title: Real life usage of the projective plane theory
body: <p>I'm learning about the theory of the <a href="http://en.wikipedia.org/wiki/Projective_plane" rel="nofollow noreferrer">projective plane</a>. Very generally speaking, it is an extension of the plane, which includes additional points which are defined as the intersection points of two parallel lines. In the projective plane, every two lines have an interesection point. Whether they're parallel or not. Every point in the projective plane can be represented by three numbers (you actually need less than that, but nevemind now).</p>
  
  <p>Is there any real life application which uses the projective plane? I can think that, for instance, a software which needs to find the intersections of a line, can benefit from always having an intersection point which might lead to simpler code, but is it really used?</p>