5. Qualitative Computing
Françoise Chaitin‐Chatelin, Elisabeth Traviesas-Cassan · Society for Industrial and Applied Mathematics eBooks · 2005
5.1 Introduction Computing is a human activity which is much more ancient than any historical record can tell, as testified by stone or bone tallies found in many prehistorical sites. It is one of the first skills to be taught to small children. However, everyone senses that there is more to computing than the multiplication table. Why do we compute? What does it mean to compute? To what end? Our technological society wants to compute more and more efficiently. The question of “how to compute” overshadows that of “why compute” in high-technology circles. And indeed the meaning of the act of computing seems to vanish, while we are gradually surrounded by a digital reality, which tends to shield us from the natural reality. It is vital therefore, more than ever, that we analyze computation through the two questions of why, as well as how. This can lead the way toward a better understanding of intensive computer simulations in particular and of the dynamics of evolution in general. These two questions about computation have many different facets which are all interrelated. We refer to them under the global umbrella term of Qualitative Computing. 5.2 Numbers as Building Blocks for Computation Natural integers such as 1, 2, 3, … are recorded to have emerged in Sumer in the 3rd Millennium BC, where scribes were skilled in basis 60. They used a positional representation and had a special mark for missing digits. However, neither them, nor the Greeks, who were the great computer scientists of the times, had the concept of zero, which is today so evident to us. Why?