Mathematics
Projective Geometry and the Mathematics of Perspective
Quick fact
In projective geometry, every pair of parallel lines meets at a 'point at infinity,' and these points form the 'line at infinity'—a concept that unified the geometry of perspective and led to modern computer vision.
Why this is interesting
Have you ever noticed how train tracks seem to converge at a distant point, even though you know they are parallel? That vanishing point is the gateway to a different kind of geometry.