In this optical illusion, the static pattern appears to move in a circle when viewed.
(more…)

On the left is a large black square with a smaller white square in the centre. On the right is a large white square with a smaller black square in the centre.
(more…)

This drawing is a map that was first published in 1865. The drawing is an optical illusion. At first glance, you can only recognise an eagle on a rock in the middle of some bushes.
(more…)

In a story by Mark Twain (The Innocents Aboad, 1869), the author describes the burning of millions of human mummies in Egypt as fuel for locomotives. The reason in the story for this was simply that wood and coal, which were needed to run the trains, were becoming scarce. However, mummies were plentiful in Egypt.
(more…)

Image source: https://es.m.wikipedia.org/wiki/Archivo:Borromean_Rings_Illusion.png The image of the Borromean Rings on Wikipedia is in the public domain and can therefore be used without a licence. The Borromean Rings consist of three topological circles that are linked together.

People with head lice are often wrongly accused of not taking good care of their hair. One consolation for people with head lice is that the lice are not necessarily attracted by dirty hair or scalp, as head lice actually prefer clean heads to dirty ones.

(more…)

Fresh cucumbers have a water content of almost 95.23% when freshly picked. Per 100g, cucumbers contain 15 calories. They also contain protein (0.65g per 100g), fat (0.11g per 100g), carbohydrates (3.63g per 100g), fibre (0.5g per 100g) and sugar (1.67g per 100g).
(more…)

The Fraser spiral illusion is an optical illusion that was developed by the British psychologist James Fraser in 1908. The spiral illusion consists of overlapping black and white sheets that appear to form a spiral.
(more…)

The picture shows a collection of erotic figures whose overall image merges into an illusion of face and head.
(more…)

The lattice illusion is a physiological illusion. Other such illusions are afterimages after seeing particularly bright colours and lights or striking patterns. These are caused by prolonged stimulation of the optic nerve with a particular image.
(more…)