Landmark Papers 2 : Structure Topology

The question of what is matter has fascinated the human race for thousands of years, and continues to fascinate us today: what is it made of, and how does it behave? Early in our history, the character of natural materials was of critical importance to us, and it is no accident that we date the prehistory of humanity by the materials with which our predecessors made their tools. Tools are one of the more enduring creations of our prehistoric ancestors, and are of particular historical significance as they document the increasing technological sophistication of the human race. From the Stone Age to the Bronze Age to the Iron Age, there was an increasing awareness of the diversity of natural materials, how they could be used, and eventually, how they could be processed in order to provide even more technologically effective materials for our use. This increasing reliance on rocks and minerals required that more and more people be conversant with these materials and their properties. The atomistic theory of the Greeks was a solely philosophical construct, and further development had to await a more sophisticated approach to Science. The first steps in this direction were taken by who else but Isaac Newton (1643-1727 AD). Although his ideas on action at a distance initially referred to planets, he also considered them as applying to atoms, and concluded from physical evidence involving surface tension and viscosity that there must be strong attractions between atoms. In what must be considered as insight of legendary proportions, Roger Joseph Boscovich (1711-1787), a Jesuit mathematician from Croatia, proposed that at very short distances, atoms repulse each other, the repulsion increasing indefinitely as the particles become closer together, whereas at longer distances apart, atoms oscillate between attraction and repulsion. Frank Hawthorne uses the republication of this set of landmark papers as a vehicle to focus on the development of key issues concerning structural connectivity in inorganic solids, of which minerals are a key component, and to look at where we are today in our understanding of crystal structure.