10 most difficult illusions riddlesOptical illusions quiz
The bright circle around the Sun seen in the picture is known as a halo. What causes it?
refraction of light in ice crystals
refraction in the lens of the eye or lens
refraction of light in water drops
reflections from the water surface
Halo is the name for a family of optical phenomena produced by light interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Among the best known halo types are the circular halo (properly called the 22° halo), Other common optical phenomena involving water droplets rather than ice crystals include the glory and the rainbow.
Which of the lines on the right, is the continuation of the black line on the left?
none of them
both of them
This is known as Poggendorff illusion, first described in 1860. Many detailed studies of the illusion point to its principal cause: acute angles in the figure are seen by viewers as expanded.
What shape does Ames' room have?
There are two illusions associated with the Ames Room. First the room appears cubic when viewed monocularly from a special viewing point (the true shape of the room is trapezoidal). Secondly, within an Ames Room people or objects can appear to grow or shrink when moving from one corner to the other.
This is a rare phenomenon called iridescent clouds. It occurs in the clouds with ...
small droplets or ice crystals
The effect is similar to irisation. Iridescent clouds are a diffraction phenomenon caused by small water droplets or small ice crystals individually scattering light. Larger ice crystals do not produce iridescence, but can cause halos, a different phenomenon.
How is this polygon called? (the one over the circles)
In this Ehrenstein illusion the sides of a square placed inside a pattern of concentric circles take an apparent curved shape. But in reality, the sides are straight.
Which continent is that?
This is Australia map, with north at the bottom side.
Which area is brighter?
Both are the same
It depends on the order of seeing
This is the well known checker shadow illusion, first published in 1995 by Edward H. Adelson, Professor of Vision Science at MIT. The area A appears darker because of its light surrounding. At the same time, area B, surrounded with dark areas, appear lighter.
Whose face has been combined with Albert Einstein in this hybrid image?
A Hybrid Image is an optical illusion developed at MIT in which an image can be interpreted in one of two different ways depending on viewing distance. In order to see Marylin clearly, you need to move away of the screen