Introduction

Abstract

We live in a world of structures. In the form of plants and animals, as well as of landscapes and clouds we are surrounded by the beautiful structures of nature (Fig. 1.1). Human civilization has added artifacts of a different kind of beauty and geometry, from the egyptian pyramids to the structures of modern urban settlements (Fig. 1.2). Modern industrial development has brought to appearance artificial structures in the form of engines and products of various types, such as airplanes, automobiles, power stations, chemical production sites and many more (Fig. 1.3). We start learning to design molecular structures, such as proteins or nucleic acids, for medical applications by experimental methods. We organize our social and economical life in societies, companies and logistical decisions.