In an investigation carried out by the University of Santiago de Chile, it has been found that when rolling a piece of paper, the edge of the inner paper of the tube always adopts the same aspect, regardless of the thickness of the paper or the width of the tube. This edge never follows the shape of the tube: at a given point it separates from the tube and remains against the wall in front. As they have seen that it always forms a similar angle with the wall that should be in contact by itself (24.1 degree, regardless of degree), and there is always the same angle, 125.2 degrees, between the edge of the paper and the point that separates from the tube.