Optics principles. For example, the Ames room, Hering, Müller-Lyer, Orbison, Ponzo, Sander, and Wundt illusions all rely on the suggestion of the appearance of distance by using converging and diverging lines, in the same way that parallel light rays (or indeed any set of parallel lines) appear to converge at a vanishing point at infinity in two-dimensionally rendered images with artistic perspective. This suggestion is also responsible for the famous moon illusion where the moon, despite having essentially the same angular size, appears much larger near the horizon than it does at zenith. This illusion so confounded Ptolemy that he incorrectly
Point-to-point (steeplechase) Point-to-point (steeplechase) A point-to-point is a form of horseracing over fences for hunting horses and amateur riders. In Ireland, where the sport is open to licensed - i.e. professional - trainers, many of the horses will appear in these races before they compete in National Hunt races. Consequently, the Irish point-to-point is more used as a nursery for future young stars: a horse that wins its debut point-to-point in Ireland will often sell for a lot of money. Whilst professional trainers are specifically excluded from running horses in point-to-points in Great Britain (other than their own personal horses), the days