** ** By Steven Henderson Euclid's Elements, written around 300 BC, established the fundamental axioms of geometry that would stand for over 2,000 years. Among these were Euclid's Five Postulates - simple but profound statements about the basic properties of points, lines, and planes. The first four postulates seemingly followed from intuitive observations of the physical world. However, the Fifth Postulate, also known as the parallel postulate, appeared less obvious: "If a straight...