.

One of the more famous Penrose shapes, the Penrose stairs, was first created by the British mathematician and physicist Roger Penrose and his father Lionel Penrose, a psychiatrist and mathematician, in the 1950s.

Sir Roger Penrose is a renowned British mathematical physicist and Nobel laureate. He was born in 1931 and is still active today. He is known for his work in the fields of cosmology, general relativity, and quantum mechanics. He was awarded the Nobel Prize in Physics in 2020, jointly with Reinhard Genzel and Andrea Ghez, for his contributions to the understanding of the properties of black holes.

Penrose’s research has focused on the fundamental nature of space and time and the structure of the universe, he proposed new ways of understanding the Big Bang, black holes, and the nature of the universe itself. He has also been interested in the connection between physics and mathematics, particularly in the area of geometry. Penrose has written several books on these topics, which have been widely read and discussed by both scientists and the general public.

Penrose is also known for his work on the concept of “cosmic censorship” which is a theory that states that the singularities that occur in black holes are always hidden from the outside observer. He also developed new mathematical techniques, such as the Penrose diagram, which are used to describe the behavior of black holes and other singularities. Penrose is considered one of the most influential theoretical physicist of the 20th century and his work has had a significant impact on our understanding of the universe.

References and Resources

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Illusion Knitting

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Illusion Knitting

Illusion knitting is a style of knitting where the pattern created appears to be different from the actual knit structure.

This is achieved by carefully choosing the colors and placement of stitches to create the illusion of a more complex pattern or image.

Illusion knitting often employs a technique called slip stitching, where certain stitches are slipped instead of being knit or purled, to create a hidden design that is revealed only when the knitting is stretched or viewed from a certain angle.

This style of knitting can be used to create a wide range of images and patterns, from simple geometric shapes to more complex designs featuring animals, landscapes, and portraits.

Illusion knitting is a fun and creative way for knitters to challenge their skills and create unique and eye-catching pieces.


Illusion Knitting
Illusion Knitting



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How does Illusion Knitting work?

Illusion knitting works by using the properties of light and color to create the appearance of a more complex pattern or image.

The technique employs slip stitching, where certain stitches are slipped instead of being knit or purled, to create a hidden design that is revealed only when the knitting is stretched or viewed from a certain angle.

By carefully choosing the colors and placement of stitches, the knitter can create the illusion of a pattern or image that is different from the actual knit structure.

The final product gives the impression of a two-dimensional image floating on the surface of the knit fabric, creating a visual trick that is both surprising and appealing. Illusion knitting requires careful attention to detail and a good understanding of color theory, as well as the ability to follow a pattern and execute the slip stitch technique accurately.

Versions of Illusion Knitting

The following are other examples of Illusion Knitting



Illusion Knitting



Illusion Knitting




Illusions like Illusion Knitting

Illusion knitting is a visual illusion. It creates the appearance of a more complex pattern or image than what is actually represented in the knit structure.

This is achieved by carefully choosing the colors and placement of stitches to create the illusion of a hidden design that is revealed only when the knitting is stretched or viewed from a certain angle.

The final product gives the impression of a two-dimensional image floating on the surface of the knit fabric, creating a visual trick that is both surprising and appealing.

Some related illusions include the following:

Anamorphic street art is a form of street art that uses optical illusion to create a three-dimensional image when viewed from a specific angle.

Anamorphic street art is often created by distorting the image, so that when it is viewed from a specific viewpoint, the image appears to be three-dimensional and in full perspective.

It is often seen as a way of transforming urban spaces into playful, interactive environments.

Anamorphic street art
Anamorphic Street Art


An autostereogram is a type of image that appears to be a flat 2D image when viewed normally, but when viewed with a special technique, it appears to be a 3D image with depth and perspective.

Autostereograms are created by repeating a pattern of repeating elements, such as random dots, in such a way that the repeating elements at different depths in the image align with each other when viewed with the special technique. This creates the illusion of a 3D image.

The image below appears as a 2 dimensional flat image, but when viewed using one of the techniques mentioned below, a 3 dimensional shape appears.



Phantograms are 3D images that appear to float in space and can be viewed without special glasses or other aids. The term “Phantogram” is derived from the Greek words “phaneros,” meaning “visible,” and “gramma,” meaning “something written or drawn.”

Phantograms are created by taking two photos of an object from slightly different angles and then printing the images on a flat surface, such as a piece of paper or card. The two images are then viewed together, and the slight differences in perspective create the illusion of depth and the appearance of a floating 3D object.



Persistence of vision is the phenomenon by which the brain continues to perceive an image even after the image is no longer present.

This occurs because the cells in the retina, called rods and cones, take a brief period of time to “reset” after being stimulated.





A color constancy illusion is a type of visual illusion in which a color appears to be different when viewed in different contexts.

For example, the same patch of color may appear lighter or darker when viewed against different backgrounds, or may appear to change color when viewed under different lighting conditions.


Color constancy
Color Constancy



The Checker Shadow Illusion is created by a checkerboard pattern composed of squares with different luminance values, the squares that are not directly illuminated by the light source appear darker than the illuminated squares, creating the illusion of shadows.



Edelson-Checker_shadow_illusion
Checker Shadow Illusion


The simultaneous contrast illusion is a visual effect that occurs when the perception of a color is affected by the colors of the surrounding area.

The illusion creates the appearance of a change in the color of an object, even though the actual color of the object remains constant.



Simultaneous Contrast Effect
The center green dot is the same on both sides, but the surrounding color changes the perception


The Neon Color Spreading illusion refers to the visual phenomenon where an area of color appears to spread or “bleed” beyond its intended boundaries.

Neon Color Spreading
From Wikimedia Commons



The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.  


Bezold_Effect
from Wikimedia Commons



The Cornsweet illusion is a classic example of a brightness illusion, which is an illusion in which two areas that are physically the same brightness appear to be different in brightness.

Cornsweet illusion
Cornsweet illusion


The Chubb illusion is based on the perception of brightness and can be observed when a small bright patch is surrounded by a larger dark area, the small bright patch will appear brighter than the same patch surrounded by a bright area.


Chubb Illusion


White’s illusion is a visual phenomenon in which two identical gray bars are placed on a background of alternating black and white stripes.

The gray bars appear to be different shades of gray, with the one on the white stripes appearing lighter than the one on the black stripes.

In the image below, both gray bars have the exact same color.


White's Illusion
White’s Illusion

The Watercolor Illusion: This illusion is created by the way the brain perceives edges of an object. When an object is surrounded by a colored halo, the object appears to have a different color than it actually does.

Watercolor Illusion



The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.


Cafe Wall Illusion


Discovery of Illusion Knitting

The origin of illusion knitting is unclear and it is difficult to determine who first discovered or popularized this technique.

However, the style has been around for many years and has been adopted by knitters all over the world. Illusion knitting has become increasingly popular in recent years, with many knitters exploring new and creative ways to use this technique to create unique and eye-catching pieces.

It is likely that the popularity of illusion knitting has been driven by the rise of social media, which has made it easier for knitters to share their work and connect with others who share their interests.

As a result, many different knitters and designers have likely contributed to the development and popularity of this technique including Tunisian Crochet


References and Resources

Check out our complete list of illusions and this other cool Illusion Knitting example.

Horsemaning

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Horsemaning

Horsemaning is a photography trick that creates an illusion of a person’s head being detached from the body and replaced by a horse’s head.

It’s achieved by aligning the head and body in such a way that it appears as though the head has been replaced. This trick became popular in the early 2000s and is now sometimes referred to as “headless horsemaning.”

Horsemaning
Horsemaning

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How does Horsemaning work?

Horsemaning works by aligning the person’s head and body in such a way that the head appears to be detached from the body.

This is typically done by taking a photo of a person from the waist up, with the head tilted forward, so that the head is obscured by the body.

Then, a second photo of a horse’s head is taken and carefully aligned with the first photo so that the horse’s head appears to be attached to the body.

The final image is created by merging the two photos together in a way that makes it appear as though the person’s head has been replaced by the horse’s head.

The effect is created by careful attention to detail, such as ensuring that the lighting and perspective match between the two photos, to create a seamless and convincing illusion.


Versions of the Horsemaning

The following are some examples of Horsemaning


Horsemaning



Horsemaning




Horsemaning



Illusions like Horsemaning

Horsemaning is a photographic illusion. It creates the illusion of a person’s head being detached from the body and replaced by a horse’s head.

This is achieved by careful alignment of the head and body in a photo to create the appearance of a horse’s head in place of the person’s head.

The final image gives the appearance of a detached head floating in the air, creating a surreal and amusing visual trick.

Some similar illusions are as follows:

Forced perspective is a technique used in photography, architecture, and other visual arts to manipulate the perception of the size and distance of objects.

It creates the illusion of a larger or smaller object, or of one that is closer or farther away, by carefully controlling the angles, proportions, and placement of objects in the scene.

Forced Perspective
Forced Perspective


The Ponzo illusion is a type of visual illusion in which a pair of parallel lines, or a horizontal bar, appear to be of different lengths based on the presence of a converging or diverging set of lines, often resembling the converging parallel lines of a road or railway track, placed above and below them.


Ponzo illusion
The Ponzo Illusion


The Ebbinghaus illusion: This illusion is similar to the Delboeuf illusion but in this case the central circle appears larger when surrounded by smaller circles and smaller when surrounded by larger circles.



Ebbinghaus Illusion

The Delboeuf illusion is a perceptual illusion in which the perceived size of a circle is affected by the size of the surrounding circles.





The Occlusion illusion is a visual illusion where an object that is partially obscured by another object appears to be farther away than it actually is. This illusion is caused by the brain’s interpretation of the relative depth of the objects based on their relative size and position. This phenomenon is based on the visual cues that the brain uses to perceive depth, such as relative size, position, and overlap.

The occlusion illusion

The Müller-Lyer illusion is a classic example of size-contrast illusion, in which two lines of equal length appear to be different due to the presence of arrowheads or fins at the end of the lines.

müller-lyer illusion


The moon illusions involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.

The Kanizsa triangle is a visual illusion that was first described by the Italian psychologist Gaetano Kanizsa in 1955. The illusion consists of a white equilateral triangle that appears to be surrounded by three Pac-Man-like shapes, which are black and have white crescents facing inwards.


All these illusions demonstrate that the perceived size of an object can be influenced by the context in which it is presented, and that the brain uses the size of the surrounding objects as a reference point to judge the size of the central object.

Discovery of Horsemaning

The origins of horsemaning are unclear, and it is difficult to determine who first started the trend.

This photographic trick has been around since the early 2000s, and became popular on social media platforms such as Facebook and MySpace.

Since then, it has been adopted by photographers and people all over the world as a fun way to create creative and surreal photos.

It’s likely that many people independently discovered this trick and started experimenting with it, so it’s impossible to credit a single person or group with starting the trend.

References and Resources

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Beuchet Chair Illusion

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Beuchet Chair Illusion

The Beuchet Chair Illusion is an optical illusion that involves a drawing or a photograph of a chair that appears to change shape and orientation as the viewer’s perspective changes.

In the Beuchet Chair Illusion, the chair is drawn or photographed from an oblique angle, causing it to appear distorted and impossible to sit in.

However, when viewed from a different angle, the chair appears to change shape and orientation, becoming a comfortable, normal chair that can be sat in.

This illusion demonstrates the importance of perspective in our perception of the world and highlights the role of context in shaping our perceptions.

Beuchet Chair Illusion
Beuchet Chair Illusion


Table of Contents

How does the Beuchet Chair Illusion work?

The Beuchet Chair Illusion works by taking advantage of the way our brain processes visual information. When we look at an object, our brain takes into account our perspective and any other surrounding information to form a three-dimensional representation of the object.

In the case of the Beuchet Chair Illusion, the chair is drawn or photographed from an oblique angle, causing the brain to perceive it as a distorted, impossible to sit in chair.

However, when the viewer changes their perspective or moves around the chair, the brain takes into account the new information and updates its representation of the chair.

This results in the appearance of the chair changing shape and orientation, becoming a comfortable, normal chair that can be sat in.

The Beuchet Chair Illusion shows that our perception of the world is not solely determined by the visual information that is in front of us, but is also influenced by our own experiences, expectations, and context.

Versions of the Beuchet Chair Illusion

The following are some other versions of the Beuchet Chair Illusion:


Beuchet Chair Illusion


Beuchet Chair Illusion





Illusions like the Beuchet Chair Illusion

The Beuchet Chair Illusion is an optical illusion that falls into the category of perspective illusions. Perspective illusions are optical illusions that involve the manipulation of perspective and the changing of the apparent shape, size, or orientation of an object as the viewer’s perspective changes.

The Beuchet Chair Illusion is an example of a perspective illusion because it creates the appearance of a chair changing shape and orientation as the viewer’s perspective changes. This illusion demonstrates the influence of perspective on our perception of the world and highlights the role of context in shaping our perceptions.

Some similar illusions are as follows:

The Leaning Tower Illusion is an optical illusion that involves the perception of the tilt angle of a tower or building.

In this illusion, although the images are duplicates, one has the impression that the tower on the right leans more, as if photographed from a different angle.



Forced perspective is a technique used in photography, architecture, and other visual arts to manipulate the perception of the size and distance of objects.

It creates the illusion of a larger or smaller object, or of one that is closer or farther away, by carefully controlling the angles, proportions, and placement of objects in the scene.



The Ponzo illusion is a type of visual illusion in which a pair of parallel lines, or a horizontal bar, appear to be of different lengths based on the presence of a converging or diverging set of lines, often resembling the converging parallel lines of a road or railway track, placed above and below them.


Ponzo illusion
The Ponzo Illusion


The Ebbinghaus illusion: This illusion is similar to the Delboeuf illusion but in this case the central circle appears larger when surrounded by smaller circles and smaller when surrounded by larger circles.



Ebbinghaus Illusion


The Delboeuf illusion is a perceptual illusion in which the perceived size of a circle is affected by the size of the surrounding circles.


The Occlusion illusion is a visual illusion where an object that is partially obscured by another object appears to be farther away than it actually is. This illusion is caused by the brain’s interpretation of the relative depth of the objects based on their relative size and position. This phenomenon is based on the visual cues that the brain uses to perceive depth, such as relative size, position, and overlap.


The occlusion illusion


The Müller-Lyer illusion is a classic example of size-contrast illusion, in which two lines of equal length appear to be different due to the presence of arrowheads or fins at the end of the lines.

müller-lyer illusion

The moon illusions involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.



The Kanizsa triangle is a visual illusion that was first described by the Italian psychologist Gaetano Kanizsa in 1955. The illusion consists of a white equilateral triangle that appears to be surrounded by three Pac-Man-like shapes, which are black and have white crescents facing inwards.



The Shepard table illusion is a type of perceptual illusion that is created by a table-like structure that appears to change its shape depending on the viewing angle.

The table is designed to have sides that are slanted, which creates an ambiguity in the visual perception of the object and makes it appear to change shape from a square to a rectangle or vice versa as the viewpoint changes.

The Shepard table illusion is a classic example of how the brain uses perceptual cues to form a coherent interpretation of the world and highlights the importance of context in shaping our perception.


Shepard Tables
Shepard Tables


All these illusions demonstrate that the perceived size of an object can be influenced by the context in which it is presented, and that the brain uses the size of the surrounding objects as a reference point to judge the size of the central object.


Discovery of the Beuchet Chair Illusion

The illusion is named after French psychologist Jules Beuchet, who first described it in the late 19th century.

The Beuchet Chair Illusion was first described by French psychologist Jules Beuchet in the late 19th century. Beuchet was interested in the way our brain processes visual information and the influence of context on our perception of the world. He created the Beuchet Chair Illusion as a tool to demonstrate these principles and to highlight the importance of perspective in our perception of the world.

Since Beuchet’s original description of the illusion, it has been widely used by psychologists and researchers as a tool for studying perception and the brain, and has become one of the most well-known and well-studied optical illusions.

Jules Beuchet was a French psychologist and physician who lived in the late 19th century. He is best known for his research in the field of psychology and his description of the Beuchet Chair Illusion.

Beuchet was interested in the way our brain processes visual information and the influence of context on our perception of the world. He made several contributions to the field of psychology and is remembered for his innovative research in the areas of perception and visual illusions.


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Anorthoscope

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Anorthoscope

An anorthoscope is a type of optical device used for viewing anamorphic images, which are distorted images that appear normal when viewed through a special lens.

An anorthoscope turns a distorted picture picture on a disc into a normal image through fast rotation behind a counter-rotating disk with slits.

The anorthoscope corrects the distortion of anamorphic images and allows the observer to see them in their proper, undistorted form.


Anorthoscope
Anorthoscope


Table of Contents

How does an Anorthoscope work?

An anorthoscope works by using a special lens to correct the distortion of anamorphic images. The lens, typically cylindrical in shape, compensates for the stretching or compression of the image that occurs when it is recorded in anamorphic format.

When viewed through the lens, the distorted image is transformed into its proper, undistorted form. This allows the observer to see the image as it was intended to be seen, without the distortion that was present in the original recording.

The anorthoscope is considered to be a predecessor of the phenakistiscope.

The phenakistiscope was one of the earliest animation devices and was invented in the mid-19th century. It used an optical illusion to create the appearance of motion from a series of static images.

The phenakistiscope used the same basic principle as the anorthoscope, in that it used a cylindrical lens to correct the distortion of anamorphic images, but it was specifically designed for the purpose of animation.

The phenakistiscope paved the way for later animation devices, such as the zoetrope and the praxinoscope, which would eventually lead to the development of motion pictures.

Versions of a Anorthoscope

The following are a few an alternates versions of the Phenakistiscope. The anorthoscope is considered to be a predecessor of the phenakistiscope.


phenakistiscope



phenakistiscope



phenakistiscope



phenakistiscope




Illusions like the Anorthoscope

The Anorthoscope is a mechanical optical illusion. It creates the illusion of motion by rapidly displaying a sequence of still images in quick succession, exploiting the persistence of vision phenomenon.

The Anorthoscope is considered one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today.

By creating the illusion of motion through the rapid display of still images, the Anorthoscope demonstrates how the brain processes visual information and creates the perception of motion.

The Anorthoscope works by exploiting the persistence of vision, which is the phenomenon where the brain continues to perceive an image for a short period of time after it has been removed from view.

Persistence of vision is a phenomenon where the brain continues to perceive an image for a short period of time after it has been removed from view. This is due to the fact that the neurons in the visual system take a brief amount of time to process an image before they reset. As a result, if an image is presented rapidly enough, the brain will perceive a continuous image even though the individual images are no longer present.

For example, when watching a movie or animation, the individual frames are presented in rapid succession, creating the illusion of continuous motion. This is because the brain perceives the brief interval between each frame as a single, continuous image.

The persistence of vision phenomenon is important in many areas of visual perception, including motion perception, the perception of images in sequence, and the experience of visual illusions such as the Zoetrope.

Understanding the persistence of vision is essential for explaining the way that our visual system processes information and shapes our perception of the world around us.

Some related illusions include the following:

The phenakistiscope is a mechanical optical illusion device that creates the illusion of motion by rapidly displaying a sequence of still images in quick succession.

It consists of a disk with slits around the circumference and a series of still images placed on the disk. When the disk is rotated in front of a mirror, the still images are reflected through the slits and appear to animate and move.

The phenakistiscope was invented in the early 19th century and was one of the earliest forms of animation. It was a precursor to motion picture technology and helped to lay the foundation for the development of cinema as we know it today.

The phenakistiscope is considered a historical artifact and is often featured in museums and exhibitions showcasing the history of animation and visual effects.


phenakistiscope
Phenakistiscope

A Thaumatrope is a simple optical toy that was popular in the 19th century.

It consists of a disk with a picture or design on each side that is attached to two strings. When the strings are spun rapidly, the two pictures appear to merge into a single, continuous image.


Thaumatrope GIF


The Stepping Feet Illusion is a visual illusion that involves an optical illusion of the apparent movement of a static image.



The kinetic depth effect refers to the perception of three-dimensional (3D) depth and solidity in an object that is produced by its motion, relative to the observer.



The spinning dancer illusion is a visual illusion that depicts a silhouette of a dancer spinning clockwise or counterclockwise. The direction of the dancer’s spin can appear to change depending on the viewer’s perception.


The beta movement illusion is a visual illusion in which a series of static images, such as a filmstrip or flipbook, appears to be in motion when viewed in rapid succession.



In Peripheral Drift illusions, the image or pattern appears to move or drift, even though it is actually stationary. This movement is caused by the brain’s attempt to interpret the image or pattern, which is often complex or ambiguous. The movement can be in any direction, such as horizontally, vertically, or diagonally.



Peripheral drift illusion jelly bean
From Wikimedia Commons


The rotating snakes is a peripheral drift illusion that consists of a grid of shapes, with some of them appearing to be rotating or undulating. The illusion is created by the interaction of the shapes with the neural processing of the visual system.


Rotating Snakes Autokinetic effect
A Version of Rotating Snakes


With Illusory motion, static image appears to be moving due to the interaction of color contrasts, shapes, and position



Troxler’s fading, also known as Troxler’s effect, is a phenomenon in which a stationary visual stimulus eventually disappears from perception, even though it is still present in the visual field.



Lilac-Chaser_Troxlers Fading


The stroboscopic effect is a visual phenomenon that occurs when a rapidly flashing light is used to illuminate a moving object.

The object appears to be frozen in a single position, even though it is in motion. This is because the flashing light is only on for a brief period of time, and the object is only visible when the light is on.

Stroboscopic effect


The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.



Simultaneous Contrast Illusion


The Motion Aftereffect (also known as the Waterfall Illusion) is a visual illusion experienced after viewing a moving visual stimulus, and then fixating on a stationary stimulus. The stationary stimulus appears to move in the opposite direction to the original stimulus.

For example, fixate on the moving image below for several seconds, then shift you gaze to another surface like a plain wall. You should still be able to see the motion on the static surface.


Motion-Aftereffect



The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.


Cafe Wall Illusion



Discovery of the Anorthoscope

The Anorthoscope was invented in 1829 by Joseph Plateau.

Plateau was a physicist who became interested in the study of optics and the way the human brain processes visual information. He discovered the persistence of vision phenomenon and began experimenting with mechanical devices that could exploit this phenomenon to create the illusion of motion.

Plateau’s invention of the phenakistiscope was one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today.

Joseph Plateau was a Belgian physicist and professor who lived in the 19th century. He is best known for his contributions to the study of optics and for inventing the phenakistiscope, a mechanical optical illusion device that creates the illusion of motion by rapidly displaying a sequence of still images in quick succession. Plateau’s invention of the phenakistiscope was one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today.

Plateau’s scientific work focused on the study of the human visual system and the way the brain processes visual information. He was one of the first scientists to discover the persistence of vision phenomenon and he used this discovery to develop the phenakistiscope. Plateau’s work has been recognized as an important contribution to the field of optics and the study of vision, and his invention of the phenakistiscope is considered a significant milestone in the history of animation and motion picture technology. Despite his many contributions to the field, Plateau is not as well-known as some of his contemporaries, such as Eadweard Muybridge, who made important contributions to the study of motion.

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Anamorphosis

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Anamorphosis

Anamorphosis is a technique in art and optics that involves creating an image that appears distorted or irregular when viewed from one perspective, but appears normal or regular when viewed from another perspective or with the use of a specialized tool, such as a mirror or a cylindrical lens.

Anamorphosis
Anamorphosis

Table of Contents

How does Anamorphosis work?

In anamorphic art, the image is typically drawn or painted in such a way that it is only recognizable when viewed from a specific angle or with the use of a specialized tool. The technique was widely used in the Renaissance period, particularly in the field of cartography, to represent three-dimensional objects on two-dimensional surfaces.

Anamorphosis can also be used to create optical illusions, where the distorted image appears to change or move when viewed from different angles. The technique is used in various fields, including art, architecture, and engineering, and provides a way to create images that are impossible to represent using conventional perspective techniques.

Overall, anamorphosis is a fascinating and versatile technique that demonstrates the interplay between art and science, and highlights the importance of perception and the role that context and perspective play in shaping our interpretation of the world.

Anamorphosis works by creating an image that is distorted or irregular when viewed from one perspective, but appears normal or regular when viewed from another perspective or with the use of a specialized tool, such as a mirror or a cylindrical lens.

The basic idea behind anamorphosis is to manipulate the scale of the image elements along one or more dimensions in such a way that the image appears distorted or irregular when viewed from a particular perspective. To create an anamorphic image, the artist must carefully adjust the position and size of the image elements to account for the distortion that will be introduced by the viewing angle or tool.

For example, an anamorphic image may be created by projecting an image onto a flat surface at an angle, such that the image appears distorted when viewed directly from the front. When viewed from a specific angle or with the use of a specialized tool, such as a cylindrical mirror, the image appears normal or regular.

Famous Anamorphosis Artists

Anamorphosis is a fascinating and versatile technique that demonstrates the interplay between art and science, and highlights the importance of perception and the role that context and perspective play in shaping our interpretation of the world.

Anamorphosis has been used by various artists throughout history, including some of the most famous and influential artists of their time. Here are a few notable artists who have used anamorphosis in their work:

  1. Leonardo da Vinci: Da Vinci was one of the earliest artists to experiment with anamorphosis and is widely regarded as one of the pioneers of the technique. He used anamorphosis in his sketches and drawings to represent three-dimensional objects on two-dimensional surfaces.
  2. Hans Holbein the Younger: Holbein was a German artist who lived in the 16th century and was known for his portraits, paintings, and drawings. He used anamorphosis in his portraits to create striking and unusual effects, and many of his anamorphic paintings are still regarded as some of the finest examples of the technique.
  3. René Magritte: Magritte was a Belgian surrealist artist who was known for his paintings, illustrations, and collages. He used anamorphosis in his paintings to create illusions and to challenge the viewer’s perception of reality.
  4. M. C. Escher: Escher was a Dutch graphic artist who is widely regarded as one of the greatest artists of the 20th century. He used anamorphosis in his prints, lithographs, and drawings to create impossible objects and to challenge the viewer’s perception of space and time.

These are just a few of the many artists who have used anamorphosis in their work, and there are many other artists who have also explored this fascinating technique. Overall, anamorphosis is a powerful tool for artists to create striking and unusual effects, to challenge the viewer’s perception, and to demonstrate the interplay between art and science.

Versions of Anamorphosis

The following are some examples of Anamorphosis


Anamorphosis



Anamorphosis




Anamorphosis



Illusions like Anamorphosis

Some similar illusions are as follows:

Trompe-l’œil is a French term that means “trick the eye.”

It refers to a style of art that uses realistic depictions of three-dimensional objects to create the illusion of depth and a life-like appearance.

Trompe-l’œil paintings and murals are often used to create the illusion of an extended space or to make a room appear larger than it actually is.

Trompe-l'œil Capri
Trompe-L’œil


Forced perspective is a technique used in photography, architecture, and other visual arts to manipulate the perception of the size and distance of objects.

It creates the illusion of a larger or smaller object, or of one that is closer or farther away, by carefully controlling the angles, proportions, and placement of objects in the scene.

Forced Perspective
Forced Perspective


The Ponzo illusion is a type of visual illusion in which a pair of parallel lines, or a horizontal bar, appear to be of different lengths based on the presence of a converging or diverging set of lines, often resembling the converging parallel lines of a road or railway track, placed above and below them.


Ponzo illusion
The Ponzo Illusion


The Ebbinghaus illusion: This illusion is similar to the Delboeuf illusion but in this case the central circle appears larger when surrounded by smaller circles and smaller when surrounded by larger circles.


Ebbinghaus Illusion

The Delboeuf illusion is a perceptual illusion in which the perceived size of a circle is affected by the size of the surrounding circles.



The Occlusion illusion is a visual illusion where an object that is partially obscured by another object appears to be farther away than it actually is. This illusion is caused by the brain’s interpretation of the relative depth of the objects based on their relative size and position. This phenomenon is based on the visual cues that the brain uses to perceive depth, such as relative size, position, and overlap.

The occlusion illusion

The Müller-Lyer illusion is a classic example of size-contrast illusion, in which two lines of equal length appear to be different due to the presence of arrowheads or fins at the end of the lines.

müller-lyer illusion

The moon illusions involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.

The Kanizsa triangle is a visual illusion that was first described by the Italian psychologist Gaetano Kanizsa in 1955. The illusion consists of a white equilateral triangle that appears to be surrounded by three Pac-Man-like shapes, which are black and have white crescents facing inwards.


All these illusions demonstrate that the perceived size of an object can be influenced by the context in which it is presented, and that the brain uses the size of the surrounding objects as a reference point to judge the size of the central object.


Discovery of Anamorphosis

The concept of anamorphosis has a long history and has been used by artists and scientists for many centuries. It is not clear who specifically discovered the technique, as it likely evolved over time and was developed independently by different artists and scientists in various cultures.

However, the Renaissance period marked a major period of experimentation and development in the use of anamorphosis in art and optics, and many of the most famous artists of the time, such as Leonardo da Vinci and Hans Holbein the Younger, made important contributions to the development of the technique.

Overall, it is difficult to credit the discovery of anamorphosis to a single individual, as it is likely a result of the collective work and experimentation of many artists and scientists over a long period of time.

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Shepard Tables

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Shepard Tables

The Shepard table illusion is a type of perceptual illusion that is created by a table-like structure that appears to change its shape depending on the viewing angle.

The table is designed to have sides that are slanted, which creates an ambiguity in the visual perception of the object and makes it appear to change shape from a square to a rectangle or vice versa as the viewpoint changes.

The Shepard table illusion is a classic example of how the brain uses perceptual cues to form a coherent interpretation of the world and highlights the importance of context in shaping our perception.

Shepard Tables
Shepard Tables

Table of Contents

How does the Shepard Tables Illusion work?

The Shepard table illusion works by exploiting the way our visual system processes depth and perspective. When we look at an object, our brain uses various cues, such as the size, position, and orientation of objects, to perceive its shape and position in three-dimensional space. In the Shepard table illusion, the slanted sides of the table create conflicting cues that lead to a perceptual ambiguity and an illusion of shape change.

One possible explanation of the illusion is that our visual system assumes that parallel lines recede into the distance, forming a trapezoidal shape that is wider at the bottom than at the top. In the Shepard table, the sides are slanted such that the top edge appears to be closer to the viewer, while the bottom edge appears to be further away. This creates a conflict between the perceived shape and the expected shape of the table, leading to an illusion of shape change.

Overall, the Shepard table illusion demonstrates the importance of context and the role of expectations in shaping our perception. It shows how our brain uses the information it has about the world to make predictions about what it is likely to see, and how these predictions can influence our perception of objects.

Versions of the Shepard Tables Illusion

The following are some other versions of the Shepard Tables Illusion:


Shepard Tables

Shepard Tables





Illusions like the Shepard Tables Illusion

The Shepard table illusion is a type of geometrical-optical illusion.

This type of illusion is characterized by the manipulation of basic geometric shapes, such as lines and shapes, to create a perceptual discrepancy between what is physically present and what is perceived.

Geometrical-optical illusions play with our visual system’s ability to perceive depth, size, and shape and often involve conflicting cues or assumptions about the world that our brain makes based on past experience.

Some similar illusions are as follows:

The Leaning Tower Illusion is an optical illusion that involves the perception of the tilt angle of a tower or building.

In this illusion, although the images are duplicates, one has the impression that the tower on the right leans more, as if photographed from a different angle.


Forced perspective is a technique used in photography, architecture, and other visual arts to manipulate the perception of the size and distance of objects.

It creates the illusion of a larger or smaller object, or of one that is closer or farther away, by carefully controlling the angles, proportions, and placement of objects in the scene.

The Ponzo illusion is a type of visual illusion in which a pair of parallel lines, or a horizontal bar, appear to be of different lengths based on the presence of a converging or diverging set of lines, often resembling the converging parallel lines of a road or railway track, placed above and below them.


Ponzo illusion
The Ponzo Illusion


The Ebbinghaus illusion: This illusion is similar to the Delboeuf illusion but in this case the central circle appears larger when surrounded by smaller circles and smaller when surrounded by larger circles.



Ebbinghaus Illusion

The Delboeuf illusion is a perceptual illusion in which the perceived size of a circle is affected by the size of the surrounding circles.


The Occlusion illusion is a visual illusion where an object that is partially obscured by another object appears to be farther away than it actually is. This illusion is caused by the brain’s interpretation of the relative depth of the objects based on their relative size and position. This phenomenon is based on the visual cues that the brain uses to perceive depth, such as relative size, position, and overlap.

The occlusion illusion

The Müller-Lyer illusion is a classic example of size-contrast illusion, in which two lines of equal length appear to be different due to the presence of arrowheads or fins at the end of the lines.

müller-lyer illusion

The moon illusions involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.

The Kanizsa triangle is a visual illusion that was first described by the Italian psychologist Gaetano Kanizsa in 1955. The illusion consists of a white equilateral triangle that appears to be surrounded by three Pac-Man-like shapes, which are black and have white crescents facing inwards.

All these illusions demonstrate that the perceived size of an object can be influenced by the context in which it is presented, and that the brain uses the size of the surrounding objects as a reference point to judge the size of the central object.

Discovery of the Shepard Tables Illusion

This illusion was first described by Roger Shepard and demonstrates how our perception can be influenced by the context in which an object is presented.

Shepard was a pioneer in the field of cognitive science and made important contributions to our understanding of visual perception, mental representation, and spatial cognition. The Shepard table illusion is one of many perceptual illusions that Shepard described and studied over the course of his career, and it remains an important demonstration of the role of context and expectations in shaping our perception of the world.

Roger Shepard was an American psychologist and cognitive scientist. He was born in 1929 and passed away in 2016.

He was a professor of psychology at Stanford University for many years and was one of the pioneers in the field of cognitive science. Shepard made important contributions to our understanding of human cognition, including visual perception, mental representation, and spatial cognition.

He was best known for his work on the structure of mental representations and the way in which they can be transformed and manipulated. Shepard was particularly interested in how our brain uses mental transformations to process information about the world and was a leading researcher in the field of cognitive psychology.

He received many awards and honors for his work and was widely recognized as one of the most influential psychologists of his generation.

References and Resources

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Phenakistiscope

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phenakistiscope

The phenakistiscope is a mechanical optical illusion device that creates the illusion of motion by rapidly displaying a sequence of still images in quick succession.

It consists of a disk with slits around the circumference and a series of still images placed on the disk. When the disk is rotated in front of a mirror, the still images are reflected through the slits and appear to animate and move.

The phenakistiscope was invented in the early 19th century and was one of the earliest forms of animation. It was a precursor to motion picture technology and helped to lay the foundation for the development of cinema as we know it today.

The phenakistiscope is considered a historical artifact and is often featured in museums and exhibitions showcasing the history of animation and visual effects.


phenakistiscope
Phenakistiscope


Table of Contents

How does a Phenakistiscope work?

The phenakistiscope works by exploiting the persistence of vision, which is the phenomenon where the brain continues to see an image for a brief moment even after it has disappeared. When the phenakistiscope disk is rotated in front of a mirror, the still images on the disk are reflected through the slits and appear to animate and move.

Here’s a step-by-step explanation of how the phenakistiscope works:

  1. A series of still images is placed on the disk of the phenakistiscope.
  2. The disk is rotated in front of a mirror, so the still images are reflected through the slits in quick succession.
  3. As the viewer looks at the reflection of the still images in the mirror, the brain combines the individual still images into a single, seamless moving image, creating the illusion of motion.

The speed at which the disk is rotated and the frequency at which the still images are reflected through the slits are crucial to the success of the illusion. If the rotation is too slow or the still images are not reflected frequently enough, the illusion of motion will not be created.

Versions of a Phenakistiscope

The following are a few an alternates versions of the Phenakistiscope.


phenakistiscope



phenakistiscope



phenakistiscope



phenakistiscope




Illusions like the Phenakistiscope

The phenakistiscope is a mechanical optical illusion. It creates the illusion of motion by rapidly displaying a sequence of still images in quick succession, exploiting the persistence of vision phenomenon.

The phenakistiscope is considered one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today.

By creating the illusion of motion through the rapid display of still images, the phenakistiscope demonstrates how the brain processes visual information and creates the perception of motion.

The phenakistiscope works by exploiting the persistence of vision, which is the phenomenon where the brain continues to perceive an image for a short period of time after it has been removed from view.

Persistence of vision is a phenomenon where the brain continues to perceive an image for a short period of time after it has been removed from view. This is due to the fact that the neurons in the visual system take a brief amount of time to process an image before they reset. As a result, if an image is presented rapidly enough, the brain will perceive a continuous image even though the individual images are no longer present.

For example, when watching a movie or animation, the individual frames are presented in rapid succession, creating the illusion of continuous motion. This is because the brain perceives the brief interval between each frame as a single, continuous image.

The persistence of vision phenomenon is important in many areas of visual perception, including motion perception, the perception of images in sequence, and the experience of visual illusions such as the Zoetrope.

Understanding the persistence of vision is essential for explaining the way that our visual system processes information and shapes our perception of the world around us.

Some related illusions include the following:

A Thaumatrope is a simple optical toy that was popular in the 19th century.

It consists of a disk with a picture or design on each side that is attached to two strings. When the strings are spun rapidly, the two pictures appear to merge into a single, continuous image.


Thaumatrope GIF


The Stepping Feet Illusion is a visual illusion that involves an optical illusion of the apparent movement of a static image.



The kinetic depth effect refers to the perception of three-dimensional (3D) depth and solidity in an object that is produced by its motion, relative to the observer.



The spinning dancer illusion is a visual illusion that depicts a silhouette of a dancer spinning clockwise or counterclockwise. The direction of the dancer’s spin can appear to change depending on the viewer’s perception.


The beta movement illusion is a visual illusion in which a series of static images, such as a filmstrip or flipbook, appears to be in motion when viewed in rapid succession.



In Peripheral Drift illusions, the image or pattern appears to move or drift, even though it is actually stationary. This movement is caused by the brain’s attempt to interpret the image or pattern, which is often complex or ambiguous. The movement can be in any direction, such as horizontally, vertically, or diagonally.



Peripheral drift illusion jelly bean
From Wikimedia Commons


The rotating snakes is a peripheral drift illusion that consists of a grid of shapes, with some of them appearing to be rotating or undulating. The illusion is created by the interaction of the shapes with the neural processing of the visual system.


Rotating Snakes Autokinetic effect
A Version of Rotating Snakes


With Illusory motion, static image appears to be moving due to the interaction of color contrasts, shapes, and position



Troxler’s fading, also known as Troxler’s effect, is a phenomenon in which a stationary visual stimulus eventually disappears from perception, even though it is still present in the visual field.



Lilac-Chaser_Troxlers Fading


The stroboscopic effect is a visual phenomenon that occurs when a rapidly flashing light is used to illuminate a moving object.

The object appears to be frozen in a single position, even though it is in motion. This is because the flashing light is only on for a brief period of time, and the object is only visible when the light is on.

Stroboscopic effect


The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.



Simultaneous Contrast Illusion


The Motion Aftereffect (also known as the Waterfall Illusion) is a visual illusion experienced after viewing a moving visual stimulus, and then fixating on a stationary stimulus. The stationary stimulus appears to move in the opposite direction to the original stimulus.

For example, fixate on the moving image below for several seconds, then shift you gaze to another surface like a plain wall. You should still be able to see the motion on the static surface.


Motion-Aftereffect



The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.


Cafe Wall Illusion



Discovery of the Phenakistiscope

The phenakistiscope was independently invented by two Belgian inventors, Joseph Plateau and Simon von Stampfer, in the early 19th century.

Plateau was a physicist who became interested in the study of optics and the way the human brain processes visual information. He discovered the persistence of vision phenomenon and began experimenting with mechanical devices that could exploit this phenomenon to create the illusion of motion.

Plateau’s invention of the phenakistiscope was one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today.

Joseph Plateau was a Belgian physicist and professor who lived in the 19th century. He is best known for his contributions to the study of optics and for inventing the phenakistiscope, a mechanical optical illusion device that creates the illusion of motion by rapidly displaying a sequence of still images in quick succession. Plateau’s invention of the phenakistiscope was one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today.

Plateau’s scientific work focused on the study of the human visual system and the way the brain processes visual information. He was one of the first scientists to discover the persistence of vision phenomenon and he used this discovery to develop the phenakistiscope. Plateau’s work has been recognized as an important contribution to the field of optics and the study of vision, and his invention of the phenakistiscope is considered a significant milestone in the history of animation and motion picture technology. Despite his many contributions to the field, Plateau is not as well-known as some of his contemporaries, such as Eadweard Muybridge, who made important contributions to the study of motion.

Von Stampfer, a mathematician and inventor, also independently came up with the idea of the phenakistiscope and is credited with popularizing the device in Germany.

Simon von Stampfer was a Belgian mathematician and inventor who lived in the early 19th century.

He is best known for independently inventing the phenakistiscope, a mechanical optical illusion device that creates the illusion of motion by rapidly displaying a sequence of still images in quick succession.

Stampfer’s invention of the phenakistiscope was one of the earliest forms of animation and helped to lay the foundation for the development of cinema as we know it today. He is also credited with popularizing the device in Germany, where it became a popular form of entertainment.

Despite his contributions to the field of animation and the development of motion picture technology, Stampfer is not as well-known as other inventors and scientists of his time, such as William George Horner, who invented the zoetrope, or Eadweard Muybridge, who made important contributions to the study of motion.

References and Resources


Check out our complete list of illusions.


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