What part of the perimeter of the heart is longer; the one above the arrow or the one below? Solution The two parts are equally long
Category In detail
Look at these two faces that we present to you. Which of them corresponds to a man and which to a woman? Solution Most of us answer that the woman corresponds to the face that appears on the left and the man's face is what we see on the right. However, both sides are the same. A simple change in the contrast of the image makes us perceive it as a man or woman even when it is the same face.
What a snail! ... Solution To draw the parts of the snail on the bright bench, a paper had to be cut and glued in place on the top and on the side of the bench. Further back, a steel column standing in the street was incorporated to make one of the snail's horns. Performed by Julian Beeber.