Synthese (1970s?)

[Music] The fabric of science should be considered in the same way as that of nature. Everything in it is infinite but everything in it is necessary. George Kuvier 1769 to 1832 [Music] portrait in soil where salt water comes to the surface. plants disappear because they can't adapt themselves with the exception of very special plants like the small salt wart which manages to adapt itself where all others have disappeared and in this industrial area Lraine a traditional salt region for a long time now totally strange areas can be seen where the vegetation has changed completely in aspect and where only some species that are found on the coast can oddly enough survive because they have managed to adapt themselves to the salt Jean Marary Pelt. My name is Jean Marary Pelt. I'm of countrytock. My family were gardeners. I studied pharmacy first, then science, and at the same time a good deal of botany. I was in turn assistant, assistant lecturer, professor. I pursued parallel scientific and sociopolitical careers, if it's possible to say that, which landed me at the Mets town hall as deputy mayor. plant biology. The choice of biological indicators offers the immense advantage of allowing a very rapid determination and immediate observations over very wide areas. Plant biology taught me a lot about biology, pure and simple. The more I thought about it while studying flowers, the more I became aware that the principal laws which govern them are the same that govern us. [Music] So one finds a kind of deep sympathy and a sense of belonging. These feelings are now feelings of great tenderness and of delicacy in a world which is very harsh. plant and [Music] man. Development of plant sexuality was the first of a series of works for which I was responsible that I christened plant and man. And well, we've seen plants make remarkable discoveries. We've seen them leave the water and adapt to life on Earth. Then we've seen them create wood, which has allowed them to become larger and become trees. And we've seen them make seeds which have enabled them to wait sometimes years for the right conditions for germinating. So we have a series of stages which makes up one gigantic epic pollution. [Music] I often say we've reached an age of autotoxicity and there's no doubt that the time has come to sound the [Music] alarm. Ecology So with some friends I founded a European institute of ecology at Mets in Lraine. Our aim in creating this institute was to develop all research and teaching activities and also practical intervention in the field with a view to improving the quality of life and protecting the environment. [Music] We've brought in biologists and specialists in human sciences because it's the only way of achieving a comprehensive vision. And here we wanted to demonstrate that in 700y old quarters we could create a science for the [Music] future. When you look at a tree trunk, the further you get from the centers of pollution, the more lychans you see reappearing. And not just any. You can practically see the level of sulfur dioxide in the air. And you can actually draw a map of air pollution. [Music] [Music] Though science is neutral, man himself is not. He is committed by the discoveries he makes and their consequences. So for me, the scientist's duty is the most objective and stringent research possible on the one hand and reflection on that research on the other. [Music] in the [Music] news. Infrared rays, ultra high frequency beams, interference, and so on pose a visualization problem. The Center for Nuclear Studies at Fontine Rose has perfected a device that achieves it. It's a liquid crystal [Music] camera. The sensitive part of this device comprises a 25 square cm screen with a low thermic capacity covered with cholesteric crystals. [Music] The sensitive surface is lit continuously for visual observation or by flash for [Music] photography. A flow of water keeps the temperature of the screen constant. [Music] This camera allows the mode of oscillation of infrared lasers, for example, to be studied. With the beam aligned, a series of photographs can be taken by two simultaneously adjustable cameras. Direct observation is equally [Music] feasible. Other areas of use, ultra highfrequency beams, interference, holography, the heating of electronic pieces or components. [Music] [Music] technology. Geothermic energy [Music] The earth contains heat. In the sedimentary basins, the temperature increase in relation to depth is an average 3° centigrade per 100 m. In some areas bound to the major faults on the Earth's crust, there are heightened geothermic gradients, the use of which can be very advantageous. Type of deposit, steam. [Music] An example in Guadaloop in the so-called Want Rainwater seeps into and circulates in the soil to reach the warm zone. As in a huge water heater, thermic convection currents are created. Being completely covered with porous rock, none of the convection heat can escape and so the temperature rises along with the pressure. Hot springs, fummeralss, and gizers can sometimes be seen on the surface escaping through natural fissures. If a well is sunk to the rock reservoir, steam can be produced. In ideal cases, this steam can be used directly to turn turbines. Type of deposit liquids. The most frequent deposits are low temperature geothermics such as the case in sedimentary basins like Alsace, Aquitane, Breast and the Parisian basin. Here the geological layer acts like a sponge 7,000 km square in which is stocked according to the studies of the BRGM a reservoir of millions and millions of calories which has kept 30 million people warm for thousands of years. It's located between 1500 and 2,000 m down and has a temperature of 65 to 85° centigrade. It can be used for urban heating in New Towns as at [Music] Mela. An installation has been set up by the society which heats 2,000 buildings. principle. The water has a high mineral salt content and so is very corrosive and can't be fed directly into domestic radiators. It has to be passed through heat exchangers. [Music] Water in the stratum is restocked by the seepage of rainwater which occurs on the periphery of the Paris basin where the porous layers are level. But this restocking is too slow to compensate for artificial tapping. So a method of reinjection dublets has to be used. On the right, a well for hot water [Music] extraction. A pressure of 7 kg provides 100 cubic m of water an hour at 72° centigrade. [Music] On the left, a well for reinjecting cold [Music] [Applause] water. A pressure of 14 kg. That's what prevents a too rapid lowering of pressure in the deposit. [Music] The Earth's heat represents one of the biggest sources of energy for the future. [Music] Medson. [Music] The hand. Man is intelligent because he has a hand. This sally of anacuric wisdom underlines the value of that wonderfully complex instrument, the hand. [Music] As an executive organ, its prime function is gripping. Its representation occupies a significant part of the cerebral structure. As a sense organ, it transmits all information, including what is needed for gripping. [Music] And this information returns to the aector to allow it its regulation and [Music] control. Only the extreme complexity of the muscular formations which guarantee the systems function allow a really functional programming of voluntary acts. That's why the surgeon has to preserve the hands sensitivity for without it the motor function is nothing. [Music] specific surgery. Each year in Europe about 1 million people suffer hand injuries and the hand is injured in onethird of working accidents, badly reduced fractures, [Music] mutilations, serious burns. For a long time, surgery has intervened in traumatic afflictions. Osteocynthesis and GPHs have proved their effectiveness. For 10 years, scientific progress has allowed practitioners like Professor Ral Tubana in Paris to operate on pathological cases, congenital mal forations, paralysis, neurological lesions, rheumatic hands. From the most common rheumatoid arthritis to the most rare [Music] lupus. Operated on a fortnight ago, this badly burned hand is on the road to recovering a function that the other still exercises. With such stiffness in hyperextension, there is only one solution to make implants. rheumatic surgery. This hand, its articulations destroyed, can only regain its function through arroplasty of the interfallangial joints. The operation consists of placing the implants between the first and second falange. [Music] It's essential to save as much of the extensor system as possible. [Music] Preparation of the conicle openings which will receive the implants. [Music] Adjustment on a model. The silicon prothesis is inert and resistant. [Music] I don't see you. All right, come to assist. [Music] 5 days after the operation, the plaster was taken off this hand. Today, re-education begins and in a month, the fingers will have regained a 70° flexion. Is it on there? [Music] This surgery still developing is being called on to render considerable service given the frequency of injuries to the hand an indispensable organ for [Music] man science. They aren't found in the waters of our regions. They come from South America or Africa. But in the CNRS laboratories at Jifet, researchers in sensory neurohysiology are studying these farraveled fish. Different aspects, morphology, electrphysiology, analysis of phenomena. An environment as realistic as possible is recreated so that the behavior of these fish in their natural surroundings can be determined. Electric fish. These fish are real electric cells. Certain species produce a strong discharge up to 600 volts with a potential of up to 6 kW. Whether in fresh water or in their marine environment, these electric fish use their discharge as a means of attack or defense. When hunting, they paralyze their prey. before swallowing it. Others like the electroforus, the South American electric eel, have two discharges, one strong which is used as a weapon, the one weak, which is given off continuously. Weak discharge fish. There are also electric fish which only have a weak discharge. The gymnark has a regular emission. The Morous an irregular emission. This weak discharge about 1 volt can be made audible and visible on an oscilloscope. This discharge creates an electrical field around the fish which enables it to recognize the nature of objects in its surroundings. The fish will go through the plastic ring. On the other hand, it refuses to go through an identical metal rimmed ring. Group experiments produced a similar result. Indifference to plastic, avoiding metal, the fish is capable of distinguishing between objects of different conductivity. Environmental analysis by auto stimulation. Its electroensory system which makes it sensitive to any modification in its electrical field enables it to localize an object. The fish possesses specialized organs electro receptors. The emission of the discharge creates a field which stimulates the cutaneous receptors. It is in fact auto stimulation. [Music] When an object disturbs the electrical field, the receptors aware of the modification inform the brain. Social communication. But these fish are not only sensitive to their own field. They are equally sensitive to those created by their conjenerics. If an electrical charge is produced artificially, the fish interrupts its own discharge, then renews it. This is a fish auto [Music] stimulating. But the discharge emitted by another fish is also intercepted by the receptors which inform the brain. This one stops the process of auto stimulation to listen to the emission of the conjeneric then [Music] replies. So a kind of communication is established between the two fish each expressing itself in a different way while listening to its partner. [Music] The study of the functioning of these sensory mechanisms helps towards the understanding of the most complex physiological phenomena. [Music]