Through surveys researchers first determined that subjects perceive future events as being closer than past events, even if the events are equidistant.
According to Descartes, this is just as certain as it is inherent in the idea of a circle that all points of the circle are equidistant from the center.
He inserts a screw into one end, and using a piece of dental floss, crushes the paper between the threads of the screw creating a series of tiny equidistant corrugations.