Tressaud - Progress in Science, Progress in Society

Springer International Publishing AG 2018

Catherine Brchignac 1, 2

Abstract

Science progresses in a cumulative way, each step corresponding to as many changes of paradigms, with successive theories gradually approaching more general concepts. Thus, in the eighteenth century, Lavoisier, using mathematics to explain chemical reactions and express the law of mass conservation, brought chemistry into modernity. At the dawn of the twentieth century, another revolution resulted from the discovery of laws specific to properties at the atomic scale, which made it possible to understand, for instance, the laser effect, on which our modern technology is based, from medicine to defense and metrology to everyday items such as optical drives, microcomputers, and GPS. However, the values that set up our societies hardly fit the increasing speed of technological progresses. This lack of necessary distance for a more thoughtful judgment leads both to the unreasoned rejection of acquired progress such as vaccination and to harmful over-appropriation of information communication techniques when they lack the necessary critical analysis. It is therefore essential, in view of the rapid growth of science and technology, to take time to think about the values we want to give to our societies.

Keywords

The French word progrs like the English progress comes from the Latin word progressus which refers to the action of walking forward. The definition given by French dictionaries since 1694 has been any type of movement forward, increase or growth. With time, the definition evolved, and progress is now used to describe any advancement in time or development.

There is no doubt that science progresses. It does so by the accumulation of knowledge. To contribute to scientific knowledge, all the links in the chain of what has been acquired before must be known. Since Galileo, this chain has been built following the scientific method, that is to say, a confrontation between theory and experiment. This cumulative science has not developed linearly but by stages, often associated with changes in paradigms that progressively, in time, evolve toward better understanding. The successive theories gradually converge toward more general theories. Science is continually correcting what it has said wrote Victor Hugo in his book on William Shakespeare.

Progress in science reflects its history. For example, in the eighteenth century, Lavoisier who is considered historically the father of modern chemistry brought about a conceptual leap in chemistry by using mathematics to explain chemical reactions, something no one before him had formulated. His starting principle was that it is possible to write a chemical reaction in the form of an equation, a quantitative equality that can be verified by weighing the bodies before and after a reaction. The principle of conservation of mass is conveyed by the famous quote In nature nothing is created, nothing is lost, everything changes. In his Treatise on Elementary Chemistry published in 1789, Lavoisier clearly explained the law of mass conservation and clarified the concepts of simple bodies and complex compounds. A simple body cannot be reduced through decomposition by any known analytical chemistry method. Such, for instance, is the case of oxygen, nitrogen, hydrogen, carbon, zinc, and sulfur. By contrast, complex compounds can be decomposed into simple elements. Their chemical properties differ extensively from those of the simple bodies that constitute them. Lavoisier wrote chemistry advances towards its goal and towards its perfection by dividing, sub - dividing and sub - dividing again Chemistry is the science of analysis. Using logic, Lavoisier addressed the myth of transmutation, which imagined under the secret influence of alchemy that the transformation of lead into gold was possible, although no one had ever succeeded in accomplishing it. When the French Revolution started, chemistry had already emerged. On the other side of the channel, John Dalton (17661844) was interested in linking atmospheric phenomena and chemistry, and he started with the study of air. He traveled through Britain, from towns to countryside and mountains to valleys, and observed that the composition of air was everywhere the same. He wondered why the mixture of nitrogen, oxygen, and water vapor gases, which composes the air we breathe, was everywhere homogeneous and why the mixture did not separate depending on the density of its components? Like Lavoisier, he performed laboratory measurements and discovered that each component of a gas mixture behaved as if it were alone in the volume of the mixture. In 1801, he established the Law of Partial Pressures, which states that in a mixture, gases do not react with one another, they coexist. This is not the same when they interact. The German chemist Jeremias Benjamin Richter, who left the Prussian army to become a chemist, was much influenced by Lavoisier. In 1791, he wrote that the reason so little progress has been made in chemistry is due to the fact that chemists only rarely occupy themselves with mathematics and vice versa. He referred to stoichiometry as the science that measures the ratios of mass by which simple bodies bond to each other . He devoted his whole life to determining in what ratios of masses simple bodies combined with each other to give complex bodies, as did the French apothecary Joseph Proust, himself son of an apothecary in Angers. Richter like Proust showed that when two simple bodies react together to form a new compound, they only do so if the weight of one of the compounds is a simple ratio of the weight of the other compound. They concluded that the proportion in which two elements combine cannot vary in a continuous manner . At the time, this was startling. Dalton compiled all the results from previous experiments and published in 1803 the Law of Multiple Proportions, which stipulated that any complex body can only be described using simple ratios of the pure bodies that composed it, two to one, three to four, etc. He developed this much further and formulated a theory of his laws, which he published in 1808 in his treatise A New System of Chemical Philosophy . There he deliberately chose the atomic model, which dated back to Antiquity, to describe the composition of matter. Thus, when two simple bodies combine with each other to form a complex compound, the atoms of one body combine with the atoms of the other in a fixed ratio of whole numbers. With hydrogen as the element of reference to which he gave the value of 1, he published a system of atomic weights for 20 elements. Like Dalton, Mendeleev (18341907), who was 68 years younger, had a great admiration for Lavoisier. He liked the idea of identifying all the simple bodies as a first step to identifying the architecture of matter. Mendeleev was obsessed with order. He classified the 63 elements that had been discovered until then and presented his project of classification by lines and columns to the Russian Society of Chemistry on March 6, 1869. The chemical symbols of the elements were written on a line of increasing mass order, and elements with similar chemical properties were grouped in columns. He left empty boxes for elements that were as yet unknown (and that would eventually be discovered later). He even predicted some of the chemical properties of these missing elements. His intuition was that a deeper reason beyond simple classification was governing his table. He thought that the solution would come from the atom, which no one had yet observed. History proved him right. Relying on the steps overcome by Lavoisier, Dalton, and Mendeleev, chemistry progressively built its alphabet, which contributed significantly to its progress and to the invention of new materials we use today.