ZERO. Is the presence of nothing different from the absence of something? Does the term “ground zero” mean the beginning or the end? Are you comfortable with empty space? Zero is both a number and a concept. Many historians state that the introduction of zero was the most significant achievement in the development of our counting system because it made calculation with large numbers feasible. The inclusion of zero introduced negative numbers and opened up a new world of mathematics, astronomy, physics, chemistry and business.