25. Brick Wall Illusion Our brain relies on memory and asks ”what is likely?” when the information is vague. Here, the object in question is unusual in a brick wall. Also, the photo is taken from an angle that the object aligns with the mortar gap. But once you have seen it, the slight deviations from a mortar gap become obvious. Furthermore, your brain has changed. Examine the brick wall. There is an object that is not expected to be in a brick wall. What and where is it? Resist the temptation to repeatedly click the mouse because once you see it, you cannot unsee it. Can you find something unusual in this picture? The black spots on the cow are shaped like 2 faces. www.mastermathmentor.com
26. Tusi Motion Illusion But if you follow one circle, you realize that it is moving back and forth on a straight line. This phenomenon was named after the 13-century Persian astronomer, Nasir al Din Tsui. Describe what you see in this animation. Most people see a wheel, consisting of colored circles, rotating within a larger wheel. www.mastermathmentor.com
27. Pyramid Illusion The image actually contains a number of superimposed squares which become lighter, the smaller they are. When there are only 7 or fewer, the edges of each square has constant brightness throughout. When their number increases, there is a seeming lightening at the edges, forming the ‘X’. Describe what you see in the figure to the right. Most people will describe this as a red square with a white X in the center. 3 squares 7 squares 60 squares 10 squares 30 squares www.mastermathmentor.com
28. Lilac Chaser Illusion To the right, you see a circle of violet disks, one of which disappears briefly when you click. Fixate on the cross and you might see a rotating green spot. If you really concentrate, the violet disks will disappear completely, leaving only the rotating green spot. Let your gaze rest of the center X but observe with your peripheral vision just when they disappear. You should see a greenish color when the violet disk disappears. www.mastermathmentor.com
29. Carport Illusion You see a carport with a roof. Look at the edge of the roof in the image and in the mirror image. How could this be? Your brain got tricked. When the image is rotated, you see the actual shape of the roof. The brain makes the assumption that the curvature of the roof will continue and would mean plan perpendicular to the axis of the roof. This is similar to the Penrose and Waterfall illusions. www.mastermathmentor.com
Sources 25. Brick wall - https://michaelbach.de/ot/cog-brickWall/ 26. Tusi - https://michaelbach.de/ot/mot-Tusi/index.html 27. Pyramid https://michaelbach.de/ot/lum-pyramid/index.html 28. Lilac Chaser- https://michaelbach.de/ot/col-lilacChaser/index.html 29. Carport - https://www.youtube.com/watch?v=KtA6u1HIqbg www.mastermathmentor.com