1.
Optical illusion
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An optical illusion is an illusion caused by the visual system and characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a percept that does not tally with a measurement of the stimulus source. Pathological visual illusions arise from a pathological exaggeration in physiological visual perception mechanisms causing the aforementioned types of illusions, optical illusions are often classified into categories including the physical and the cognitive or perceptual, and contrasted with optical hallucinations. The Hermann grid illusion and Mach bands are two illusions that are best explained using a biological approach, once a receptor is active, it inhibits adjacent receptors. This inhibition creates contrast, highlighting edges, in the Hermann grid illusion the gray spots appear at the intersection because of the inhibitory response which occurs as a result of the increased dark surround. Lateral inhibition has also used to explain the Hermann grid illusion. More recent empirical approaches to optical illusions have had success in explaining optical phenomena with which theories based on lateral inhibition have struggled. A pathological visual illusion is a distortion of an external stimulus and are often diffuse. Pathological visual illusions usually occur throughout the field, suggesting global excitability or sensitivity alterations. Alternatively visual hallucination is the perception of a visual stimulus where none exists. Visual hallucinations are often from focal dysfunction and are usually transient and these symptoms may indicate an underlying disease state and necessitate seeing a medical practitioner. Etiologies associated with visual illusions include multiple types of ocular disease, migraines, hallucinogen persisting perception disorder, head trauma. If the visual illusions are diffuse and persistent, they affect the patients quality of life. These symptoms are refractory to treatment and may be caused by any of the aforementioned etiologes. There is no treatment for these visual disturbances. Cognitive illusions are commonly divided into ambiguous illusions, distorting illusions, paradox illusions, ambiguous illusions are pictures or objects that elicit a perceptual switch between the alternative interpretations. The Necker cube is an example, another instance is the Rubin vase. Distorting or geometrical-optical illusions are characterized by distortions of size, length, a striking example is the Café wall illusion
2.
Science fiction
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Science fiction often explores the potential consequences of scientific and other innovations, and has been called a literature of ideas. Science fiction is difficult to define, as it includes a range of subgenres and themes. Author and editor Damon Knight summed up the difficulty, saying science fiction is what we point to when we say it, a definition echoed by author Mark C. Glassy, who argues that the definition of science fiction is like the definition of pornography, you do not know what it is, in 1970 or 1971William Atheling Jr. According to science fiction writer Robert A, rod Serlings definition is fantasy is the impossible made probable. Science fiction is the improbable made possible, Science fiction is largely based on writing rationally about alternative possible worlds or futures. Science fiction elements include, A time setting in the future, in alternative timelines, a spatial setting or scenes in outer space, on other worlds, or on subterranean earth. Characters that include aliens, mutants, androids, or humanoid robots, futuristic or plausible technology such as ray guns, teleportation machines, and humanoid computers. Scientific principles that are new or that contradict accepted physical laws, for time travel, wormholes. New and different political or social systems, e. g. utopian, dystopian, post-scarcity, paranormal abilities such as mind control, telepathy, telekinesis Other universes or dimensions and travel between them. A product of the budding Age of Reason and the development of science itself. Isaac Asimov and Carl Sagan considered Keplers work the first science fiction story and it depicts a journey to the Moon and how the Earths motion is seen from there. Later, Edgar Allan Poe wrote a story about a flight to the moon, more examples appeared throughout the 19th century. Wells The War of the Worlds describes an invasion of late Victorian England by Martians using tripod fighting machines equipped with advanced weaponry and it is a seminal depiction of an alien invasion of Earth. In the late 19th century, the scientific romance was used in Britain to describe much of this fiction. This produced additional offshoots, such as the 1884 novella Flatland, the term would continue to be used into the early 20th century for writers such as Olaf Stapledon. In the early 20th century, pulp magazines helped develop a new generation of mainly American SF writers, influenced by Hugo Gernsback, the founder of Amazing Stories magazine. In 1912 Edgar Rice Burroughs published A Princess of Mars, the first of his series of Barsoom novels, situated on Mars
3.
Penrose triangle
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The Penrose triangle, also known as the Penrose tribar, or the impossible tribar, is an impossible object. It was first created by the Swedish artist Oscar Reutersvärd in 1934, the psychiatrist Lionel Penrose and his mathematician son Roger Penrose independently devised and popularized it in the 1950s, describing it as impossibility in its purest form. It is featured prominently in the works of artist M. C, Escher, whose earlier depictions of impossible objects partly inspired it. The tribar appears to be an object, made of three straight beams of square cross-section which meet pairwise at right angles at the vertices of the triangle they form. The beams may be broken, forming cubes or cuboids and this combination of properties cannot be realized by any 3-dimensional object in ordinary Euclidean space. Such an object can exist in certain Euclidean 3-manifolds, there also exist 3-dimensional solid shapes each of which, when viewed from a certain angle, appears the same as the 2-dimensional depiction of the Penrose triangle on this page. The term Penrose triangle can refer to the 2-dimensional depiction or the object itself. Eschers lithograph Waterfall depicts a watercourse that flows in a zigzag along the sides of two elongated Penrose triangles, so that it ends up two stories higher than it began. The resulting waterfall, forming the sides of both triangles, drives a water wheel. Escher helpfully points out that in order to keep the wheel turning some water must occasionally be added to compensate for evaporation, if a line is traced around the Penrose triangle, a 3-loop Möbius strip is formed. Although the tribar is named one of the objects, there exist many more that fit into the same category. Other impossible objects include the devils fork, the dancing elephant, three hares Penrose steps Penrose square root law An article about impossible triangle sculpture in Perth Escher for Real constructions
4.
Rhombille tiling
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In geometry, the rhombille tiling, also known as tumbling blocks, reversible cubes, or the dice lattice, is a tessellation of identical 60° rhombi on the Euclidean plane. Each rhombus has two 60° and two 120° angles, rhombi with this shape are also called diamonds. Sets of three rhombi meet at their 120° angles and sets of six rhombi meet at their 60° angles, the rhombille tiling can be seen as a subdivision of a hexagonal tiling with each hexagon divided into three rhombi meeting at the center point of the hexagon. This subdivision represents a compound tiling. It can also be seen as a subdivision of four hexagonal tilings with each divided into 12 rhombi. The diagonals of each rhomb are in the ratio 1, √3 and this is the dual tiling of the trihexagonal tiling or kagome lattice. As the dual to a tiling, it is one of eleven possible Laves tilings. It is also one of 56 possible isohedral tilings by quadrilaterals, thus, the rhombille tiling can be viewed as an example of an infinite unit distance graph and partial cube. The rhombille tiling can be interpreted as an isometric view of a set of cubes in two different ways, forming a reversible figure related to the Necker Cube. In this context it is known as the reversible cubes illusion, Escher artworks Metamorphosis I, Metamorphosis II, and Metamorphosis III Escher uses this interpretation of the tiling as a way of morphing between two- and three-dimensional forms. A human figure descends from the patio past the cubes, becoming more stylized, the rhombille tiling is also used as a design for parquetry and for floor or wall tiling, sometimes with variations in the shapes of its rhombi. It appears in ancient Greek floor mosaics from Delos and from Italian floor tilings from the 11th century, in quilting, it has been known since the 1850s as the tumbling blocks pattern, referring to the visual dissonance caused by its doubled three-dimensional interpretation. As a quilting pattern it also has other names including cubework, heavenly stairs. It has been suggested that the tumbling blocks quilt pattern was used as a signal in the Underground Railroad, see Quilts of the Underground Railroad. There is a single instance of implicit rhombille and trihexagonal tiling in English heraldry – in the Geal/e arms. In this context, it is called the Q*bert neighborhood, after the video game Q*bert which featured a view of a pyramid of cubes as its playing field. The Q*bert neighborhood may be used to support universal computation via a simulation of billiard ball computers, in condensed matter physics, the rhombille tiling is known as the dice lattice, diced lattice, or dual kagome lattice. It is one of several repeating structures used to investigate Ising models and related systems of spin interactions in diatomic crystals, the rhombille tiling has *632 symmetry, but vertices can be colored with alternating colors on the inner points leading to a *333 symmetry
5.
Wire-frame model
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A wire-frame model is a visual presentation of a 3-dimensional or physical object used in 3D computer graphics. It is created by specifying each edge of the object where two mathematically continuous smooth surfaces meet, or by connecting an objects constituent vertices using straight lines or curves. The object is projected into space by drawing lines at the location of each edge. The term wire frame comes from designers using metal wire to represent the shape of solid objects. 3D wire frame allows to construct and manipulate solids and solid surfaces, the 3D solid modeling technique efficiently draws higher quality representations of solids than the conventional line drawing. Using a wire-frame model allows visualization of the design structure of a 3D model. Traditional two-dimensional views and drawings can be created by appropriate rotation of the object, since wire-frame renderings are relatively simple and fast to calculate, they are often used in cases where a high screen frame rate is needed. When greater graphical detail is desired, surface textures can be added automatically after completion of the rendering of the wire frame. This allows the designer to quickly review solids or rotate the object to new desired views without long delays associated with more realistic rendering, the wire frame format is also well suited and widely used in programming tool paths for direct numerical control machine tools. Hand-drawn wire-frame-like illustrations date back as far as the Italian Renaissance, wire-frame models are also used as the input for computer-aided manufacturing. There are mainly three types of 3D CAD models, wire frame is one of them and it is the most abstract and least realistic. Other types of 3D CAD models are surface and solid and this method of modelling consists of only lines, points and curves defining the edges of an object. Wireframing is one of the used in geometric modelling systems. A wireframe model represents the shape of an object with its characteristic lines. There are two types of modelling, Pros and Cons. In Pros user gives a simple input to create a shape and it is useful in developing systems. While in Cons wireframe model, it does not include information about inside and outside boundary surfaces, today, wireframe models are used to define complex solid objects. The designer makes a model of a solid object, and then the CAD operator reconstructs the object
6.
Biological neural network
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In neuroscience, a biological neural network is a series of interconnected neurons whose activation defines a recognizable linear pathway. The interface through which neurons interact with their neighbors usually consists of axon terminals connected via synapses to dendrites on other neurons. If the sum of the signals into one neuron surpasses a certain threshold. Biological neural networks have inspired the design of neural networks. The first rule of neuronal learning was described by Hebb in 1949, the neuroscientists Warren Sturgis McCulloch and Walter Pitts published the first works on the processing of neural networks. They showed theoretically that networks of neurons could implement logical, arithmetic. Simplified models of neurons were set up, now usually called perceptrons or artificial neurons. These simple models accounted for neural summation, later models also provided for excitatory and inhibitory synaptic transmission. The connections between neurons are more complex than those implemented in neural computing architectures. The basic kinds of connections between neurons are chemical synapses and electrical gap junctions, one principle by which neurons work is neural summation, i. e. potentials at the post synaptic membrane will sum up in the cell body. If the depolarization of the neuron at the axon goes above threshold an action potential will occur that travels down the axon to the endings to transmit a signal to other neurons. Excitatory and inhibitory synaptic transmission is realized mostly by inhibitory postsynaptic potentials, on the electrophysiological level, there are various phenomena which alter the response characteristics of individual synapses and individual neurons. These are often divided into short-term plasticity and long-term plasticity, long-term synaptic plasticity is often contended to be the most likely memory substrate. Usually the term neuroplasticity refers to changes in the brain that are caused by activity or experience, connections display temporal and spatial characteristics. Temporal characteristics refer to the continuously modified activity-dependent efficacy of synaptic transmission and it has been observed in several studies that the synaptic efficacy of this transmission can undergo short-term increase or decrease according to the activity of the presynaptic neuron. LTP is induced by a series of action potentials which cause a variety of biochemical responses, eventually, the reactions cause the expression of new receptors on the cellular membranes of the postsynaptic neurons or increase the efficacy of the existing receptors through phosphorylation. In some cells, however, neural backpropagation does occur through the dendritic arbor and may have important effects on synaptic plasticity, a neuron in the brain requires a single signal to a neuromuscular junction to stimulate contraction of the postsynaptic muscle cell. In the spinal cord, however, at least 75 afferent neurons are required to produce firing and this picture is further complicated by variation in time constant between neurons, as some cells can experience their EPSPs over a wider period of time than others
7.
Jastrow illusion
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The Jastrow illusion is an optical illusion attributed to the Polish-American psychologist Joseph Jastrow. This optical illusion is known under different names, Ring-Segment illusion, Jastrow illusion, the illusion also occurs in the real world. In the illustration on the right, the two toy railway tracks are identical, although the one appears to be larger. There are three competing theories on how this illusion occurs and this illusion is often included in magic kits and several versions are sold in magic shops and is commonly known under the name Boomerang Illusion. The oldest reference to this illusion can be found in The World of Wonders, the two arches are placed on top of each other. They are similar in size, but not the same, the inner radius of the upper arch is the same as the outer radius of the lower arch. The first psychologist to describe this illusion was not German psychologist Franz Müller-Lyer in 1889 and his article presents a collection of geometrical illusions of size, including what is now known as the Müller-Lyer illusion. His paper also includes the segments which we now know as the Jastrow Illusion. Joseph Jastrow extensively researched optical illusions, one of his most famous creations is the Duck-Rabbit illusion, an image that can be interpreted as being both a rabbit or a duck. In 1892 he published a paper which introduced his version of what is now known as the Jastrow illusion and his version is different to the commonly used figure because the two arches taper to one end. On the other side of the Atlantic, German scientist Wilhelm Wundt was also pioneering in psychology research and he wrote one of the first books about geometric optical illusions in which he copied the design previously published by Müller-Lyer. There are several competing explanations of why the brain perceives the difference in size between the segments, none of which has been accepted as definitive. One explanation relates to how the mind interprets the two-dimensional images on the retina as a three-dimensional world, another explanation relates to the fact that the mind can only attend to a small field of vision, which is reconstructed by our consciousness. The most commonly used explanation is that the brain is confused by the difference in size between the large and the small radius, the short side makes the long side appear longer, and the long side makes the short side appear even shorter. The Jastrow illusion has been compared with optical illusions, such as the Fat Face illusion, the Leaning Tower illusion. Masaki Tomonaga, a researcher at Kyoto University, compared the Jastrow Illusion with the so-called Fat Face Illusion and he conducted experiments with people and chimpanzees to compare this illusion with the classical Jastrow Illusion. Animals are known to many of the same optical illusions as humans do. The Fat Face illusion happens when two identical images of the face are aligned vertically, the face at the bottom appears fatter
8.
Ambiguity
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Ambiguity is a type of uncertainty of meaning in which several interpretations are plausible. It is thus an attribute of any idea or statement whose intended meaning cannot be resolved according to a rule or process with a finite number of steps. The concept of ambiguity is contrasted with vagueness. In ambiguity, specific and distinct interpretations are permitted, whereas with information that is vague, context may play a role in resolving ambiguity. For example, the piece of information may be ambiguous in one context. The lexical ambiguity of a word or phrase pertains to its more than one meaning in the language to which the word belongs. Meaning here refers to whatever should be captured by a good dictionary, for instance, the word bank has several distinct lexical definitions, including financial institution and edge of a river. Another example is as in apothecary, one could say I bought herbs from the apothecary. This could mean one actually spoke to the apothecary or went to the apothecary, the context in which an ambiguous word is used often makes it evident which of the meanings is intended. If, for instance, someone says I buried $100 in the bank, however, some linguistic contexts do not provide sufficient information to disambiguate a used word. Lexical ambiguity can be addressed by algorithmic methods that automatically associate the meaning with a word in context. The use of multi-defined words requires the author or speaker to clarify their context, the goal of clear concise communication is that the receiver have no misunderstanding about what was meant to be conveyed. Ambiguity is a tool of political science. More problematic are words whose senses express closely related concepts, good, for example, can mean useful or functional, exemplary, pleasing, moral, righteous, etc. I have a daughter is not clear about which sense is intended. The various ways to apply prefixes and suffixes can also create ambiguity, syntactic ambiguity arises when a sentence can have two different meanings because of the structure of the sentence—its syntax. This is often due to an expression, such as a prepositional phrase. He ate the cookies on the couch, for example, could mean that he ate those cookies that were on the couch, to get in, you will need an entrance fee of $10 or your voucher and your drivers license
9.
Ambiguous image
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Ambiguous images or reversible figures are optical illusion images which exploit graphical similarities and other properties of visual system interpretation between two or more distinct image forms. These are famous for inducing the phenomenon of multistable perception, multistable perception is the occurrence of an image being able to provide multiple, although stable, perceptions. Classic examples of this are the rabbit-duck and the Rubin vase, ambiguous images are important to the field of psychology because they are often research tools used in experiments. There is varying evidence on whether ambiguous images can be represented mentally, the rabbit-duck image seems to be one of the earliest of this type, first published in Fliegende Blätter, a German humor magazine. Middle vision is the stage in visual processing that combines all the features in the scene into distinct. This stage of vision comes before high-level vision and after early vision, when perceiving and recognizing images, mid-level vision comes into use when we need to classify the object we are seeing. Higher-level vision is used when the object classified must now be recognized as a member of its group. For example, through mid-level vision we perceive a face, then through high-level vision we recognize a face of a familiar person, mid-level vision and high-level vision are crucial for understanding a reality that is filled with ambiguous perceptual inputs. When we see an image, the first thing we do is attempt to organize all the parts of the scene into different groups, to do this, one of the most basic methods used is finding the edges. Edges can include obvious perceptions such as the edge of a house, when finding edges, the brains visual system detects a point on the image with a sharp contrast of lighting. Being able to detect the location of the edge of an object aids in recognizing the object, in ambiguous images, detecting edges still seems natural to the person perceiving the image. However, the brain undergoes deeper processing to resolve the ambiguity, for example, consider an image that involves an opposite change in magnitude of luminance between the object and the background. The opposing gradients will eventually come to a point where there is a degree of luminance of the object. At this point, there is no edge to be perceived, to counter this, the visual system connects the image as a whole rather than a set of edges, allowing one to see an object rather than edges and non-edges. Although there is no image to be seen, the brain is able to accomplish this because of its understanding of the physical world. In ambiguous images, an illusion is produced from illusory contours. An illusory contour is a perceived contour without the presence of a physical gradient and these illusory contours are processed by the brain in a similar way as real contours. The visual system accomplishes this by making inferences beyond the information that is presented in much the way as the luminance gradient
10.
Ebbinghaus illusion
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The Ebbinghaus illusion or Titchener circles is an optical illusion of relative size perception. Named for its discoverer, the German psychologist Hermann Ebbinghaus, the illusion was popularized in the English-speaking world by Edward B, Titchener in a 1901 textbook of experimental psychology, hence its alternative Titchener circles. In the best-known version of the illusion, two circles of size are placed near to each other, and one is surrounded by large circles while the other is surrounded by small circles. As a result of the juxtaposition of circles, the circle surrounded by large circles appears smaller than the central circle surrounded by small circles. The Ebbinghaus illusion has played a role in the debate over the existence of separate pathways in the brain for perception and action. It has been argued that the Ebbinghaus illusion distorts perception of size, a study by neuroscientist Melvyn A. Developmental research suggests that the illusion is dependent on context-sensitivity, the winner of the 2014 Best Illusion of the Year Contest, submitted by Christopher D. Blair, Gideon P. Caplovitz, and Ryan E. B. Mruczek, of the University of Nevada Reno, animated the Ebbinghaus illusion, a new interesting relative size illusion was discovered by Italian visual researcher Gianni A. Sarcone in 2013. This illusion called Sarcone’s Crosses contradicts Ebbinghaus illusion and Obonai square illusion, in fact, the central test shape surrounded by large squares appears larger instead of smaller. Sarcones cross illusion consists of a surrounded by sets of squares of distinct size. As shown in the diagram opposite, the three crosses are exactly the same size, however, the one on the left tends to appear larger. The illusion works even when the small squares completely occlude the blue cross, in conclusion, there isn’t always correlation between the size of the surrounding shapes and the relative size perception of the test shape
11.
Impossible trident
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An impossible trident, also known as an impossible fork, a blivet, poiuyt, devils tuning fork, etc. is a drawing of an impossible object, a kind of an optical illusion. It appears to have three prongs at one end which then mysteriously transform into two rectangular prongs at the other end. Escher used these types of figures as the basis for impossible three-dimensional compositions in many of his woodcut prints, in 1964 D. H. Schuster reported that he noticed an ambiguous figure of a new kind in the advertising section of an aviation journal. He dubbed it a three-stick clevis and he described the novelty as follows, Unlike other ambiguous drawings, an actual shift in visual fixation is involved in its perception and resolution. The word poiuyt appeared on the March 1965 cover of Mad magazine bearing the four-eyed Alfred E. Neuman balancing the impossible fork on his finger with caption Introducing The Mad Poiuyt, the term blivet for the impossible fork was popularized by Worm Runners Digest magazine. In 1967 Harold Baldwin published there an article, Building better blivets and he explained the term as follows, The blivet was first discovered in 1892 in Pfulingen, Germany, by a cross-eyed dwarf named Erasmus Wolfgang Blivet. He also published there a sequel, Blivets — the Makings
