A FEW SCIENTIFIC AND TECHNICAL HIGHLIGHTS FROM THE HISTORY OF LYON
As will be amply illustrated during SOSORT 2017, Vertebral Deviations today enjoys a broad range of applications, finding interfaces, not only with other domains of science such as imaging systems, but also with other disciplines, particularly genetics, physics and chemistry and more recently with economics and social sciences.
In this context, it is worth highlighting a few scientific and technical breakthroughs realized in Lyon during its history, which will hopefully stimulate the curiosity of many of the meeting participants. These discoveries and inventions show that, while breakthroughs in fundamental research often lead to useful applications, the reverse is equally true; that technical developments very often improve our scientific knowledge, before any deep understanding of the underlying theories has been developed. The subsequent selection of course is arbitrary, but we hope that by emphasizing a few points it will help participants to have both an instructive and an enjoyable stay in Lyon.
Soon after the foundation of Lugdunum in 43 bc., the Romans began the construction of an impressive network of aqueducts for supplying the city with water. The longest and most technically advanced of which was the Gier aqueduct with a length of 86 kms, bringing water from the source of river Gier to Fourvière, the hill overlooking the centre of the city, called at that time the hill of god Lug. The aqueduct had a mean slope of 1 metre per kilometer, with water flowing at a speed of the order of 1 meter per second, giving a flow rate of around 15 000 cubic meters per day. The engineers had to deal with many problems set by the topographic constraints and obstacles along the route. They constructed 11 tunnels, 30 bridges, and in particular, four macroscopic siphons, which constituted a considerable technological and scientific breakthrough at that time. A siphon allows water to cross valleys, up to one hundred meters in depth, through water pipes made with lead. The pressure drop due to dissipation was relatively small, leading to only a few meters difference in height between the two tanks upstream and downstream from the siphon. The pressure inside the water pipes could exceed ten atmospheres at the lowest point of the longest siphon. In order to resist to the induced stress, the engineers divided the flow into several water pipes with diameters no larger than 27 cm. The water supply system of Lugdunum was considered the most important after Rome itself in the Roman empire. Nowadays, one can admire various well-conserved parts of the Gier aqueduct, in particular in Chaponost and Sainte Foy-Lès-Lyon, and discover many other features of life in Roman times at the Musée Gallo-romain of Fourvières, and the Musée Gallo-romain de Saint Romain en Gal.
Nicholas Andry (1658-1742), born in Lyon, was a French pediatrician who hated the brutal barber surgeons of his day.
At the age of 83 (a year before his death) he wrote a short book entitled Orthopaedia. Thus, in 1741 this name combined the root words for straight (orthos) and child (paedia) to create the name still used for the broad musculoskeletal field, orthopedics.
Andry believed that scoliosis was caused by asymmetric muscle tightness and, thus, helped foster the French belief in "convulsive muscular contraction" as the cause of spinal deformity. Andry stated, "It is well worth while to remark that the crookedness of the spine does not always proceed from a fault of the spine itself, but is sometimes owing to muscles of the forepart of the body being too short, whereby the spine is rendered crooked, just in the same manner as a bow is made more crooked by tying its cord tighter. Andry used rest, suspension, postural approaches, and padded corsets in his treatment of scoliosis.
Charles Gabriel Pravaz (1791–1853) thought scoliosis was due to unequal growth or activity. He criticized the Würzburg bed for being horizontal and claimed its use was not recognized by the medical authorities. He instead created extension equipment that allowed the patient to remain in the upright position and believed it was essential that the patient to be able to adjust the traction themself. Pravaz used gentle fixation for no more than 2 hours a day and with no more traction than they could bear. There were no adverse effects.
In 1835, he lived almost exclusively in Lyon to take care of "The Orthopaedic and Pneumatic Institute Bellevue."
In 1836 he became a corresponding member of the National Academy of Medicine.
In 1841 he was appointed member of the academy of sciences, arts and belles lettres de Lyon.
April 25, 1847 is made Knight of the Legion of Honour.
He died June 23, 1853 in Lyon, he was buried in the cemetery of Sainte-Foy-lès-Lyon.
André-Marie Ampère, who was born in Lyon in 1775, is one of the great historical figures in physics. He is of course well-known for his remarkable contributions to electrodynamics, but his first scientific works were dedicated to other topics. When he was a boy, he showed a great passion for mathematics, writing a treatise on conical sections. In 1802, he published a book, Considérations sur la théorie mathématique du jeu, where he proved, using probability theory that non-stop gambling always leads to ruin!
In addition to this use of probabilities, a central concept in statistical mechanics, Ampère also assumed the existence of atoms in his work, formulating, in 1814, three years after Avogadro, a form of the ideal gas law stating that different gases with the same numbers of molecules/atoms should occupy the same volume within the same conditions of pressure and temperature. However, the violent controversy within the scientific community concerning atomism discouraged Ampère from publicising his predictions. Of course it took almost another century and the statistical physics framework of Boltzmann and Gibbs before these ideas were fully accepted. Ampère's interest in electrodynamics came from an experiment by Oersted, performed at the Académie des Sciences in 1820. This motivated Ampère to perform many experiments himself, in order to understand the nature of the forces between currents and magnets. He proposed that magnetic fields all arise from microscopic currents contrarily to the hypothesis of the existence of magnetic charges inspired from electrostatics. He also showed that parallel current carrying wires attract each other and that a piece of metal can become a permanent magnet after application of a weak magnetic field. Although he had both the necessary mathematical skills and experimental results exposing the relevant physics, he never wrote down the so-called Maxwell-Ampère theorem, the reason being that he was confused by the violation of Newton's action-reaction principle by magnetic forces. The museum La maison d'Ampère in Poleymieux (http://www.amperemusee.fr/) exposes interesting aspects of both his personal life and scientific achievements, including industrial machines and apparatus which are direct applications of his discoveries.
Finally, let us end this short presentation with a still more artistic topic, but which also contains some rather nice technical aspects. The Lumière brothers, Auguste and Louis, came to Lyon with their family in 1870 when they were 8 and 6 years old respectively. Their father, who was a wealthy industrialist, encouraged them to study the Kinetoscope, a device created in 1891 by Thomas Edison, which projected films inside a small box which could be viewed by one or two people at the most. The Lumière brothers built an apparatus which could both record sequences of photos and project them on a large screen, giving the impression of continuous motion as observed by our eyes in real life!
The first projection of a moving picture created with their apparatus was held in 1895 in the Salon Indien in Paris, with an audience of 30 people. This is considered to be the launching of cinema in its modern sense, although this fact is often contested outside France! Curiously, the Lumière brothers were not very optimistic about the commercial future of the cinema, considering it to be no more than an artistic technique. Edison however already anticipated that it would become a pillar of human culture! Over and above the obvious usefulness of animated images for scientific purposes, the participants of SOSORT 2017 will enjoy a visit to the Musée Lumière and the Institut Lumière which provides some insight into the magic world of early cinema.