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background_energy.pdf Background for stories concerning energy 1 Storytelling Teaching Model: http://science-story-telling.eu Background for stories concerning energy From the educational point of view, there appear to be three aspects which are relevant with respect to teaching energy in lower secondary school: Energy as a concept, together with energy conservation, re- newable energy, and energy efficiency. The aim of this historical background is to form a basis for stories that may be used individually or combined, and that enable teachers to address these three aspects. The historian and philosopher of science Thomas Kuhn pointed out that up to twelve researchers can be identified as being involved in the establish- ment of the principle of energy conservation (Kuhn 1959). One of those researchers, James Prescott Joule, can be seen as a central figure to this background. Joule is a central figure as he is the person who established the mechanical equiva- lent of heat – at least this is the standard notion. However, if one takes a closer look, then it gets evident that it was not just Joule who is responsi- ble for establishing his work, but also William Thomson, who later became Lord Kelvin. Yet, Joule himself did not start from scratch and par- ticularly referred to the work of Benjamin Thomp- son, Count Rumford, who carried out researches about heat in late 18 th / early 19 th century. Actually these researchers were more oriented on practical purposes than those of Joule. The first significant aim towards renewable energies can be seen in the work of the French teacher Augustin Mouchot who, in the 1870ies carried out substantial re- search on using solar energy for industrial ma- chinery. Count Rumford and his work on heat Rumford’s work on heat covers a huge variety of researches; he worked significantly on the topic for some 25 years. His first research in this respect resulted from his military context: he examined the quality of powder (Thompson 1781). In doing so, he suspended the cannon as well as a ballistic pendulum, the amplitude of the oscillation after firing the powder served as an indication of its quality. Whilst the initial research in not that important with respect to energy, one detail actually is: Rumford observed that the cannon heated up most when he did not shoot a bullet but just made the gunpowder explode in the barrel. When being in Munich and having the responsibility for the pro- duction of weaponry, Rumford made another ob- servation that he turned into an experiment: In the process of cannon-boring, the metal heated up. Rumford used a blunt drill in order to increase the Fig. 1: Rumford’s experiment on the quality of gun-powder. (Thompson 1781) 2 Background for stories concerning energy Storytelling Teaching Model: http://science-story-telling.eu heat production. In doing so, he was able to heat up the water (and that was a mass of 26.58 lb) that was initially intended for cooling to the boiling point (Thompson 1798). At the same time, Rumford demonstrated that the heat capacity of the metallic chips that were pro- duced in the process of drilling was not changed in their heat capacity. From his experiments, Rum- ford concluded that heat can be produced from mechanical work in an unlimited amount – as the production of material substances was not in ac- cordance with the accepted understanding, he had also to conclude that heat is not a substance but the motion of the smallest particles of matter. Doing so brought him in conflict with the most recent accepted doctrine with respect to heat: In 1789 the French chemist Antoine Laurent Lavoi- sier published his famous Traité Élémentaire de Chimie … (Lavoisier 1789). In this monograph as well as in a variety of research papers Lavoisier used the term caloric. For Lavoisier, caloric was one of the "simple substances belonging to all the kingdoms of nature, which may be considered as the elements of bodies" (Lavoisier 1790, p. 175). This substance was said to be weightless and thus considered to be one of the imponderables. Other imponderables were the matter of light (in Lavoi- sier’s nomenclature lumic), moreover, there were one or two electric and magnetic fluids. Caloric was taken to be the explanation for the phenomena connected with heat. In some attributes caloric was very similar to the older substance named phlogiston, although there were important differ- ences between Lavoisier's System and the one founded by Becher and Stahl. This played also a role in naming the first instrument that enabled measurements of the amount of heat calorimeter (Roberts 1991, see also Beretta 2005), the ice calorimeter. For the discussion of Rumford’s work with re- spect to energy conservation, the importance of Lavoisier's work lies not in the fact that his system can be seen as the accepted theory – and actually Rumford’s work did not change this impression significantly, on the very contrary: In the first quarter of the 19 th century, heat was a material substance and most researchers identified this substance with Lavoisier’s caloric. The im- Fig. 2 Rumford’s cannon-boring experiment (Thompson 1798). Background for stories concerning energy 3 Storytelling Teaching Model: http://science-story-telling.eu portance for Rumford’s work lies in the postulated indestructibility of the elements. As caloric was one of Lavoisier's elements (even though impon- derable, but it was listed in his system as an ele- ment such as Oxygen or Iron), it was obvious that this substance could neither be destroyed nor cre- ated. Thus the idea of conservation was estab- lished in the theory of heat. Whilst Rumford’s cannon boring experiments can be seen in direct relation to the establishment of the theory of heat, two other of his research projects appear to be relevant in the context of the project too: On the one hand, he analyzed the ra- diant heat. This became a topic in natural philoso- phy at the very beginning of the 19 th century when William Herschel (who is besides this work best known for his discovery of Uranus) came in a series of measurements to the conclusion that the radiation from the sun did not just consist of light, but also contained radiant heat which had its larg- est intensity beyond the red part of the spectrum. 1 These ‘new rays’ became an issue of investiga- tion for several researchers, most namely John Leslie who published in 1804 a monograph deal- ing with this issue. However, Rumford published 1 The background of these experiments was the idea to find out which part of the (visible) spectrum might affect lenses in a telescope in the most significant manner due to heating up the glass. also in 1804 an investigation in which he analyzed the ability of various materials to emit radiant heat. 2 Whilst this inquiry may be seen as funda- mental research, there are also aspects of applica- bility in his investigation: it was relevant with respect to the improvement of the efficiency of stoves, an issue that had been central to Rumford’s work for decades. Rumford developed an instrument that he called thermoscope. This instrument consists of a glass capillary that is U-shaped. At both ends of the capillary, hollow spheres are attached. These spheres are blackened and made from very thin glass. Due to the blackening, the glass spheres absorb radiant heat, as the glass is very thin, the absorbed heat is conducted to the air inside of the sphere. As the capillary is closed, due to the in- crease of temperature, the pressure is increased as 2 See Leslie (1804) and Thompson (1804), for a discussion of these investigations see Olson (1970). Fig. 5: Rumford’s thermoscope, Thompson 1804 Fig. 4: Herschel’s experimental set-up for the dis- covery of radiant heat, Herschel 1800. Fig. 3:Ice calorimeter by Lavoisier and Laplace (Lavoi- sier 1789), https://upload.wikimedia.org/wikipedia/ commons/3/35/Ice-calorimeter.jpg 4 Background for stories concerning energy Storytelling Teaching Model: http://science-story-telling.eu well, consequently, the pressure on each side is related to the absorbed radiant heat. In the middle of the horizontal part of the glass capillary, a drop of alcohol is placed. When the pressure in both arms is different, the drop moves towards the side of lower pressure. Consequently, the gas at lower pressure is compressed whilst the gas at higher pressure expands until pressure equal pressures are reached. Between the two spheres, a copper disc is placed, thus the heat emitted from a source that is placed in a geometrical line with the two balls can affect only one of the spheres. The thermoscope is placed on a wooden frame. On both sides, heat sources (metal cans filled with hot water) can be placed and changed in their dis- tance towards the thermoscope. At the beginning of each experiment, both heat sources are placed in the same distance. Due to the absorption of radiant heat and the resulting different pressure, the alcohol drop starts to move. The experimenter increases the distance between the stronger heat source and the thermoscope until the alcohol drop is in its initial equilibrium position. Comparing the distances of the two sources to the thermoscope serves as an indicator of their emission – Rumford took it for granted that the heat emitted from de- creases with the inverse square of the distance. This relation was already demonstrated by the Swiss mathematician Johann Heinrich Lambert for the decrease of light intensity with the distance, a work Rumford was through his own work in the field of photometry familiar with. Lambert’s rela- tion s appeared to be plausible for radiant heat as well – on the one hand due to its similarity with light, on the other as an isotropic radiation de- creases with the inverse square of the distance. Yet, the question of improving the efficiency was not limited to his work on radiant heat and stoves. Another research that can be seen in this context was his analysis of the insulating proper- ties of different materials. This analysis was also carried out whilst Rumford was minister of war in Munich, and was in a broader sense related to a military issue. The aim was to develop the basis for determining the most suitable material for the uniforms of the Bavarian soldiers who ideally would get only one type of uniform that was sup- posed to be suitable for winter as well as summer. Like in the experiment on analyzing radiant heat, Rumford used metal cans as heat sources. These cans were covered with different clothing materi- als, hot water was filled in, and Rumford observed the decrease of the waters temperature. In doing so, he was able to determine the most efficient way to insulate the human body. To summarize, Rumford can in retrospect be identified as a starting point for various develop- ment in the energy science – he carried out exper- iments that were related to the formulation of the principle of energy conservation as well as to a field that nowadays can be labeled ‘energy effi- ciency’, particularly with respect to different ma- terials. The formulation of the principle of energy con- servation Joule started his research in analyzing electri- cal motors. 3 This was directly related to his work in the brewery his father owned. Here, steam en- gines were used, and, after the development of the electrical motor, the potential of this new device seemed to be superior to the one of a steam en- gine. Consequently, Joule’s aim seemed to have been the construction of an economical electro- magnetic engine. This can be derived by the fol- lowing: "I can hardly doubt that electro- magnetism will ultimately be substituted for steam to propel machinery. ... the economy (of an en- gine) will be in direct ratio of the quantity of elec- tricity, and the costs of working the engine may be reduced ad infinitum" (Joule 1884, p. 14). This idea of an ‘economical perpetuum mobile’ is not just found in Joule’s writings, but many scholars of this time held this opinion. 4 Joule finally came 3 On the early history of electrical motors see in particular Schiffer (2008). 4 This is not to be confused with a scientific perpetuum mo- bile as it has been done e.g. by Breger: “Obviously Joule has no principal objection to a perpetuum mobile at this time; Fig. 6: Rumford’s heat radiator, Thompson 1804. Background for stories concerning energy 5 Storytelling Teaching Model: http://science-story-telling.eu to the conclusion (like other scholars) that the zinc that reacts in the galvanic element is more expen- sive than the fuel for a steam engine which is sup- posed to carry out the same work like the electri- cal motor. During the following years, the subject of Joule's research was the production heat either by voltaic electricity, in batteries or in chemical com- bustion; these investigations were quantitative. After completing this research, Joule turned to a new topic: in 1843, on the occasion of the meeting of the British Association for the Advancement of Science, Joule presented a paper° which initiated his later prestige. He described the new subject of his investigations in announcing that "having proved that heat is generated by the magneto- electrical machine, and that by means of the in- ductive power of magnetism we can diminish or increase at pleasure the heat due to chemical changes, it became an object of great interest to inquire whether a constant ratio existed between it and the rnechanical power gained or lost" (Joule 1884, p. 149). Joule performed new experiments to demonstrate the existence of a mechanical equivalent of heat and to determine its numerical value. From a first series of experiments he deter- mined the coefficient as 838 ftlb/BTU, in a second series published in the same article he gave 770 ftlb/BTU. Looking at the data Joule published gives some insight into Joule's theoretical background. The equivalents he calculated with the data in his pa- per were (in ftlb/BTU): 896; 1001; 1040; 910; 1026; 587; 742 (mean of five experiments); 860 (mean of two experiments); 770. The two bold data derive from experiments "conducted in pre- cisely the same manner" (Joule 1884, p. 153). It seems to be daring to take these data as a proof for the existence of any equivalent, in other words, Joule had to believe in the existence of a mechani- cal equivalent of heat in order to formulate this result from his data. The data could also be inter- preted as an indication that the amount of heat produced from the same mechanical work may differ significantly, depending on some unknown or at least unclear parameter. However, Joule came to the formulation that there is a mechanical equivalent of heat, and that the deviation of the data are caused by the reading limitations in his experiments: "I admit that there is a considerable difference between some of the results, but not, I think, greater than may be referred with propriety obviously he thinks that an inexhaustible source of power is practicable"(Breger 1982, p.194). to mere errors of experiment" (Joule 1884, p. 156). Although Joule realized the difference between his data, he claimed to have proved the existence of a mechanical equivalent of heat. Therefore, it seems to be plausible that he came not to believe in the existence of the equivalent from his experi- mental data but for other reasons. Towards the end of his research on this topic, Joule himself gave an insight into these reasons declaring that he was "satisfied that the great agents of nature are, by the Creator's fiat, indestructible; and whatever me- chanical force is expended, an exact equivalent of heat is always obtained" (Joule 1884, p. 158). This statement gives an imagination of the theoretical background Joule had in mind when trying to determine the mechanical equivalent of heat. For Joule it was not compatible with his view of na- ture that anything could be destroyed or created. He had embodied the idea of conservation in a way that made it impossible to accept any excep- tions of this principle. But there seemed to be several exceptions as, for example, the generation of heat by the magneto-electrical machine. There- fore, it was necessary for Joule to develop a new idea, the idea of equivalent transformation of what he called great agents of nature. This idea, the equivalent convertibility, is the great conceptual step that was necessary to come from the principle of conservation of heat (as caloric) in Lavoisier's sense to the principle of energy conservation. The paper Joule presented in 1843 was not paid much attention to in the scientific world. In the following years Joule presented several papers in which he described various different experiments he made to determine the value of the mechanical equivalent of heat with higher precision. Two of these papers are noteworthy for completely differ- ent reasons. One was published in the Philosophi- cal Transactions of 1850, it was entitled "On the Mechanical Equivalent of Heat". In this paper Joule described in full detail his experiments with the famous paddle-wheel. This paper did not only include the data Joule got from his experiments and the calculation of the mechanical equivalent, but also a detailed description of the experimental set-up. Additionally, Joule described his experi- ments on the friction of mercury and of cast iron. In a way, the publication of this paper in the pres- tigious Philosophical Transactions can be seen as a strong indicator of the acceptance of Joule’s work by the British scientific community. The other important paper Joule presented at the annual Meeting of the British Society. As his biographer D. Cardwell pointed out: "Joule be- lieved his paper would have passed without notice 6 Background for stories concerning energy Storytelling Teaching Model: http://science-story-telling.eu had not a young man at the back of the hall risen and asked penetrating questions that created a lively interest in the paper" (Cardwell 1989, p. 83). This young man was William Thomson, later Lord Kelvin. He was one of the first really influ- ential scientists, and he was the first interested in Joule's results. Although he did not agree with Joule's ideas at first, he became convinced and not only supported Joule's theory, but also started a successful collaboration with him. Thomson was skeptic about Joule’s experi- mental claims as he was trained in part in France where he became familiar with the work of Victor Regnault and Sadi Carnot. The latter had demon- strated that the work of a steam engine is depend- ing on the temperature difference, thus the work was not equivalent to a specific amount of heat, but depending on the temperature differences. Only when the concept of energy and energy dis- sipation (and in this respect entropy) had been developed, both Joule’s and Carnot’s findings were no longer in contradiction. In some sense, this contradiction together with the growing ac- ceptance of the energy concept triggered the de- velopment of the energy concept. Only during the collaboration Thomson became convinced that Joule’s results were correct and important, in the following he supported Joule in the scientific community. This aspect is relevant for the acceptance of Joule’s work in the British scientific community: Ignoring his findings may in part be explained by the fact that Joule was a brewery owner in Man- chester. Even though this turned out to be crucial for Joule’s experimental resources (which will be discussed later) it also caused a difficulty: Even though conceptual difficulties played a role, it was also Joule’s status that was meaningful. He was not a trained scientist but more a ‘gentlemen of science’ without a scientific CV or position. Whilst this was the standard during the 18 th and in the early 19 th century, in the middle of the century the situation had changed. Science became more and more professionalized in Britain, and part of this professionalization was the resulting limita- tion of science to professional practitioners. There were of course exceptions, most notably Michael Faraday, however, when Joule started publishing on the mechanical equivalent of heat, his social status was certainly an issue. On the other hand, William Thomson was well trained, a young pro- fessor at the University of Glasgow and, despite his age, already well-established in the scientific community. Thus, it was not just the individual Thomson who supported Joule’s work, but also the scientists with his status. Consequently, the support by Thomson contributed to the acknowl- edgment of Joule’s work. But it is not a question of social status that is interesting in Joule’s work: His experiments are equally remarkable. To give but a brief description on the experiment: Figure 7 is a perspective view of the set-up Joule gave in his paper. aa are wooden pulleys; l foot in diameter and 2 inches thick, with wooden rollers, bb, bb, 2 inches in diameter, and steel axles, cc, cc, one quarter of an inch in diameter. The pulleys were built per- fectly true and equal to one another. The axles were supported by brass friction wheels dddd, dddd, the axles of which worked in holes drilled into brass plates attached to a strong wooden table, which Joule affixed to the wall of his laboratory. The weights e, e, were suspended by string from the rollers bb, bb; and fine twine attached to the pulleys aa connected them with the central roller f, which, by means of a pin, could easily be attached Fig 7: Joule’s paddle wheel apparatus, Joule 1872 Background for stories concerning energy 7 Storytelling Teaching Model: http://science-story-telling.eu Figure 9: Joule’s paddle wheel, horizontal cut. Joule 1872 Figure 8: Joule’s paddle wheel, lateral cut. Joule 1872 to, or removed from, the axis of the frictional ap- paratus. This apparatus is represented in figure 8 (left) vertically and in figure 8 (right) horizontally. It consisted of a brass paddle-wheel furnished of 8 sets of 4 revolving arms each and 4 sets of 4 sta- tionary vanes each. The brass axis worked freely and was divided at d into two parts to avoid any conduction of heat in that direction. The paddle wheel firmly fitted into a copper vessel with two holes in the lid, one for the insertion of the axis, and one for the insertion of a thermometer. During the experiment a large wooden screen was at- tached to the table to avoid all effects of heat radi- ation from the experimenter. At the beginning of the experiment, the vessel is filled with water, and it needs about 6 l of water to fill this vessel. When everything is in thermal equilibrium, the temperature of the water as well as the one of the room is measured, and the ther- mometer is removed from the vessel. Then the weights of a total of 26 kg are wound up for about a meter and then go down, driving a paddle-wheel that is stirring the water. This procedure is repeat- ed twenty times, and it takes some 35 minutes to realize these 20 runs. In the end, according to Joule’s data, an increase of the water temperature of approximately 0.5°C can be measured. Analyzing this experiment reveals some details that are noteworthy and which show that Joule was in an extraordinary situation: Joule was able to employ some of the most skilled craftsmen who were at hand in an industrial town such as Man- chester. The instrument maker – John Benjamin Dancer – was extremely versed and particularly able to create extremely sensitive thermometers. Their sensitivity was extraordinary: "The two thermometers he (Joule) had acquired in 1844 were, he claimed the first accurately-calibrated thermometers in Britain … ." (Cardwell 1989, p. 234) The thermometer which was used to deter- mine the temperature of the water had a length of 87 cm and had a range from freezing point to about 85°F (see Ashworth 1930). Joule wrote that "constant practice had enabled me to read off with the naked eye to 1/20 of a division it followed that 1/200 of a degree Fahr, was an appreciable tem- perature" (Joule 1884, p. 303). At such a degree of sensitivity, water is far from being at a constant temperature. Consequently, the procedure of de- termining this temperature is far from being easy. Instead of waiting until the mercury column of the thermometer comes to rest and then read the tem- perature, Joule had to find other means to deter- mine when the thermometer and the water were in thermal equilibrium. As Sibum demonstrated, measuring temperatures was part of the brewer’s culture, thus Joule had the respective competence to carry out the measurement from his profession- al background. There are other aspects which indicate that this experiment was embedded in the brewers’ culture: Joule used a copper vessel without any insulation, even though the room should not affect the ther- mal condition of the water in any way. This may 8 Background for stories concerning energy Storytelling Teaching Model: http://science-story-telling.eu seem a bit unusual, particularly when one takes into consideration that Joule actually used a wooden shield to protect the vessel from the radia- tion of the body of the experimenter. However, the copper vessel is a device commonly used in beer brewing, thus Joule was very versed in controlling the thermal situation in such a vessel – an insulat- ed one (which could not be perfectly insulated) was not familiar as a system to Joule. But there are also material aspects in the Man- chester brewery that enabled Joule to carry out his experiment successfully. On the other hand Joule needed a room with a huge heat capacity – other- wise the heat produced by the human body in winding up the weights would affect the room temperature and thus the experimental result sig- nificantly. Such a room exists in a brewery: the cellar in which the beer is stored. This has a huge heat capacity and thus an almost uniform tempera- ture, thus it was a room with the physical proper- ties that were necessary for the production of reli- able data. On the other hand, Joule could use a brewing mate to do the work of winding up the weights. This required certain skills as the weight is heavy, and one has to be fast and controlled at the same time to do this work. Joule himself was not in the physical position of doing this work, moreover, he was a gentleman, and doing such a work would not correspond to his social status. 5 Starting research on renewable energy In mid-nineteenth century, industrialization progressed at high speed. One of the side effects was the necessity to have fuel for the seam en- gines that were the central power source in the factories. To France, this started to pose a major problem, as the coal deposits turned out to be lim- ited and were almost exhausted. This was even more a problem as the potential imports could only come from England – the traditional (eco- nomic) rival to France. Consequently, the French government promised financial support to any researcher who proposes promising concepts of how to avoid a dependency of France from Eng- lish coal. This was the moment when the French second- ary school teacher Augustin Mouchot entered the stage. Mouchot combined two devices that had been known previously: A blackened hollow cyl- inder containing water – a similar device had been used by the end of the eighteenth century by Hor- ace Benedict de Saussure for making experiments 5 Similarly, Joule did not mention the person doing the physi- cal work in the experiments he carried out afterwards which led to what is nowadays known as the Joule-Thomson-Effect (see Sichau 2000). on heat radiation. This was combined with a hol- low mirror that was used to focus solar radiation on the cylinder. Already in 1861, Mouchot was able to produce steam with his device. In the fol- lowing years, he intended to improve his set-up to make it more useful for technical purposes. The attempts were financially supported by the French government. Two outcomes can be named as direct results: On the one hand, Mouchot was able to develop solar cooking devices, items that were used in particular by the French army in their North Afri- can colonies. These devices enabled the soldiers to prepare hot meals without producing smoke, a detail relevant from a military perspective. These cookers were used until the 20 th century. The other result of Mouchot’s attempts was a steam engine that was operated with steam pro- duced by his solar apparatus. Mouchot devised several of the engines, the largest was shown at the world exhibition in Paris in 1878. The conical mirror had a diameter of some five meters, and the engine could be used as a printing device, but was also able to produce ice. Mouchot was awarded a gold medal for this ma- chine. Yet, by this time, things had changed once again. A major problem of Mouchot’s machine remained the mirror which was made with a silver coating – this tended to oxidize, thus reducing the efficiency of the machine and requiring a constant cleaning of the mirror. However, another devel- opment turned out to be far more problematic for Mouchot: Miners had found new coal deposits in Eastern France, consequently, the necessity for finding an alternative source of energy for the steam engine did not exist any longer. Moreover, in a report Mouchot’s machine was labeled as economic inefficient. As a result, the French gov- Figure 10: Mouchot’s apparatus at the Paris World Fair, http://upload.wikimedia.org/wikipedia/commons/6/66/M ouchot1878x.jpg Background for stories concerning energy 9 Storytelling Teaching Model: http://science-story-telling.eu ernment ceased to support Mouchot’s research financially; this brought his work to an end. References Ashworth JR (1930): Joule's Thermometers in the Possession of the Manchester Literary and Philosophical Society (Journal of Scientific Instruments Vol 7, No. 11, London) pp 361 - 363. Ashworth JR (1931): A List of Apparatus now in Manchester which belonged to Dr. J.P. Joule, F.R.S., with Remarks on his M.S.S., Letters, and Autobiography. In: Manchester Memoirs Vol 75, No 8, 105. Beretta M. H. (2005). Lavoisier in Perspective. München, Deutsches Museum. Breger H (1982). Die Natur als arbeitende Maschine. Brown SC (1979): Benjamin Thomson, Count Rumford (MIT Press, Cambridge, Mass., London). Goldfarb SG (1977) Rumford's Theory of Heat: A Reassess- ment. In: British Journal for the History of Science Band 10:S. 25 - 36. Heering P (1992) On J.P. Joule's Determination of the Me- chanical Equivalent of Heat. In: Hills, Skip (Ed.): The His- tory and Philosophy of Science in Science Education Vol.1, Kingston, Ontario), pp 495-505. Herschel, W. (1800). Experiments on the Refrangibility of the invisible Rays of the Sun. Philosophical Transactions of the Royal Society 90, 284-292. Joule JP (1850): On the Mechanical Equivalent of Heat. Philosophical Transactions of the Royal Society of London 140, 61-82. Reprinted in Joule JP (1884): The Scientific Papers. Joule, JP (1872). Das mechanische Wärmeäquivalent. Braun- schweig, Vieweg. Kuhn, TS (1959): Energy conservation as an example of simultaneous discovery. In: M. Clagett (ed.): Critical Prob- lems in the History of Science. University of Wisconsin Press, Madison, 321 - 356. Leslie, J. (1804): An experimental inquiry into the nature and propagation of heat. London, Printed for J. Mawman. Mouchot, Augustin (1869), La chaleur solaire et ses applica- tions industrielles. Paris. Olson RG (1970) Count Rumford, Sir John Leslie, and the Study of the Nature and Propagation of Heat at the Begin- ning of the Nineteenth Century. In: Annals of Science Band 26: 273 - 304. Roberts L. (1991). A Word and the World: ¬The Significance of Naming the Calorimeter. ISIS 82: 198 - 222. Schiffer MB (2008): Power struggles: scientific authority and the creation of practical electricity before Edison. Cam- bridge, Mass., The MIT Press. Sibum HO (1995): Reworking the Mechanical Value of Heat: Instruments of Precision and Gestures of Accuracy in Early Victorian England. Studies in the History and Philosophy of Science 26, 73 - 106. Sichau C (2000): Die Joule-Thomson-Experimente: An- merkungen zur Materialität eines Experiments. In: NTM 8:223-243. Smith C & Wise MN (1989): Energy and Empire: ¬A bio- graphical study of Lord Kelvin (Cambridge University Press, Cambridge - New York - Port Chester - Melbourne – Sydney Thompson, B (1781): New Experiments upon Gun-Powder, with Occasional Observations and Practical Inferences; To Which are Added, an Account of a New Method of Deter- mining the Velocities of All Kinds of Military Projectiles, and the Description of a Very Accurate Eprouvette for Gun-Powder. In: Philosophical Transactions of the Royal Society of London 71, 229-328 Thompson, B. (1798). "An Inquiry concerning the Source of the Heat Which is Excited by Friction. Philosophical Transactions of the Royal Society of London 88: 80-102. Thompson, B (1804): An Enquiry concerning the Nature of Heat, and the Mode of Its Communication. In: Philosophical Transactions of the Royal Society of London 94, 77-182. Background for stories concerning energy was written by Peter Heering with the support the European Commission (project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and Flensburg University, Germany. This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the infor- mation contained therein. Biography_Mouchot_ENG.pdf Biography: Augustin Bernard Mouchot 1 Storytelling Teaching Model: wiki.science-stories.org Biography: Augustin Bernard Mouchot (1825-1912) Important things that we know today about solar energy are connected with one of the inventors of a 19th century Augustin Mouchot, his life and occupational ca- reer. He was French engineer, mathematician and physicist. He was a man of enormous imagination. Mouchot was drawn to the idea of finding alternative en- ergy sources, believing that the coal fuel would eventually run out. Thus, he un- dertook research on solar energy. He was an inventor of the earliest solar powered engine, converting solar energy into mechanical stem power. Solar cooking was his another field of investigations. Exploring solar cooking he used works of Hor- ace-Benedict de Saussure and Claude Pouillet. Mouchot also demonstrated prin- ciple of ice blocks production using a solar-driven adsorption chiller. Then he developed the first parabolic solar collector and made a few interesting public demonstrations of his inventions in Paris. Even Emperor Napolen III was im- pressed by Mouchot , s device presentation. His scientific achievements were amused. We can call him the pioneer in the field of solar energy. "One must not believe, despite the silence of modern writings, that the idea of using solar heat for me- chanical operations is recent. On the contrary, one must recognize that this idea is very ancient and its slow development across the centuries it has given birth to various curious devices." - Augustin Bernard Mouchot, at the Universal Ex position, Paris, France (1878). Augustin Mouchot predicted a need for solar en- ergy. "Eventually industry will no longer find in Europe the resources to satisfy its prodigious expan- sion... Coal will undoubtedly be used up. What will industry do then?" - Augustin Bernard Mouchot, after demonstrat- ing an early industrial application of solar thermal en- ergy (1880). Augustin Bernard Mouchot was born in France on 7 April 1825. Town where he was born Semur- en-Auxois is located within Burgund’s region. At first he was a teacher at the primary schools of Morvan (1845–1849) and then taught at Dijon. In 1852 he attained a degree in Mathematics and a Bachelor of Physical Sciences in 1853. Later Mou- chot was a mathematics teacher in secondary schools of Alençon in years (1853–1862), Rennes and Lycée de Tours in years (1864–1871). In this period of time the French teacher – Augustin Mouchot started to undertake research on solar energy. The idea of finding new alterna- tive energy sources overwhelmed him. In 1860 he began exploring solar cooking, based on the work of Horace-Bénédict de Saussure and Claude Pouil- let. Horace de Saussure was a French - Swiss scien- tist and started his work of solar cooking in 1767 building a miniature greenhouse ,in which he placed a pieces of fruits. This new technology called solar cooking. Horace continued his exper- iments with other materials as insulators an tried cooking at different altitudes. Claude Servais Ma- thias Pouille was a French physicist.. Between 1837 and 1838, independently of John Frederick Wil- liam Herschel (1792-1871), he made the first quantitative measurements of the heat emitted by the Sun. In 1866 Augustine Mouchot had developed the first parabolic solar collector. He designed a new collector, which concentrated the rays of sunlight from all sides of absorber. He experimented with a water-filed container enclosed in glass, which was exposed to the heat of sun until the water boiled. The steam that was produced provided power for a small steam engine. That was a great achievement. This device was presented in Paris in August 1866 to the Emperor Napoleon III, and the inventor was founded for a more ambitious phase of building. 2 Biography: Augustin Bernard Mouchot Storytelling Teaching Model: wiki.science-stories.org It is worth to mention, that in this time a very high speed progress of industrialization in France and other countries was noticed. Many factories used steam engines. It was necessary to have sources of fuel for steam engines. In France a big problem with coal appeared. The source of this fuel was almost exhausted. Moreover, France had to import a coal from England. Coal was expen- sive. French government promised to support fi- nancially all researches, which could create possi- bility to be independent on coal imported from England. That was a good moment to find alterna- tive energy to develop and use the solar energy. Thus, the consecutive years gave Mouchot possi- bility to improve his inventions of solar systems. Over the next few years, Mouchot built lager and lager machines One of his most successful inventions was presented at the Great Exhibition of the most modern technologies from around the world in 1867. Many attendees were amazed at this invention. A huge crowd gathered at Mou- chot’s “solar engine” device. It had a huge light – capturing apparatus that could generate enough steam to power a small engine. In his book “The Power of Light: The Epic story of Man’s Quest to Harness the Sun Frank Kryza said on the device: “When Mouchot put it on the display, the reaction was one of stupefied amazement – a motor that ran without fuel, on nothing more than sunbeams! It struck observers as bizarre – even magical.” Mouhout won a first place medal at this exhibi- tion and could continue his work on the devel- opments. In 1869 he poured himself into writing the first book ever devoted to solar energy: La Chaleur so- laire et ses Applications industrielles and at the same time he displayed in Paris the largest solar steam engine he had yet built. But Paris was at that time under siege during the Franco-Prussian War in 1871, however, the monster engine was not found after the siege ended. In September 1871, Mouchot received financial assistance from the General Council of Indre -et- Loire to install an experimental solar generator at the Tours library. In December 1875 he presented to the Academy of Sciences a device, which he claimed would provide a steam flow of 140 liters per minute in optimal sunshine. He got the per- mission from the ministry to leave his teaching position in order to develop work on an engine for the Universal Exhibition of 1878. He had im- portant mission to execute solar engines in French Algeria. He got a grant for the purchase of mate- rials and execution of solar engines and was rec- ommended to the Governor of Algeria. Augustin Mouchot from 1860 to 1878 built dif- ferent mirrors and use them to cooking food, boiling water, pumping water and even producing brandy. At first Mouchot solar device was able to bring three liters of water to boil in one and a half hours. Muochot invented the conical mirror and implemented in cooker in 1870’s. Parabolic mirror concentrate the reflected rays of sun light to a point and cone concentrate light to a line. Mou- chot found out that cone mirror can be quite enough good to boil water for tea or produce steam for engines. Construction of cooker with the conical mirrors was much more easy. First solar pump was build in 1861 and in 1874 Muochot used a solar energy for pumping water in Algeria. Mouchot’s solar devices were used by the French soldiers in North Africa. In this way they were preparing meals without a smoke. A few solar system were build and used to power stem engines. On September 1878 at the World Exhibition in Paris Mouchot presented the biggest one. The mirror concentrating solar ener- gy had diameter of five meters. All device could produced an ice blocks, using solar energy and machine of Edmund Carre*. This big mirror has one disadvantage. It was made of silver and oxi- dized and had to be often clean. Muochot was awarded a gold medal for presentation of this ex- periment. Furthermore, in 1880, Mouchot’s assistant Abel Pifre –a French engineer presented a solar- powered printing press. Sunlight from parabolic mirror heated up water in small boiler and pro- duced steam for steam engine, which drove print- ing machine. Abel Pifre was able to print 500 cop- ies per hour of his newspaper “Soleil-Journal”. However, The political and economical situa- tions in France have changed. The economy in France was improving. The Cobden-Chevalier Treaty** between France and the United Kingdom Biography: Augustin Bernard Mouchot 3 Storytelling Teaching Model: wiki.science-stories.org © 2012, S@TM Research Group caused that coal became cheaper. It was a very im- portant commitment for France in time when sources of coal were exhausted. Later French min- ers have found new coal deposits in Eastern France. Due to this fact the government was not more interested in supporting financially researches on alternative energy. Additionally, French govern- ment assessed that solar energy was not enough economical. Mouchot studies become less im- portant as before. He hasn’t got more financial support. His activity concerned with the investiga- tions and implementations of solar energy in prac- tice stopped. Mouchot went back to the teaching profession. Imagination and inventions of Mouchot were appreciated by the Institute of France. He received twice prizes in 1891 and in 1892 and he was named Lauréat de l'Institut by the Institut de France. Augustin Bernard Mouchot died in Paris.1912. * The first absorption machine was developed by Edmond Carre in 1850, using water and sulfuric acid. ** The Cobden–Chevalier Treaty was a Free Trade treaty signed between the United Kingdom and France, on January 23,1860. It was named after the main British and French originators of the treaty, Richard Cobden Member of Parliament and Michel Chevalier. References: http://en.wikipedia.org/wiki/Augustin_Mouchot Gordon, Jeffrey, Solar energy, International Solar Energy So- ciety, ISBN 9781902916231 http://en.vionto.com/show/me/Augustin+Mouchot http://en.wikipedia.org/wiki/Solar_thermal_energy Biography: Augustin Bernard Mouchot was edited by Ste- phen Klassen and Cathrine Froese Klassen and is based, in part on Historical Backgrounds: Energy and Solar cooker according to Augustin Mouchot written by Peter Heering. Biography: Augustin Bernard Mouchot was written by Emi- lia Dobrowolska with the support of the European Commis- sion (project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and Polish Association of Science Teachers, Poland. This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein. EN_Guidelines_Mouchot.pdf Suggestions to Teachers (Mouchot and the solar cooker) 1 Storytelling Teaching Model: http://science-story-telling.eu Suggestions to Teachers (Mouchot and the solar cooker) Expected results After the lesson, the students are expected to: 1. Describe the device, which was constructed by Mouchot, in order to meet his personal everyday needs. 2. Construct an experimental device, which is a simulation of the Mouchot’s solar oven, in order to experiment with it and interpret its function. 3. Locate the principles of operation : a) Mouchot’s solar oven and solar steam engine b) the solar ovens and solar steam engines of the current technology. 4. Write the prevailing reasons for Mouchot’s scientific research which call for the exploitation of solar energy of this time and today. 5. Construct solar ovens and to organize an exhibition with their constructions. 6. Demonstrate that Mouchot's research provided a solution to a social problem at his time and generally, the social needs indicate and sometimes define the field of the scientific inquiry. 7. Describe the device, which was constructed by Mouchot and won the first award in the exhibition of Paris, and identify its innovation, based on the narration. 8. State the reasons indicating the necessity of the exploitation both of the solar energy and the renewable resources nowadays. 9. Distinguish the conventional from the renewable resources of energy. 10. Investigate the science characteristics and the ways science develops in the Mouchot’s story as well as the activities of the lesson, according to the McComas’ list. 11. Demonstrate the relation between the science, the society, the economy and generally the politics. 12. Demonstrate: a) that science progresses through research, but its progress could decelerate or stop by various obstacles b) the diachronism between the social demands and the correlating scientific questions. About the activities of students The proposed students' activities are indicative and they aim at the accomplishment of the above expected outcomes. Moreover, the teacher may choose some of them for the teaching process in relation to its aims, the needs of students and the available time. Finally, she/he can create her/his own activities. About the emergence of the characteristics of science in the narration, these characteristics are quoted in the website, comprehensively (in classification of the stories by NOS). 2 Suggestions to Teachers (Mouchot and the solar cooker) Storytelling Teaching Model: http://science-story-telling.eu About the locating of the characteristics of Nature of Science in the proposed activities, indicatively, we can quote the following: A) In activity 1 the cases 1, 2 and 5 concern the characteristic of Nature of Science: “There are historical, cultural, and social influences on science”, but case 4 concerns the characteristic: “Science is a highly creative endeavor”. B) The activity 2 concerns the characteristics of Nature of Science: a) “Science and technology impact each other, but they are not the same” and b) “Scientific knowledge is tentative but durable”. C) The activity 3 concerns the characteristic of Nature of Science: “Science and technology impact each other, but they are not the same”. D)The activity 4, case 2 concerns the characteristic of Nature of Science: “Scientific knowledge is tentative but durable”. E) The activity 5 concerns the characteristics which are quoted in the previous activities: 2, 3, 4 and the next activity. G) The activity 6 concerns mainly the characteristics: a)“Science and technology impact each other, but they are not the same”, b) “Science demands and relies on empirical evidence” and c) “Science is a highly creative endeavor”. Suggestions to Teachers (Mouchot and the solar cooker) were written by Aikaterini Rizaki and Panagiotis Kokkotas with the support by the European Commission (Project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and the NKUA of Greece. This publication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained there in. EN_LA_Mouchot.pdf Student’s Learning Activities (Mouchot and solar cooker) 1 Storytelling Teaching Model: http://science-story-telling.eu Student’s Learning Activities (Mouchot and solar cooker) Activity 1 You will watch a video with narration or listen to a story from your teacher about Augustin Mouchot and his work on the development of the solar ovens and the solar steam engines. Please write down the main points of the story, in your view, and discuss about them in your group. (Indicative important points of the story: the description of Mouchot’s device for the exploitation of solar energy in order to solve his everyday needs for warm water, the description of Mouchot’s solar steam engine for which he won the first prize in the 1878 Paris exhibition, the reasons that the French Government firstly started financing and then stopped financing the research of Mouchot, the way of Mouchot’s life, his end , ...) ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… …………………………………………………………………………………..…………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………. 1. Based on the story you heard from the narrator please record two reasons that led Mouchot to search for devices utilizing solar energy. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………… 2. Please discuss in your group the reasons for which the French Government firstly started financing and then stopped financing the research of Mouchot. Please write one reason for each case. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… 2 Student’s Learning Activities (Mouchot and solar cooker) Storytelling Teaching Model: http://science-story-telling.eu ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………... 3.Please describe the device was built from Mouchot in order to solve his everyday needs for warm water. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………..……………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………… 4. Please describe the device built from Mouchot for which he won the first prize in the 1878 Paris exhibition. You have at your disposal the image from the following website from which you can get more information: http://landartgenerator.org/blagi/archives/2004 ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………..……………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… http://landartgenerator.org/blagi/archives/2004 Student’s Learning Activities (Mouchot and solar cooker) 3 Storytelling Teaching Model: http://science-story-telling.eu ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………… 5. Pease discuss in your group about the advancement of science and the social, cultural and economic circumstances that prevail at that time. Please write down the view of your group. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… Activity 2 In this activity you are invited to experiment on the absorption of solar radiation. Let us try, to implement an experiment similar to that Mouchot implemented in his research. Because we are indoors, instead of solar radiation we will use the radiation of an electric bulb. Materials: • A heat sensor with a glass cover and a digital thermometer or, if there is not any, we can use a metallic thermometer. • A radiation collector in the form of concave mirror made of aluminum. •An electric bulb. Experimental procedure: a) Please place the tip of the thermometer at the focus of the concave mirror. b) Place the electric bulb at 20 cm distance from the tip of the thermometer. c) Set the electric bulb to radiate for 10 minutes. d) Record temperature changes in Table 1. Table 1 Take the temperature every 2 minutes 4 Student’s Learning Activities (Mouchot and solar cooker) Storytelling Teaching Model: http://science-story-telling.eu Time (min) Temperature (in ° C) 0 2 4 6 8 10 1.Please explain: a. the raise of the temperature at the focal point. b. the placement of the tip of the thermometer at the focal point of the concave mirror. …………………………………………………………………………………………………………………………………..…………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………..…………………..………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………………………………………………………….. 2. Make a graph: temperature against time and from that find the raise of the temperature for the time interval 6th min 8th min. 3. Based on the images below (these are solar ovens of modern technology) Student’s Learning Activities (Mouchot and solar cooker) 5 Storytelling Teaching Model: http://science-story-telling.eu describe a solar oven modern technology: ......................................................................................................................................................................................................... ......................................................................................................................................................................................................... ......................................................................................................................................................................................................... ......................................................................................................................................................................................................... ......................................................................................................................................................................................................... .......................................................................... ......................................................................................................................................................................................................... .............................................................................................................................................................. ......................................................................................................................................................................................................... .............................................................................................................................................................. ......................................................................................................................................................................................................... .............................................................................................................................................................. ......................................................................................................................................................................................................... .............................................................................................................................................................. 4. Please discuss in your group the principles of operation of a solar oven of modern technology and write the missing words below: a) ............................ light b)the absorption of light in ............... body c) the effect of ....................... 6 Student’s Learning Activities (Mouchot and solar cooker) Storytelling Teaching Model: http://science-story-telling.eu 5. In the diagram below draw the angle of incidence and the angle of reflection. This will enable you to explain the principles of operation of the solar oven. Activity 3 The experimentations so far will help you understand the operation of Mouchot’s steam engine. 1. Please watch the video in the following link for solar steam engine: http://www.youtube.com/watch?v=jTvAL7ty53M&feature=player_embedded#at=23 Based on your observations please compare the operating principles of solar steam engine with those of solar ovens. Write the further principles of function for the solar ovens and the solar steam engines. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………. Activity 4 http://www.youtube.com/watch?v=jTvAL7ty53M&feature=player_embedded#at=23 Student’s Learning Activities (Mouchot and solar cooker) 7 Storytelling Teaching Model: http://science-story-telling.eu 1. Please discuss in your group the difference between a renewable source of energy and a conventional one and indicate two sources of energy from each category. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… 2.Please argue in your group about the reasons for which the future of our society depends on the renewable energy sources and not on the conventional ones. Please write a text of 1000 characters to support this statement referring to three such reasons. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………… Activity 5 Using the list of ideas that describe the characteristics of science and the ways it develops, try to locate and write these ideas in the story you heard and the activities of lesson. These ideas that scientists call Nature of Science (Nature Of Science-NOS- ) are: Characteristics of Nature of Science (NOS) 1. Science demands and relies on empirical evidence 2. Knowledge production in science includes many common features and shared habits of mind. 3. Scientific knowledge is tentative but durable. 8 Student’s Learning Activities (Mouchot and solar cooker) Storytelling Teaching Model: http://science-story-telling.eu 4. Laws and theories are related but distinct kinds of scientific knowledge. 5. Science is a highly creative endeavor. 6. Science has a subjective element. 7. There are historical, cultural, and social influences on science. 8. Science and technology impact each other, but they are not the same. 9. Science and its methods cannot answer all questions. Scientists argue that in order to learn science one must first understand what exactly science is. Because it is difficult to define science, scientists give a list of its characteristics. ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………..……………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………… ……………………………………………… Activity 6 Constructing solar ovens using the project approach. A) The Students of the class form groups, following criteria on which they have agreed upon in advance. In order to construct solar ovens using different patterns and simple materials, they collect information from different sources, such as, photos, texts, newspapers, websites, etc. The solar ovens will be used for their families’ summer camping holidays. B) They look for ways to compare measure of efficiency of their constructions (e.g. use thermometers to measure the temperature inside the ovens, to measure the time needed to heat of a certain quantity of water to a certain temperature, melting a block of ice, etc.). C) A time period of 5-6 weeks is necessary for the implementation of the project. D) Students argue about the differences of efficiency of their solar ovens. An organization of an exhibition with the solar ovens will be a very good motivation event. Student’s Learning Activities (Mouchot and solar cooker) 9 Storytelling Teaching Model: http://science-story-telling.eu Student’s Learning Activities (Mouchot and solar cooker) were written by Aikaterini Rizaki, Panagiotis Kokkotas and Ioannis Vlachos with the support by the European Commission (Project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and the NKUA of Greece. This publication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained there in. Historical Ressources).pdf Historical Resources • Primary literature Mouchot, Augustin Bernard: La Chaleur solaire et ses applications industrielles 1869, available online: http://archive.org/details/lachaleursolair00moucgoog. Mouchot, Augustin: Die Sonnenwärme und ihre industriellen Anwendungen, Oberbözberg, Schweiz 1987. Pope, Charles Henry: Solar Heat, its Practical Applications, 1903, online available: http://archive.org/details/solarheatitspra00popegoog. (enthält eine Übersetzung des Inhaltsverzeichnisses von Mouchots Hauptwerk : Le Chaleur [...]) Simonin, Louis Laurent: Industrial Applications of Solar Heat, [via wikisource], in: Popular Science Monthly 9, Ausgabe September (1876), S. 550–560, available online: http://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_9/September.... • Secondary literature Bradford, Travis: Solar Revolution: The Economic Transformation of the Global Energy Industry, Cambridge, Mass. u.a. 2006. Kryza, Frank T.: The Power of Light: The Epic Story of One Man’s Quest to Harness the Sun, New York, N.Y 2003. links.pdf http://www.youtube.com/watch?v=sKUDAS884VQ& Story_Mouchot_ENG.pdf The Soul of Solar Energy: Augustin Mouchot 1 Storytelling Teaching Model: http://science-story-telling.eu The Soul of Solar Energy: Augustin Mouchot It was a typical, cold January morning in Alençon, France. The year was 1860. High school mathemat- ics teacher, Augustin Mouchot shivered as he reluctantly rolled out of bed. The thought of having to stoke the stove and heat the water for his morning washing routine did not thrill him. Besides, he needed to conserve the coal, which was growing scarce in his homeland and becoming expensive these days. As Augustin arose in the chill of the dawn, his thoughts drifted to what he had just been reading about the energy of the sun. Physicist Claude Pouillet had written that every square meter of the Earth’s surface receives about 10 Calories of energy every minute. Augustin chuckled, “Not a very use- ful fact on a cloudy day like today!” Then, a flash of inspiration crossed his mind: “It’s not cloudy every day. Wouldn’t it be possible to heat enough water with the sun’s light and spare the fire that is only meant to heat the house?” While he made the last preparations to teach his geometry class, he could not get his mind off the energy issue. The thought kept coming back to him, “The issue of energy is bigger than the needs of my household—I should try to do something about it.” Over the next few months, Augustin immersed himself in his new project of building a solar en- ergy collector despite having to teach his regular classes. He reviewed what he had already learned about harnessing the energy of the sun. Reasoning that copper is a good conductor of heat and a black surface is a good absorber of heat, he would have to contain the water in a copper vessel that was painted black. The water would then obtain its heat from the copper. To prevent the heat from escaping out the back, he thought it better to mount the unit on a bad conductor of heat, and to prevent the heat from escaping out the front, he would cover it with glass to trap the heat that was absorbed inside. “What a great idea!” he thought. “But, in order to get more heat, I would have to make a bigger absorber—not very practical…. On the other hand, what if I put a mirror on the out- side to reflect more of the sun’s rays onto the ab- sorber? That way I could make the device smaller.” Soon, Augustin had completed the construc- tion of his first solar water heater, which was ca- pable of holding three litres of water. Lucky for him, it happened to be a cloudless day! Excitedly, he placed the boiler and mirror in the direct sunlight. To his amazement, the water, which he had initially measured to be 15 degrees, boiled in just an hour and a half. From then on—on sunny days—Augustin saved himself the bother and the expense of coal-heated water when he bathed. With further improvements to the solar heat- ers, Augustin was able to bring water to a boil more quickly. He began to ponder new and bigger possibilities. “Perhaps, I could design solar steam generators to power machines, like the steam en- gines used in industry,” he thought. Coal was the main fuel for industry, but France was already ex- periencing a shortage of this expensive resource. “When the supply of coal eventually runs out,” he reasoned, “then using the energy of the sun might be our only available alternative.” Augustin thought that his idea of a solar-powered engine could contribute to the well-being and progress of the entire nation. Harnessing the sun’s energy became a fascina- tion and all-consuming preoccupation for Au- gustin. “We need to heat so many things in every- day life—water, home, food…. Why, of course, food!” So, the mathematics teacher turned cook prepared a delicious stew for dinner and cooked it in his solar heater. The solar heater had become a solar cooker. Over the next several years, Augustin contin- ued to work on his solar energy idea, employing his natural creativity and his university training in physics and mathematics. He especially wanted to develop a solar engine that could drive all kinds of mechanical devices used in industry and agricul- ture. By 1866, he was ready to launch his idea in the public domain. Political support would be ad- vantageous at this strategic moment. His connec- tion with Jean-Baptiste Verchère de Reffye, Ord- nance Officer of the Imperial Workshop at Meu- don, who had influence with the Emperor, proved 2 The Soul of Solar Energy: Augustin Mouchot Storytelling Teaching Model: http://science-story-telling.eu useful. De Reffye persuaded Napoleon III to at- tend a demonstration of Augustin’s new solar en- gine. The Emperor was so impressed with the in- vention that he immediately granted Augustin the full assistance of the Imperial Workshop. With this level of technical assistance, the inventor could forge ahead. By the next year, Augustin had perfected a so- lar engine capable of driving an Archimedean screw that could be used to pump water for irriga- tion. In its design, he found that the main consid- erations were the geometrical arrangement of the heat absorber and the mirror. The best shape for the mirror was an open-ended cone, with the cu- rious mathematical name of “frustocone,” that focused the sun’s rays along a line on its axis where a narrow cylindrical heat absorber, which contained the steam generator, was located. The device was installed in Paris, and at that occasion, Augustin remarked, “The problem of the steam- driven solar machine has been completely solved. We should judge from this result that the engine would best be used in tropical regions, where we should go to test the device in practical situations.” A logical testing location for Augustin was Al- geria, a French colony in the tropics, conquered in 1830. Of course, he still had to continue in his teaching position, which entailed restrictions of time and finances. Augustin quickly realized that in order to be able to reach his goals, he would need to obtain major government funding and leave from his teaching duties. Just when he was poised to take his final, strategic steps to obtain funding, war broke out between France and Ger- many. It was 1870. The war was fast and furious, and, by the next year, France had been defeated, Napoleon III had been sent into exile, and a new government was formed—the French Third Re- public. Many of the arrangements that Augustin had had in place vanished, the notable solar ma- chine that he had set up in Paris was nowhere to be found, and the technical support from the Im- perial Workshop was suspended. It was a monu- mental setback for Augustin, but he was not dis- couraged. From 1871, then, Augustin set out to lay the groundwork for his solar dreams in other ways: by writing about his work and applying for patents. Astonishingly, while still being a full-time mathe- matics teacher, he managed to complete a 233- page volume, which he entitled Solar Energy and its Industrial Applications. The book advertised his dream of, in his words, “finding a convenient way to collect and use sunlight directly for the benefit of agriculture and industry in the hottest regions of the world.” In order to establish the importance of his ideas, he was able to register three patents for his designs, and by 1876, he had achieved suf- ficient fame with his work that the government awarded him a silver medal. Most importantly, though, that year Augustin was granted leave with pay from his teaching position by the government so that he could devote all of his time to his work on solar energy in the tropics. His dream would come true at last! In the very next year, Augustin Mouchot set sail for Algeria—financed by a huge government grant of 10,000 francs. In Algeria, he invented and tested many ver- sions of his solar energy devices for many different useful purposes. Perfecting his solar cooker proved strategic for the military, which could bet- ter conceal their positions as they prepared their food in smoke-free heaters. His report on his in- ventions to the government impressed the General Council so much that Augustin was granted 5,000 francs to design and build the largest solar collec- tor ever to be built. It was to be exhibited at the Paris World Fair of 1878. For the difficult task of building the giant solar collector, Augustin placed a talented, young engi- neer, Abel Pifre, in charge. Although the World Fair took place between May 1 and October 31, the mirror was completed only by the second of September. At that time, the collector was able to bring 70 litres of water to a boil in half an hour and generate steam pressure of six atmospheres. Augustin and Abel used the steam generator to drive an ice-making machine, using the hot sun’s rays to produce a block of ice. The people at the fair marvelled at the phenomenon—producing ice from heat! The jury of the Fair was so impressed that it awarded Augustin the gold medal in his category, and the Ministry of Agriculture and Trade, not to be outdone, named him Knight of the Legion of Honour. The Soul of Solar Energy: Augustin Mouchot 3 Storytelling Teaching Model: http://science-story-telling.eu Not wanting to waste the opportunity provided by the honours, Augustin applied for government funding for a new mission to Algeria immediately after the World Fair. Inexplicably, and to his dis- may, the government granted him only 5,000 francs. His disappointment at the inadequate sup- port, however, did not keep him from pursuing his mission, and he departed for Algeria, once again, to perform new experiments. Ever optimistic, he, once more, returned to France to apply for a large amount of new fund- ing. This time, his request was denied outright. What a letdown for Augustin! The government, having commissioned a study on the economic viability of solar energy, had concluded that there was no justification for further research. National and global events were fast eroding Augustin’s aspirations. More coal deposits had been discov- ered in eastern France, making coal more abun- dant and less expensive, and lessening the pressure to develop other energy sources. In the USA, oil, having been discovered in 1859, was already being harnessed as a fuel to supply energy needs. Ironi- cally, the 1878 World Fair, where Augustin had gained his international stature, marked the un- veiling of the internal combustion engine. This proved to be the final undoing of Augustin’s fad- ing solar-energy dream. Could the situation get any worse? It did. Au- gustin’s leave from teaching was to expire in the following year, but circumstances prevented him even from resuming his position, as a serious bac- terial infection, which he had contracted in Alge- ria, had left him deaf. A small consolation was that his disability allowed him to apply for a pension, which was fortunate, as he had already reached the age of 55 years. Deteriorating eyesight and meagre finances plagued his retirement. Yet, he was able to com- plete and publish an important book on geometry in 1892, for which he received a prize from the Science Academy. Thereafter, he receded from the public eye. In 1907, a member of the Science Academy discovered that Augustin was living in deep misery, and the Academy generously granted him an additional pension of 1,200 francs. One day, the lonely Augustin received a visitor. It was the military doctor Félix Pasteur from Alge- ria. The doctor told him about the use of solar wa- ter heaters in hospitals and military barracks there and expressed appreciation to him for this valu- able contribution. It was one of the last satisfying joys Augustin was to experience. On October 4, 1912, eighty-seven-year-old Augustin Mouchot, no longer capable of even picking up his pension from the post box, died penniless and alone. How the coincidental interplay of economics, politics, and history can crush humanitarian ideals and decimate noble dreams! References Kryza, F. (2003). The Power of Light: The Epic Story of Man’s Quest to Harness the Sun. New York: McGraw-Hill. Larousse Encyclopedia. Augustin-Bernard Mouchot. [http://www.larousse.fr/encyclopedie/article/Larousseen_- _Article/11013613#] Quinnez, B. (2011). Augustin-Bernard Mouchot (1825-1912), un missionnaire de l’énergie solaire. Assemblée Générale de Côte-d'Or de l'AMOPA, 30 mars 2011. [http://www.amopa21.fr/2011%20conference%20.htm] The Soul of Solar Energy: Augustin Mouchot was edited by Cathrine Froese Klassen with the support the European Commission (project 518094-LLP-1-2011-1-GR- COMENIUS-CMP) and The University of Winnipeg, Canada, and is based, in part, on Historical Background: The Energy Concept and Historical Background: Solar cooker according to Augustin Mouchot written by Peter Heering, and Biography: Augustin Bernard Mouchot writ- ten by Tadeusz Kubiak and Jozefina Turlo. The Soul of Solar Energy: Augustin Mouchot was written by Stephen Klassen with the support the European Commission (project 518094-LLP-1-2011-1-GR- COMENIUS-CMP) and The University of Winnipeg, Canada. This publication reflects the views only of the au- thor, and the Commission cannot be held responsible for any use which may be made of the information contained therein. 4 The Soul of Solar Energy: Augustin Mouchot Storytelling Teaching Model: http://science-story-telling.eu The solar cooker according to Mouchot.pdf Historical Background: The solar cooker according to Augustin Mouchot 1 Storytelling Teaching Model: http://science-story-telling.eu Historical background: The solar cooker according to Augustin Mouchot In mid-nineteenth century, industrialization progressed at high speed. One of the side effects was the ne- cessity to have fuel for the seam engines that were the central power source in the factories. To France, this started to pose a major problem, as the coal deposits turned out to be limited and were almost ex- hausted. This was even more a problem as the potential imports could only come from England—the tra- ditional (economic) rival to France. Consequently, the French government promised financial support to any researcher who proposed promising concepts of how to avoid a dependency of France from English coal. This was the moment when the French secon- dary school teacher Augustin Mouchot entered the stage. Mouchot combined two devices that had been known previously: A blackened hollow cyl- inder containing water—a similar device had been used by the end of the eighteenth century by Horace Benedict de Saussure for making experi- ments on heat radiation. This was combined with a hollow mirror that was used to focus solar radia- tion on the cylinder. Already in 1861, Mouchot was able to produce steam with his device. In the following years, he intended to improve his set-up to make it more useful for technical purposes. The attempts were financially supported by the French government. Two outcomes can be named as direct results: On the one hand, Mouchot was able to develop solar cooking devices—items that were used in particular by the French army in their North Afri- can colonies. These devices enabled the soldiers to prepare hot meals without producing smoke, a detail relevant from a military perspective. These cookers were used until the 20th century. The other result of Mouchot’s attempts was a steam engine that was operated with steam pro- duced by his solar apparatus. Mouchot devised several of the engines; the largest was shown at the world exhibition in Paris in 1878. The conical mir- ror had a diameter of some five meters, and the engine could be used as a printing device and was also able to produce ice. Mouchot was awarded a gold medal for this machine. Yet, by this time, things had changed once again. A major problem of Mouchot’s ma- chine remained the mirror which was made with a silver coating—this tended to oxidize, thus reduc- ing the efficiency of the machine and requiring a constant cleaning of the mirror. However, another development turned out to be far more problem- atic for Mouchot: Miners had found new coal de- posits in Eastern France; consequently, the neces- sity for finding an alternative source of energy for the steam engine did not exist any longer. More- over, in a report, Mouchot’s machine was labeled as economically inefficient. As a result, the French government ceased to support Mouchot’s research financially. This brought his work to an end. References Kryza, F. (2003). The Power of Light: The Epic Story of Man’s Quest to Harness the Sun. New York: McGraw-Hill. Quinnez, B. (2011). Augustin-Bernard Mouchot (1825-1912), un missionnaire de l’énergie solaire. Assemblée Générale de Côte-d'Or de l'AMOPA, 30 mars 2011. [http://www.amopa21.fr/2011%20conference%20.htm]. Historical Background: The solar cooker according to Au- gustin Mouchot was written by Peter Heering with the support of the European Commission (project 518094-LLP- 1-2011-1-GR-COMENIUS-CMP) and the University of Flensburg, Germany. This publication reflects only the views of the author, and the Commission cannot be held responsi- ble for any use which may be made of the information con- tained therein.

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• Mouchot and the solar cooker

by the next year, France had been defeated, Napoleon III had been sent into exile, and a new government was formed—the French Third Re- public. Many of the arrangements that Augustin had had in place

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• Mouchot and the solar cooker

. Fortunately, unlike most other children his age, Benjamin was sent to grammar school at age eight. By age 13, having ac- quired a mastery of advanced algebra, geometry, as- tronomy, and even higher mathematics, he left school and was sent to a nearby town to learn a trade, as an apprentice. He tried many different jobs, but none of them held his interest. He spent most

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• Rumford and nutrition
• Rumford and calorics

. Fortunately, unlike most other children his age, Benjamin was sent to grammar school at age eight. By age 13, having ac- quired a mastery of advanced algebra, geometry, as- tronomy, and even higher mathematics, he left school and was sent to a nearby town to learn a trade, as an apprentice. He tried many different jobs, but none of them held his interest. He spent most

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• Rumford and calorics

– Peter lifted his arm and pointed his thumb at the back to pre- sent what he thought of. ‘They are really amazing’ – said Henry with the cutest voice he could come up with. He added also his cute,

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• Lichtenberg and the electrophorus

– Peter lifted his arm and pointed his thumb at the back to pre- sent what he thought of. ‘They are really amazing’ – said Henry with the cutest voice he could come up with. He added also his cute,

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• Lichtenberg and the electrophorus

the telegram in his hand. Finally, Irene was back into the pre- sent, smiled at the man and said: “Do you want me to open that telegram?” The man looked somewhat puzzled and responded: “No, Mad- ame,

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• Joliot-Curie and artificial radioactivity

Biography_Joliot-Curie_ENG.pdf Biography: Irène Joliot-Curie 1 Storytelling Teaching Model: wiki.science-stories.org © 2012, S@TM Research Group Biography: Irene Joliot - Curie (1897-1956) Irène Joliot-Curie - older daughter of Marie Skłodowska - Curie. She gained the knowledge about the radioactivity under her mother’s wing, and she assisted her in the Radium Institute in the university in Paris from 1918. In 1925 she defended the doctoral thesis on alpha particles emitted by Polonium, and in 1926 she married her mother’s assistant, Frederic Joliot, who was 3 years younger than Irene. They had two children: the daughter, Helene, and the son, Pierre. The Joliots did not discover the neutron and the positron as the first people, because they wrongly interpreted their measurements. However, in 1935 they were honoured with the Nobel Prize in chemistry for their discovery of the induced, artificial radioactivity. Irene Curie, the daughter of famous and outstanding scientists, Pierre Curie and Marie Skłodowska-Curie was born on 12th September 1897 in Paris. From early years, she showed signs of the outstanding capabilities in the fields of maths and physics. She was taught by the professors of Sorbonne in quite not typical way: she spent one day in the maths laboratory, one in chemistry laboratory and one at history teacher’s house, and she was taught physics by her mother. In the following years, her knowledge about maths and chemistry let her teach her peers from the college in Sevigne. The girl’s character, her world-view and love to science were shaped by her mother. The father, Pierre, had also the huge impact on Irene. Unfortunately, he died tragically on 19th April 1906 while he was trying to cross the Dauphine street in Paris. Doctor Curie (Pierre’s father) helped in bringing-up his granddaughters, Irene and Eve, by replacing their often absent mother and dead father. In 1914, after finishing the science-maths high school, Irene Curie started her studies at the faculty of the Sciences at the University of Paris. In the middle of 1916, she interrupted her studies, because she enrolled in the radiology service of the French Red Cross, organised by her mother. Irene assisted her mother in the front of the First World War as the radiology nurse in ambulances, helping the injured people. After the war, in 1918, she restarted her studies. Shortly after that, she agreed on the post of the laboratory technician in the Radium Institute in Paris, and later she became the assistant, and as a result, the co-worker of her mother. Thanks to that job, she gained the valuable experience. In 1921, she already had the bachelor’s degree in physics and maths, and she finished her research in which she indicated the atomic mass of chlorine, gained from different materials. She was also interested in radioactivity. She worked out the equipment used to measure the radioactivity in the substances used in farming, and in 1924, together with Catherine Chamie, she published the work on radioactive decay constant of radon. While assisting her mother, and even replacing her in working in the Institute, Irene took up the research on the alpha particles emitted by the polonium – the element discovered by Marie Skłodowska -Curie in 1898. The results of that research she included in her doctoral thesis, which she submitted in 1925. The dissertation on the properties of radiation was published in the magazine Annales de Physique. Young Irene set the amount of alpha particles emitted by polonium samples with the specified activity. She deeply investigated the range, energy, and the ionisation, which is caused by the alpha particle along its track. She conducted her experiments using the Wilson chamber. Basing on the ionisation method she determined (together with František Běhounek) Bragg curve, representing the average density of ionization caused by the alpha particle depending on the way in the absorbent (air or different gases). In the following years, Irene still referred in her works to the number of ions appearing in the air under the effect of the element radium C radioactivity. She conducted this research in the years 1927-1929, together with Frederic Joliot, whom she met in the Radium Institute in Paris 2 Biography: Irène Joliot-Curie Storytelling Teaching Model: wiki.science-stories.org and married in 1926. They took the name “Joliot- Curie”. Frédéric Joliot was the physics engineer. He graduated from Engineering School in Paris, where one of the professors was Paul Langevin, a friend of Curie's family. With his recommendation, Joliot was given the job in the Radium Institute. After the marriage, both spouses started their research. Their co-operation was easier thanks to their common interests and their infinite aiming at gaining knowledge. The resemblance between Irene and Frederic was similar to the one that connected Pierre Curie and Marie Skłodowska. Frédéric, like Pierre, was more a physicist, while Irene was more interested in the chemistry, like her mother. The Joliot-Curie co-operation resulted in genius scientific discoveries, like it was previously in case of Irene’s parents. Unfortunately, in winning fame, they were forestalled by others twice, because they wrongly interpreted the results of their measurements. In the first discovery, they were forestalled by James Chadwick, who in 1932 finally and undeniably proved the existence of neutron in the reaction: nCHeBe 1 0 12 6 4 2 9 4 (1) For this discovery in 1935 he received the Nobel Prize in physics. But in the summer of the same year, Carl David Anderson proved the existence of positron, using the Wilson chamber. Between 1932 and 1934 the Joliot – Curies jointly published a number of important papers on the effect of alpha particles on various elements. In January 1934, Frédéric and Irene Joliot-Curie conducted the nuclear transformation reactions in which they discovered the artificial radioactive elements, eg: eeSiPnPHeAl 0 1 30 14 30 15 1 0 30 15 4 2 27 13 (2) eeCNnNHeB 0 1 13 6 13 7 1 0 13 7 4 2 10 5 (3) eeAlSinSiHeMg 0 1 27 13 27 14 1 0 27 14 4 2 24 12 (4) On that day Frédéric said: “we were late with neutron, we were late with positron, now we are on time”. They proved that the element can be forced to release some part of the energy in the process of radioactive decay. The elements such as aluminium (2), boron (3) or magnesium (4) become the source of another radiation after being bombarded with the alpha radiation, and they start to act like radioactive elements. After removing the source of the alpha radiation, these elements emit the positive electron (positrons) and antineutrino for some time. The euphoria of this discovery was dimmed by the bad health condition of Marie Curie- Skłodowska at that time. This great scientist died on 4th July, 1934, because of the illness caused by the long lasting work with the radioactive substances. After her mother’s death, Irene took over many of her functions. She took over the management in the Radium Institute where she studied the properties of the radioactive elements. The discovery of the artificial radioactivity gave Frédéric and Irene Joliot-Curie in 1935 the Nobel Prize in the field of chemistry. It gave the new direction for the actions not only in physics and chemistry, but also in biology, medicine and technology. From 1936 Irene and Frédéric worked separately, because Joliot took over the professorship in College de France. At the end of the 30’s of the 20th century, Irene became the Under-Secretary of State in terms of scientific research in the French government, and in 1937 she took over the chair of the General Physics and Radioactivity in Sorbonne University. During 34 years of work, Irene published over 30 scientific papers, most of them she published together with her husband. In 1946 she wrote a monograph on radioactivity. She should be also owed the editing and publishing of “Radioactivity” by Marie Curie-Skłodowska after her death. Irene Joliot-Curie was made an officer of the Legion of Honor in 1939. Besides very involving scientific work, Irene Joliot-Curie took part also in the social-political activity, although she was not in any political party, like her mother. She was involved in the activities concerning world peace. As a result, she was chosen to be the member of the World Peace Council in 1950 during the second World Peace Congress. She enrolled to the French Women Association during her studies, to fight for the equal rights for women. She was also interested in education of students. She was given the honorary doctorate by many universities, including Polish Biography: Irène Joliot-Curie 3 Storytelling Teaching Model: wiki.science-stories.org © 2012, S@TM Research Group universities: the University of Marie Curie- Skłodowska in Lublin (1950) and the Jagiellonian University in Cracow (1951). Irene Joliot-Curie showed friendship for Polish scientists. She visited Warsaw few times and supported the rebuilding of the Polish scientific institutions destroyed during the war. During last years of her life, her health broke down. The long-lasting contact with the radioactive substances left the negative trail. She died of leukaemia, like her mother. On the 17th March 1956 in France the day of mourning was announced. The children of Joliot-Curie's, daughter Helene and son Pierre, also became acknowledged scientists. References Andrzej Kajetan Wróblewski, Historia fizyki, Wydawnictwo Naukowe PWN 2011 Catherine M.C. Haines, International Women in Science: A Biographical Dictionary to 1950: Irena Joliot-Curie Cezary Pawłowski, Irena Joliot-Curie 1897-1956, Postępy Fizyki, Zeszyt 4, str. 367 (http://www.ifpan.edu.pl/ON- 1/Historia/) F. Joliot and Irena Joliot-Curie, Nobel Lecture in Chemistry, 1935 Elsevier Publishing, Co.,Amsterdam, 1966) Irena Joliot-Curie, Naturalne pierwiastki promieniotwórcze, Wydawnictwo Naukowe PWN 1954 Magdalena Gawin, Niezwykłe kariery, Academia – Magazyn Polskiej Akademii Nauk, 4/11 (28) (http://www.academia.pan.pl/dokonania.php?id=649&jezyk= pl) http://www.if.pw.edu.pl/~pluta/pl/dyd/mtj/zal1/pz03/budzilo /4g.html Biography Irène Joliot-Curie is based, in part on Historical Background: Atoms written by Peter Heering. Biography: Irène Joliot-Curie was written by Wojciech Olszewski with the support of the European Commission (project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and Polish Association of Science Teachers, Poland. This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein. EN_Guidelines_Joliot Curie.pdf Suggestions to Teachers (Joliot-Curie and artificial radioactivity) 1 Storytelling Teaching Model: http://science-story-telling.eu Suggestions to Teachers (Joliot-Curie and artificial radioactivity) Expected results After the lesson, the students are expected to: 1. Write a text demonstrating, why the discovery of neutron was not attributed to Irene and Frederic Joliot – Curie while they had successfully implemented the relevant experiments but to Chadwick, based on the narration as well as the lesson activities. 2. Write a text demonstrating, how the science is progressed, based on the narration as well as the lesson activities. 3. Write certain characteristics the Nature of Science, based on the narration as well as the lesson activities. 4. Describe the principal properties of the positron, based on the suggested data resources or by their research in the web. 5. Verify the conservation of the mass and the electric charge in the both sides of the reaction, during the transmutation of the aluminum into phosphorus, according Juliot Curie’s experiment. 6. Make inquiry in the web and to write a text about the artificial radioactivity and its uses for the benefit of humankind. About the activities of students The proposed students' activities are indicative and they aim at the accomplishment of the above expected outcomes. Moreover, the teacher may choose some of them for the teaching process in relation to its aims, the needs of students and the available time. Finally, she/he can create her/his own activities. About the emergence of the characteristics of science in the narration, these characteristics are quoted in the website, comprehensively (in classification of the stories by NOS). About the locating of the characteristics of Nature of Science in the proposed activities, indicatively, we can quote the following: A) The activity 2 concerns the characteristics of Nature of Science: a) “Scientific knowledge is tentative but durable”, b) “Science demands and relies on empirical evidence” and c) “Science has a subjective element”. B) The activity 3 concerns the characteristics of Nature of Science: a) “Science has a subjective element” and b) “Science demands and relies on empirical evidence”. C) The activity 4 concerns the characteristic of Nature of Science, which are quoted in the above activities 2 and 3 and the characteristic: “Knowledge production in science includes many common features and shared habits of mind” D) The activity 5 concerns the characteristics of Nature of Science: “Science has a subjective element” and b) “Science demands and relies on empirical evidence”. 2 Suggestions to Teachers (Joliot-Curie and artificial radioactivity) Storytelling Teaching Model: http://science-story-telling.eu E) The activity 7 concerns the characteristic of Nature of Science: “Scientific knowledge is tentative but durable”. G) The activity 8 concerns the characteristics of Nature of Science, which are quoted in the above activities 2, 3, 4, 5 and 7. Suggestions to Teachers (Joliot-Curie and artificial radioactivity) were written by Aikaterini Rizaki and Panagiotis Kokkotas with the support by the European Commission (Project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and the NKUA of Greece. This publication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained there in. EN_LA_Joliot Curie.pdf Student’s Learning Activities (Joliot-Curie and artificial radioactivity) 1 Storytelling Teaching Model: http://science-story-telling.eu Student’s Learning Activities (Joliot-Curie and artificial radioactivity) Activity 1 You will watch a video with narration or listen to a story from your teacher about Irene and Frederic Joliot Curie and their work on artificial radioactivity. Please write the most important points of the story according to your view and discuss them in your group. (Indicative important points of this story: description of Irene and Frederic’s experiment, experimental findings of Anderson, experimental discovery of Chadwick, how these discoveries have affected their work, how science is developed,…) …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………..………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………… Activity 2 Based on the narration and the information about the events before the discovery of neutron which are described in the bellow link: http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie- chadwick-discover- neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450 &sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSd wz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW- vYDgBg&ved=0CH4Q9QEwCw write a text in order to explain why the discoveries were not attributed to Irene and Frederic Joliot – Curie while they had successfully implemented the relevant experiments. …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie-chadwick-discover-neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450&sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSdwz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW-vYDgBg&ved=0CH4Q9QEwCw http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie-chadwick-discover-neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450&sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSdwz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW-vYDgBg&ved=0CH4Q9QEwCw http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie-chadwick-discover-neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450&sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSdwz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW-vYDgBg&ved=0CH4Q9QEwCw http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie-chadwick-discover-neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450&sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSdwz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW-vYDgBg&ved=0CH4Q9QEwCw http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie-chadwick-discover-neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450&sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSdwz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW-vYDgBg&ved=0CH4Q9QEwCw http://www.google.gr/imgres?imgurl=http://www.goalfinder.com/images/SPAPRO7/Curie-chadwick-discover-neu.jpg&imgrefurl=http://www.goalfinder.com/product.asp?productid%3D108&h=332&w=450&sz=34&tbnid=MQwPCI2drx4dhM:&tbnh=99&tbnw=134&zoom=1&usg=__FSkeNKeLSO0Z4dSdwz3QourOwD8=&docid=U2euhzetuD9zcM&sa=X&ei=diNiUtTSNaek0QW-vYDgBg&ved=0CH4Q9QEwCw 2 Student’s Learning Activities (Joliot-Curie and artificial radioactivity) Storytelling Teaching Model: http://science-story-telling.eu …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………..………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………… Activity 3 Please visit the website bellow and discuss how Chadwick explained the experimental data of his experiment and discovered the neutron: http://www-outreach.phy.cam.ac.uk/camphy/neutron/neutron4_1.htm Please explain what Chadwick did more than the couple Joliot – Curie, so that the discovery of neutron was attributed to him. …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………..………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… ………………………………………… Activity 4 Could you please explain how science proceeds from the above experiment? …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… http://www-outreach.phy.cam.ac.uk/camphy/neutron/neutron4_1.htm Student’s Learning Activities (Joliot-Curie and artificial radioactivity) 3 Storytelling Teaching Model: http://science-story-telling.eu …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… ……… Activity 5 Please read the following text in order to understand what the couple Joliot-Curie had discovered and why won the 1935 Nobel Prize in Chemistry. “…… Irene and Frederic could do was once again to confirm his experimental findings in which different materials were exposed to α-radiation….. …When a proton is emitted from the Aluminum, it is obvious, we get a Silicon atom. But what kind of atom can be formed when a neutron is emitted? ….if we have a neutron and a positron, that would bring us back to silicon. However, it would be very unusual to have triggered emission of the two particles simultaneously. .. Irene was still looking at the set-up and suddenly became excited: “Frederic look, there is still a trace of a positron.”…. … When we irradiate materials with α-particles, the result is a transmutation of a new element. But this is an instantaneous process. … They had converted aluminum into phosphorus with the emission of a neutron. The phosphorus then underwent positron decay. 27Al + 4He -> 30P + neutron 30P -> 30Si + positron + (neutrino) After that please verify that in the above reaction the mass and the electric charge is the same in both sides of the reaction. Activity 6 4 Student’s Learning Activities (Joliot-Curie and artificial radioactivity) Storytelling Teaching Model: http://science-story-telling.eu Please go to the following site and write a paragraph about the main properties of the positron. http://www.daviddarling.info/encyclopedia/P/positron.html …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………..………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………… Activity 7 In your opinion, what is the difference of the concept of transmutation of elements, in the work of Aristotle, and its modern meaning of the elements that are naturally produced in the radioactive decays or in the production of artificial radioactive elements? Please seek your information in the internet or in other sources available. Use the table below to register and to infer from them. The elements and their transmutation in the work of Aristotle The elements and their transmutation in modern science The difference between the two views Activity 8 From the lesson today one could find some important aspects of NOS. Could you please discuss in your group and identify some of them? Could you imagine yourself in the place of Frederic or Irene? How? …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………….………………………………………………………………… …………………………………………………………………………………………………………………………………………………… http://www.daviddarling.info/encyclopedia/P/positron.html Student’s Learning Activities (Joliot-Curie and artificial radioactivity) 5 Storytelling Teaching Model: http://science-story-telling.eu …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… ……… Activity 9 Please write a text about the artificial radioactivity and its uses today for the benefit of man and the society as a whole, researching in the internet and exploiting the new knowledge we constructed from today’s lesson. …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………..………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………… …………………………………………………………………………… Student’s Learning Activities (Joliot-Curie and artificial radioactivity) were written by Aikaterini Rizaki and Panagiotis Kokkotas with the support by the European Commission (Project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and the NKUA of Greece. This publication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained there in. Historical background atoms.pdf Background Atomsatoms 1 Storytelling Teaching Model: http://science-story-telling.eu Background atoms The concept of Atoms is fundamental to our modern scientific understanding of the world. The em- inent physicists Richard P. Feynman pointed out that “[i]f, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of crea- tures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms – little particles that move around in perpetual motion, attracting each other when they are little distance apart, but repelling upon being squeezed into one another” (Feynman et al. 1963, I- 3). This quotation is for several reasons relevant with respect to this historical background: On the one hand, Feynman is pointing out extremely clear how important the concept of an atomic struc- ture of matter is to modern science. Yet, he also raises implicitly another issue that is very relevant if the genesis of this concept is analysed: Feynman speaks in this introduction to the first lecture of the ‘atomic hypothesis (or the atomic fact, or whatever you wish to call it)’, and in doing so he ad- dresses and ignores at the same time a crucial detail: is the existence of the atom an hypothesis, or is it a fact, and if so, what really is part of this fact – which level of description can still be taken as being a fact, which are additional hypothesis. Feynman ignores this issue by leaving it to the reader how she or he wishes to call it – this appears to be a crude form of relativism that can possibly be explained by looking at the date of the publication: Feynman’s lectures date from the early 1960s, for that time it appears to be questionable whether a different position could be expected in epis- temological or in nature of science categories. Such a statement appears to be somewhat irritating from our point of view, yet, it demonstrates how far the knowledge about the nature of science has developed in recent decades. In order to teach this central concept, one aspect gets relevant which was also important in the historical development but will not be discussed in this historical background: The notion of a chemical element is a prerequisite for the formulation of the atomic model – this can be seen in the historical analysis booth for the development in the Greek antiquity as well as for the modern period, and it can also be identified in the educational conceptions. How- ever, the historical development of the concept of elements will not be discussed in this back- ground material but is assumed to already ex- ist. Ancient discussions about the structure of matter The question how the material world is structured has been discussed in particular in Greek Antiquity (a knowledge which is in part due to the transfer of knowledge from this pe- riod to the Early Modern Era in Europe).1 In this respect, the topic of a prime element that 1 There is evidence that models of the material world existed also in the Indian culture as well as in Babylonian culture, however, documentation is poorer and these concepts have not played any role in the introduction of an atomic theory into Europe- an science – thus they are not discussed in the back- ground. constitutes all the other substances becomes relevant, however, it is of course not even syn- onymous with a simplistic atomic concept as this prime element could exist without any corpuscular structure. Philosophers such as Thales of Miletus, Anaximenes, Heraclites and Empedocles were among those scholars who developed or promoted respective conceptions. About 450 BC, two philosophers developed ideas that are relevant to the introduction of the atomic conception: Democritus and Leucip- pus. Both postulated that the material world is made from very tiny particles, which them- selves cannot be any further separated into smaller parts. These atoms were distinguished from each other by their shape and size. Ac- cording to Democritus, these atoms move in the empty space and collide with each other. By specific combinations of atoms, other sub- stances are formed, yet, these combinations are not permanent but the atoms can separate again. However, the concepts of Leucippus and Democritus were not accepted by their con- temporaries: “Two factors weighed against any widespread acceptance of the classical version of atomism. The first factor was the uncom- promising materialism of this philosophy. By explaining sensation and even thought in terms of the motions of atoms, the atomists chal- lenged man’s self-understanding. Atomism seemed to leave no place for spiritual values. 2 Background Atoms Storytelling Teaching Model: http://science-story-telling.eu Surely the values of friendship, courage, and worship cannot be reduced to the concourse of atoms. Moreover, the atomists left no place in science for considerations of purpose, whether natural or divine. The second factor was the ad hoc nature of the atomists’ explanations”. (Loose 2001, 25) Additionally, there was a rival concept which appeared superior as it ex- plained the behavior of matter: the four ele- ments conception which explained all existing matter as well as its properties through four elements: Water, Air, Fire, and Earth.2 A central, if not the central figure for the re- jection of this atomic theory was Aristotle, who advocated the four elements theory and added as a fifth: ether, which filled the space between the celestial bodies. This was relevant as – ac- cording to Aristotle – no empty space could exist – the horror vacui, nature’s ‘fear’ of emp- tiness. Moreover, according to his conception, everything in nature is intentional; there is no superfluous action in nature. Additionally, each object has a natural position, and if displaced, it aims at getting back to this position. Conse- quently, Aristotle was able to explain observa- ble processes with his principles. The atomists were not only unable to propose a superior explanation, even more: they assumed the ex- istence of particles no one could see. This was a major criticism Aristotle made against the atomic theory, apart from that he did not ac- cept the idea of the empty space which was according to his own conception impossible. And a permanent motion appeared absurd in Aristotle’s understanding. All in all he opposed the atomic concept which was in contradiction to several of his central beliefs. Yet in some sense he is still relevant to the modern devel- opment of the atomic theory as the original works of Leucippus and Democritus were lost and were actually known only through his criti- cism. Aristotle’s works were kept and expanded in the Islamic culture, and through this culture, they came back to Europe and the Christian culture. For the scholastic period, this Aristote- lian understanding became dominant, particu- larly as it was considered to be coherent with 2 It has to be understood that these elements were not what we call Earth, Fire, Air, and Water, but they are elementary principles (see also the background on the development of the Periodic Table). the Bible. Yet, astronomers and slightly later natural philosophers developed a different understanding of natural processes – conse- quently the authority of Aristotle was more and more questioned throughout the 17th and 18th centuries – at the end of this period, it was the experimenting enlightened natural philosopher who was considered to be able to uncover the laws and structure of nature. In this process some experiments and considerations were developed that seemed to strengthen the an- cient atomic hypothesis. Of particular im- portance was the demonstration of the exist- ence of the vacuum.3 In another argumentation it was discussed that if a tiny bit of incense is burned, it can be smelled in the entire room. As this room is significantly bigger than the space the incense initially occupied, the initial piece has to be divided into more than 750.000.000 parts – these calculations were intended to show how small the particles have to be that form the piece of incense (see Beer & Pricha 1997). However, such a discussion remained on the level of simple calculations, there was no claim whatsoever that atoms exists or what their properties might be. Such an understand- ing was only developed in the early 19th centu- ry. Structuring matter: Dalton When looking into the genesis of modern science, probably the first scholar to establish an atomic conception is John Dalton, a chemist who was following Lavoisier’s new, quantita- tive approach towards chemistry. Using a bal- ance to analyze chemical reactions formed a major achievement of Lavoisier’s new chemical system, and this enabled chemists to take a different perspective on chemical reactions. Lavoisier himself established the difference towards classical chemistry and the novelty of his approach several times, to give but one ex- ample: “Lavoisier wrote in the Opuscules phy- siques et chimiques (1774) that he ‘applied to chemistry not only to the apparatus and meth- ods of experimental physics but also the spirit of precision and calculation which characteriz- es that science’.” (Nye 1993, 35). Yet, it was not only the methodological step or conceptual modifications that made Lavoisier’s chemistry 3 On some of the controversies with respect to the existence of a vacuum and the related philosophical implications see Shapin & Schaffer 1989. Background Atoms 3 Storytelling Teaching Model: http://science-story-telling.eu distinct to the previous understanding. A key element in his chemistry was the different no- tion of chemical reactions that helped him to use the quantitative description, and the un- derstanding that ‘simple substances’ can be interpreted as elements that cannot be decom- posed any further. In this respect, Lavoisier stated explicitly: “I shall, therefore, only add upon this subject, that if, by the term elements, we mean to express those simple and indivisi- ble atoms of which matter is composed, it is extremely probable we know nothing at all about them; but if we apply the term elements, or principles of bodies, to express our idea of the last point which analysis is capable of reaching, we must admit, as elements, all the substances into which we are able, to reduce bodies by decomposition.“(Lavoisier 1794, xxiii) Remarkably, Lavoisier is already using the term ‘atom’, even though he is not using an atomic theory. However, this notion of element that gets evident in this quotation is also rele- vant to the introduction of the atomic theory. A key understanding resulted from the quantitative observations at the end of the 18th century: most compounds are the result of the reaction of specific ratios of masses of the ele- ments that form this compound. This rule be- came known as the law of constant composi- tion. Even though this law appeared to be valid for the chemical reactions that had been ana- lyzed quantitatively, there was another striking aspect, and this was first characterized by John Dalton. Dalton realized that there were some chemical reactions in which different com- pounds were formed through a combination of the same elements (i.e. from a reaction of cop- per with oxygen two different compounds can result, likewise carbon and oxygen, and so on). The resulting compound depended on the amount of the two initial substances that react- ed with each other. However, there was also some regularity that Dalton noticed: there was a ratio of small integer numbers between the masses of element A that reacted with the same amount of element B to two different com- pounds. From this finding Dalton formulated another law. the law of multiple proportions characterizes that if two elements possibly re- act to more than one compound, then the masses of element A reacting with the same amount of B are small integer multiples. This law, together with the law of constant composi- tion, forms the starting point towards the stoi- chiometric approach in chemistry. However, even though this law was based on empiric evidence, it was not the only conclu- sion that Dalton drew from his experiments: In a lecture delivered at the Royal Institution London4, he proposed the following ideas which form the basis of the modern atomic theory of matter: “All matter is composed of atoms Atoms cannot be made or destroyed All atoms of the same element are identical Different elements have different types of atoms Chemical reactions occur when atoms are rearranged Compounds are formed from atoms of the constituent elements.”5 Evidently, Dalton’s use of the term atom is different to the one of Lavoisier. Dalton’s con- ception of the atom is characterized by their countability, they have a certain weight and so on, whilst in Lavoisier’s conception it is more their chemical property which is relevant, and it is even unclear whether this is an actual par- ticle. This assumption enabled Dalton to prepare an explanation of the stoichiometric laws he and others had formulated. According to this understanding, the law of constant composition results both from the understanding that all atoms of the same element are identical, and that chemical reactions are a result of the rear- rangement of the atoms. The law of multiple proportions can then be interpreted as being the result of different arrangements of the at- oms that result in different compounds. In do- ing so, the knowledge about quantitative chem- ical analysis became based on a first paradigm in the Kuhnian sense (and in this respect, one could argue that this achievement turned stoi- chiometric chemistry into a science in the Kuhnian sense). Yet, things were not that easy: Even though Dalton’s theory was adopted by several chemists very quickly, others rejected it. A key problem was the assumption that each element was formed by a different atom, as a result there were about thirty different atoms at the beginning of the 19th century, and their number was increasing. Thus, instead of simpli- fying the structure of matter, Dalton’s atomic 4 According to Clarke (1803), the first presentation was made at the Manchester Philosophical Society. 5 http://www.rsc.org/chemsoc/timeline/pages/1803 .html, last access April 18, 2012 4 Background Atoms Storytelling Teaching Model: http://science-story-telling.eu theory made nature more complex. Despite this criticism, the stoichiometric laws were used by chemists, and some of them used fractional numbers to express the ratio of masses – indi- cating that there was no inseparable particle. This was not just a problem of initial ac- ceptance, even sixty years later, reservations against this theory were stated very explicitly, e.g. the President of the Chemical Society Wil- liamson stated in a speech in 1869: “… that on the one hand, all chemists use the atomic theo- ry, and that, on the other hand, a considerable number of them view it with distrust, some with positive dislike.“ (quoted in Tilden & Glasstone 1926, 227). And some renown chem- ists and physicists at the beginning of the 20th century still rejected the atomic theory – we will come back later to this issue. Yet, particu- larly for chemists, the atom became an entity that was used in their analysis of chemical reac- tions. However, it was not considered to be real (neither in the positivistic sense nor in the sense of a relevant theoretical description) but just a heuristic tool which was very adequate in terms of describing chemical reactions, but had nothing to do with the actual understanding of matter (Görs 1999). The atom gets established Despite the discussions amongst the chem- ists who accepted the atom as a useful hypoth- esis, the physicists started to use the atom as a real object with explanatory power. Particular- ly the developing science of thermodynamics played an important role in the establishment of a physical atom that is crucial for the kinetic theory (atoms in motion represent heat). How- ever, this understanding was strongly criti- cized, particularly in the German speaking sci- entific community by eminent scientists such as Ernst Mach, Wilhelm Ostwald and Georg Helm.6 The controversy between these re- searchers (Ostwald was a Nobel Prize winner in 1909, Mach was also very prominent in his times) and the proponents of a statistical inter- pretation (most notably Boltzmann) was not just based on physical issues but involved also deep philosophical questions. A key aspect in 6 For other reasons, also Max Planck initially criti- cized atomism as he understood it in Boltzmann’s statistical interpretation, see Müller (2008). This discussion was not limited to the German speaking community; another example of the opponents of atomism is Poincare this respect was the question whether individ- ual atoms can be seen, or whether there is any evidence for the existence of individual atoms. Actually, at the beginning of the 20th centu- ry, it appeared that the atomic theory was con- sidered to be overthrown, and Boltzmann to be a relic from the 19th century. Things changed significantly when Planck’s theory of radiation was established and at about the same time Einstein and Smoluchowski published their interpretation of Brownian motion. This was a phenomenon described already in the 18th century by several observers. However, it was attributed to the biologist Robert Brown who noticed in the early 19th century that small pollen and dust particles that are floating on water moved in an erratic manner. The re- markable detail about this motion was that it never appeared to stop, moreover, the moving particles were certainly not alive. It remained an open question for about half a century how this motion was to be interpreted. Even though towards the end of the 19th century some re- searchers proposed solutions to this question which correspond to our interpretation, it was only in 1905/06 when Albert Einstein and Mar- ian Smoluchowski presented independently their mathematical analysis of Brownian mo- tion (actually Einstein’s paper was one of the three famous in his annum mirabilis, the other two dealt with the photoelectric effect and the special theory of relativity). Both researchers were able to explain that the motion can be caused by the motion of the particles of water due to their kinetic energy – thus, Brownian motion appeared to be a first macroscopic ef- fect that had to be explained with the assump- tion of small particles and thus forming an em- pirical evidence for the kinetic theory and thus for the atomic theory. Actually, Ostwald is said to have been convinced of the adequateness of the atomic theory through the agreement of the description and the empirical data. At about the same time, there was another empirical evi- dence for the adequateness of the atomic theo- ry, and this one is said to have convinced Mach: When radioactive particles are placed next to a fluorescent screen, minute flashes of light can be observed which are to be interpreted as results of individual α-particles. Thus, within a few years, the understanding of atomism had changed from almost complete rejection to almost complete acceptance. Boltzmann, the great proponent of the atomic theory, was at Background Atoms 5 Storytelling Teaching Model: http://science-story-telling.eu that time already dead – he committed suicide in September 1906. The atom gets a substructure Even before Einstein’s and Smoluchowski’s work helped to establish a consensus about the correctness of the atomic description of matter, some researchers established empirical results that actually contradicted the initial under- standing of the atom as being inseparable: Ac- tually Faraday’s work on electrolysis – which dated from the 1830s –could have been raised questions on the fundamental and inseparable nature of the atom as formulated by Dalton: According to Faraday’s investigation, a certain amount of electricity releases a certain amount of an element in the process of electrolysis. However, this empirical result did not raise questions with respect to the atomic nature of matter, on the contrary: It remained unclear until well into the 20th century whether elec- tricity has an atomic structure, or whether the ratio between electrical charge and released matter was the mean of several reactions that could take place at the same time. Only in the 1920’s, when Millikan’s measurements on the elementary charge were awarded with the No- bel Prize, this issue had been settled (at least for the vast majority of scientists, see Holton 1978). Yet, towards the end of the 19th centu- ry, further evidence was produced that ques- tioned the indivisible character of the atom. Actually, the starting point was research that in retrospect can be taken as being further evi- dence for the atomic theory, even though it was not interpreted in this sense in the historical situation. In the 1860’s, the chemist Bunsen showed, together with the physicist Kirchhoff, that the light emitted from a substance is very characteristic and that only special frequencies (or lines, if the spectrum is analysed) are emit- ted (or absorbed). This provided also a method to identify new elements, and the number of elements increased significantly over the next few years. Analysing spectra was a major issue, and became expanded towards analyzing also cathode rays and their interaction with gases that are filled into the tubes. In doing so, exper- imentalists had hoped to develop a further un- derstanding about the constitution of matter (Müller 2004). Particularly the analysis of cathode rays appeared to be very promising; among the researchers working in this field was J.J. Thomson. Thomson analyzed these cathode rays and established that they are formed by particles7 which have a mass of about 1/1000 of the hydrogen atom. He was also able to determine the mass-charge ratio by deflecting these particles in a magnetic field. However, what might be more relevant to this discussion are his experiments in which he used different cathode materials to emit the rays (which were basically emitted by heating up the cathode, the rays were then accelerated with an electric field). Thomson could show that all particles have similar properties, no matter from which material they were emanat- ed. This could be seen as an indication that these particles (corpuscles, as Thomson called them) were a fundamental part of matter. However, there was a problem: When these corpuscles were that lightweight, but electrical- ly charged, and they form a part of matter, then how can stability be created? Thomson finally came up with a solution: “We suppose that the atom consists of a number of corpuscles mov- ing about in a sphere of uniform positive elec- trification …” (Thomson 1904, 255).8 This meant that the (at this time still disput- ed atom) was no longer indivisible, and that the model of the atom had to be modified. Another modification became necessary soon after- wards, and this was related to another field which emerged in the very early 20th century: radioactivity - which will be discussed in the next chapter. One of the researchers who estab- lished their scientific career in analyzing this phenomenon was Ernest Rutherford, a physi- cist from New Zealand who did his early re- searches (which won him the Nobel Prize) in Canada and then moved to England again. In the Cavendish laboratory two of his assistants – Marsden and Geiger – carried out the experi- ment to scatter α-particles with metal foils (Geiger & Marsden 1909). 7 Quite remarkably, his son George Paget Thomson was also awarded the Nobel Prize in physics, this time for his work on electron diffraction. In some sense, it could be (admittedly oversimplified) ar- gued that J.J Thomson was awarded the Nobel Prize for demonstrating that electrons were particles, whilst his son was awarded the same honor for demonstrating that electrons are no particles but have also a wave character. 8 Actually the Japanese physicist Nagaoka came up with a similar solution one year earlier. 6 Background Atoms Storytelling Teaching Model: http://science-story-telling.eu Rutherford had already suspected that a scattering is possible when he observed the passage of α-particles through sheets of mica. This experiment was taken up again, and the result was more than irritating (even though not completely unexpected: Geiger and Marsden observed that even though the vast majority of α-particles passed the metal foil (and in the course of the experiment they used gold foil as this could be prepared extremely thin), with some of them being scattered, very few of them were reflected. “In retrospect, Marsden’s discovery was the ‘most incredible event’ that had ever happened to him [Rutherford, PH], almost as incredible, he would say, as if a fifteen-inch shell fired at a piece of tissue paper bounced back and hit the gunner. That the military imagery and the in- credulity are later fabrications we can see easi- ly from a lecture Rutherford delivered … six month after the discovery of the diffuse reflec- tion (Heilbron 1981, 264f.) Be this statement as it may, the result was certainly unexpected to the scientific communi- ty, and Rutherford came up with an explanation that was certainly also unexpected: He calcu- lated from the behavior of the α-particles that the atom had a small positively charged nucle- us that contains almost all the mass, whilst most of the space of the atom was empty, ex- cept for the electrons that moved around somewhere in this space. Atoms can change As already mentioned, Rutherford became famous for his researches in radioactivity – yet he was not the person to open this field. The first researcher who actually observed radioac- tivity was the French physicist Henri Becquerel – his discovery (and one can use this term as this was completely unexpected even though some sensibility for radiation effects certainly existed due to Röntgen’s demonstration of the X-rays) opened a new field. Yet, this field was not entered immediately by Becquerel himself or other scientists, but the rays emitted from Uranium salts were just considered to be a cu- riosity not worth any further scientific atten- tion. It was the collaboration of a young Polish chemist with a French physicists that actually made the importance of this new field evident: Marie and Pierre Curie could use the radiation to show that within several radioactive samples other elements than Uranium have to exist as the radiation was stronger than the one emit- ted from pure Uranium. In a long and laborious analysis, they were finally able to prepare pure samples of the elements Polonium and Radium. Particularly Radium became central to the re- search in the new field of radioactivity as it was fairly active and produced different rays. Yet, it became evident, that a lot more chemical ele- ments have the ability to emit such a radiation. However, there were several things that turned out to be really astonishing – among them cer- tainly the transformation of one element into another in the process of an α- or a β-decay. This gets evident from an anecdote that brings us back to Rutherford: “Rutherford and Soddy found, for example, that radioactive thorium, atom by atom, was gradually turning itself into radium. At the moment he realized this, Soddy … blurted out, ‘Rutherford, this is transmuta- tion!’ ‘For Mike’s sake, Soddy,’ his companion shot back, ‘don’t call it transmutation. They’ll have our heads off as alchemists” (Weart 1988, 5f.). Already the work of the Curies’ had estab- lished a fundamental idea: The radiation of a material is related to some properties of the element. Uranium has a different radiation than Polonium and Radium, and so on. Moreover, it became evident through experiments that the activity of a sample gets reduced over time – which is evident when the transformation of the atoms into those of another element is tak- en into consideration. However, there was also a problem with respect to the decrease of the activity, it became evident that the half-life was not a value that could be used for an individual atom, on the very contrary. The law of radioac- tive decay worked only for a statistical sample, a prognosis of the behavior of the individual atom was not possible. Initially, this was taken to be an indication of the required development in atomic physics, however, it became evident in the end that this is simply not possible and the decay can only be described mathematical- ly in terms of the statistic of the ensemble. Moreover, in analyzing the radiation, three different types could be identified and soon characterized. Another surprise came with the α-rays – they turned out to be helium, an ele- ment that until then was only detected in the Background Atoms 7 Storytelling Teaching Model: http://science-story-telling.eu sun (with spectroscopic methods) and seem- ingly did not exist on Earth. Yet, as the α-rays appeared to be positive particles whilst the β- rays were electrons, this meant that not only the electrons could be emitted from the atom but also some of the positive substance. Physical atoms and chemical atoms Determining the properties of the different rays was one of the first things that experi- menters did once it became evident that this was a relevant topic. Among other things, mass and charge of the particles that formed the rays were determined. This was done by applying a well defined magnetic field rectangular to the direction of the rays – from the deflection the charge/mass ratio could be determined. A comparable set-up was used to analyze atoms, and this provided another insight into their structure as well as it solved one of the remain- ing problems. Particularly through the work of Francis Aston, who modified this set-up into a mass spectrometer, it became evident that even though from a chemical point of view all atoms of an element are indistinguishable, this was not the case from the physical point of view. Aston could demonstrate that for several ele- ments different atoms existed that could be distinguished (and only be distinguished) from their mass. This helped to explain why certain elements had an atomic weight that was not an integer multiple of the mass of the hydrogen atom. From Aston’s data it became evident that the atomic weight was the weighted mean of the atoms’ mass. Looking at the masses of each kind of atoms (which were predicted and called isotopes already before by Rutherford’s collab- orator Soddy) it became evident that the atom- ic weight of each individual isotope was (within the accuracy) an integer multiple of the Hydro- gen atom. Atoms can be changed Whilst most experiments with radioactive substances aimed at analyzing the radiation, some researchers also attempted to modify atoms (artificial ‘transmutation’). Initially, α- particles were used, they were shot towards matter and it could be observed that some at- oms were able to integrate the α-particle in the nucleus, thus forming a new element. The first to establish this experiment was again Ruther- ford who could show that when α-particles are sent through Nitrogen, Hydrogen and Oxygen are traceable. Rutherford’s interpretation was that the Nitrogen nucleus was absorbing an α- particle, and the newly formed nucleus would immediately emit a hydrogen nucleus. This was the first successful attempt to modify an ele- ment and to create a new one – other such ex- periments quickly followed. Yet, it has to be understood that this is not a nuclear fission, this was still considered to be impossible. Rutherford named the Hydrogen nucleus proton, and postulated that this proton is an elementary component of all nuclei. Yet, the mass of the nuclei does not form integer multi- ples of the mass of the proton, this was still a major problem. At the same time, two more questions still existed: Why can positive pro- tons form the nucleus, and how to explain a β- decay. Rutherford assumed that also electrons exist in the nucleus and form pairs together with protons, and these pairs should keep the elementary particles in the nucleus together. Among the researchers that tried to investi- gate the nucleus and the atom through interac- tion with α-particles were Irène Joliot-Curie (daughter of Marie Curie) and her husband Frédéric. They repeated some experiments which had been carried out in Berlin: Beryllium was irradiated with α-particles; as a result a significant radiation could be observed which they initially took as γ-rays. The particles of this radiation were not charged and appeared to have an extremely high energy. Even though the particles were not charged, they could in- teract with hydrogen and release electrons. Whilst the Joliot-Curies kept their interpreta- tion of the result of their experiments being γ- radiation, James Chadwick, who was working with Rutherford, choose a different interpreta- tion. According to Chadwick this radiation was to be explained with a new corpuscle and thus the radiation was a completely new type. Fur- ther experiments showed that the particles had a rest mass similar to the proton, and could be seen as the particle that replaces the proton- electron-pair Rutherford had assumed to ex- plain the (relative) stability of the nucleus. The neutron enabled further experiments on transmutation, as it is neutral, there is not the repulsive electrostatic force that was a problem in attempting to get an α-particle into the nucleus. Several researchers worked on 8 Background Atoms Storytelling Teaching Model: http://science-story-telling.eu this field as it enabled the creation of new radi- oactive isotopes as well as new products of decay. Among those researchers were the Jo- liot-Curies in Paris, Fermi in Italy, and Hahn and Strassmann in Berlin. Both aimed at getting a neutron into the nucleus of Uranium, at that time the heaviest element to be known. The idea was to produce the so-called transuranium elements, elements with a greater atomic num- ber than Uranium. This appeared to be the only possibility to develop new elements as the Pe- riodic Table was considered to be complete. Particularly the chemist Hahn was very un- satisfied with his results: It appeared that through his experiments, Uranium had been turned into Barium – which has significantly lesser atomic weight than Uranium. Hahn ad- dressed this issue in a letter to the physicist Lise Meitner. She had been working with Hahn for a long time and recently had to flee to Swe- den from the threat of fascist Germany after the so-called Anschluss of Austria. Meitner re- sponded initially that such a result does not seem to be plausible.9 However, as she pointed out in the same letter, there had been so many surprises in the history of radioactivity that one could hardly could say, this or that is impossi- ble. Hahn insisted that he had verified Barium, and Meitner pointed out in another letter writ- ten a couple of days later that at least from the energetic point of view, a fission could have occurred. In a discussion she had with her nephew Frisch, Meitner came to the idea that possibly the model of the atom had to be thought like a drop – if an object with adequate energy hits that drop, breaks this drop into two smaller ones. Hahn finally published his findings (togeth- er with Strassmann) and pointed out that for him as a chemist, he had to state that the result- ing isotopes behave like Barium, yet he claimed that from the point of physics he was still not convinced that this element could be produced in such an experiment. This changed very quickly, and scientists immediately pointed out that in such a reaction not only a significant amount of energy would be released, but also 9 Before these experiments were carried out, how- ever, the concept of nuclear fission had already been formulated by Ida Noddack already in 1934 when she was criticizing the discussion of Fermi in his experiments on transurane elements. other neutrons, thus, a chain reaction appeared possible. Note that some audiofiles with Protagonists such as Thomson, Rutherford, Hahn etc. are to be found at http://www.aip.org/history/mod/fission/fissi on1/01.html I am indebted to D. Metz (University of Win- nipeg) for his careful proof-reading as well as for comments on the previous version of this background material. References Heidelberger, M. (1993). Die innere Seite der Natur : Gustav Theodor Fechners wissenschaftlich- philosophische Weltauffassung. Frankfurt am Main: Klostermann. Heilbron, J. L. (1981). Historical studies in the theory of atomic structure. New York: Arno Press. Holton, G. J. (1978). The scientific imagination : case stud- ies. Cambridge [Eng.]; New York: Cambridge University Press. Lavoisier, A. L. (1794). Elements of Chemistry. Transl. by Kerr, 4th ed., Edinburgh: William Creech. Losee, J. (2001). A historical introduction to the philoso- phy of science. Oxford [England]; New York: Oxford University Press. Morgenweck-Lambrinos, V., & Trömel, M. (2001). Wissen- schaft und Legende: eine Nachbetrachtung zu Lise Meitner, Otto Hahn und die Kernspaltung: eine Legende aus unseren Tagen. NTM, 9, 29--40. Müller, F. (2004). Gasentladungsforschung im 19. Jahr- hundert. Berlin: Verlag für Geschichte der Naturwissen- schaften und der Technik. Müller, I. (2008). Ein Leben für die Thermodynamik. Vom Zweiten Hauptsatz der Thermodynamik zum Planck- schen Wirkungsquantum. In: Physik Journal 7/3, 39-45. Nye, M. J. (1993). From chemical philosophy to theoretical chemistry : dynamics of matter and dynamics of disci- plines, 1800-1950. Berkeley u.a.: Univ. of California Press. Rife, P. (1992). Lise Meitner: ¬Ein Leben für die Wissen- schaft. Hildesheim: Claasen. Shapin, S., & Schaffer, S. (1989). Leviathan and the Air- Pump: Hobbes, Boyle, and the Experimental Life (1st Paperback Edition ed.). Princeton: UP. Sichau, C. (2005). Atomphysik : historische und fachliche Materialien zur Unterrichtsvorbereitung. Oldenburg: Didakt. Zentrum (diz). Background Atoms 9 Storytelling Teaching Model: http://science-story-telling.eu Simonyi, K. (1995). Kulturgeschichte der Physik: von den Anfängen bis 1990 (2. Aufl. ed.). Thun, Frankfurt/Main: Deutsch. Thomson, J.J. (1904). “On the structure of the atom: an investigation of the stability and periods of oscillation of a number of corpuscles arranged at equal intervals around the circumference of a circle; with application of the results to the theory of atomic structure”. In: Philo- sophical Magazine 6 Volume 7, Issue 39, 237-265 Tilden, W. A., & Glasstone, S. (1926). Chemical discovery and invention in the twentieth century. London: Routledge. Weart, S. R. (1988). Nuclear fear : a history of images. Cambridge, Mass.: Harvard University Press. Background atoms was edited by S. Klassen Background atoms was written by Peter Heering with the support of the European Commission (project 518094- LLP-1-2011-1-GR-COMENIUS-CMP) and the University of Flensburg, Germany. This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the infor- mation contained therein Historical Ressources.pdf A Primary Sources, French Joliot-Curie, Irène/Joliot-Curie, Frédéric: L’existence du neutron: la projection de noyaux atomiques par un rayonnement très pénétrant, Paris 1932. Joliot-Curie, Irène et. al.: Physique nucléaire: un nouveau type de radioactivité : note, Paris 1934. Joliot-Curie, Irène/Joliot-Curie, Frédéric: L’électron positif,, Paris 1934. Joliot-Curie, Irène/Joliot-Curie, Frédéric: Radioactivité artificielle, Paris 1935. B Primary Sources, English Joliot-Curie, Irène/Joliot-Curie, Frédéric: New Evidence for the Neutron, London 1932. Joliot-Curie, Frédéric/Joliot-Curie, Irène: Artificial Production of a New Kind of Radio-Element, London 1934. Joliot-Curie, Frédéric: Nobel Lecture: Chemical Evidence of the Transmutation of Elements, Stockholm 12.12.1935, online available: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1935/joliot-f.... Joliot-Curie, Irène: Nobel Lecture: Artificial Production of Radioactive Elements, Stockholm 12.12.1935, online available: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1935/joliot-c.... Joliot-Curie, Frédéric et. al.: Scientists and Intellectuals Address all Peace Lovers, Paris 1950. C Secondary sources, English and French Biquard, Pierre: Frédéric Joliot-Curie; the Man and his Theories., New York 1966. Biquard, Pierre: Frédéric Joliot-Curie et l’énergie atomique, Paris u.a. 2003. Brian, Denis: The Curies: A Biography of the most Controversial Family in Science, Hoboken, NJ 2005. Goldsmith, Maurice: Frédéric Joliot-Curie: A Biography, London 1976. McKown, Robin: She Lived for Science; Irène Joliot-Curie., New York 1961. Pinault, Michel: Frédéric Joliot-Curie, Paris 2000. links.pdf http://www.youtube.com/watch?v=4u2-eg87o-E& The telegram.pdf Story The telegram 1 Storytelling Teaching Model: http://science-story-telling.eu Story The telegram Irene was alone at home as her husband Frederic had to give a lecture early in the morning. Their two children were taken for a walk by the nanny, and Irene was sitting at her desk trying to finish a research paper. Recently, the political situation had developed quickly, and in some respects un- predictably. The Nazi party had taken power in Germany, and Irene and Frederic had been amongst those French intellectuals who co-founded an anti-fascist movement in Paris. Despite her political engagements, they had also been very active in their scientific research. This was the reason why Irene had to stay at her desk working on the paper instead of going into the laboratory where she would usually be at this time of the day. Out of the blue, the doorbell rang, and while she was still wondering who could be visiting so early in the day, the bell rang again. It must be urgent, and a bad feeling overcame Irene as she rushed to the door. When she opened it, there stood a man in a uniform who said: “I have a telegram for Frederic and Irene Joliot-Curie – it is from the Swedish Academy of Science.” Irene held her breath, and at the same time, several thoughts flashed through her mind, thoughts that started with those stories her mother had told her. Marie Curie was certainly the best known female scientist of her time, and having her as a mother sometimes felt like a burden. But Irene was always keen on science, maybe partly be- cause she loved all those stories her mother told her while she was still a child: stories about her research which she carried out to- gether with Irene’s father who had died when she was only eight years old. And of course, there were those moments which Irene had loved best, when her mother told her about their success in the laboratory finding a new and unexpected truth about Nature. Even though sometimes their findings in the end turned out to be erroneous. And of course there were also stories about the moments when they had received their recognition – most no- tably the story when Marie and Pierre had gone to Sweden to receive the Nobel Prize, the high- est scientific award. She especially liked the fact that Marie was the first female to receive this honor. Incredibily, she was not only the first female to receive a Nobel Prize, but also the first person ever to receive a second Nobel Prize. But then these days of childhood were over, and so were the peaceful times. War broke out when Irene was only 17 years old, and she started working with her mother in military hospitals where they operated the X-ray ma- chines, an innovation to surgery that saved a lot of lives of wounded soldiers. At the same time Irene started to study at the university, physics, of course. After completing her studies she be- came one of the research assistants at her mother’s institute. There, in 1924, she met the handsome and very bright young technical as- sistant Frederic Joliot. She fell in love with him and, even though he was at that time just a technician who was aiming to study physics, and Irene had almost completed her PhD and was superior to him, they married. Life was easy at that time, even though Irene sometimes had the feeling that some of her co- workers saw in her more the daughter of Marie Curie than a researcher by her own right. Espe- cially since, she was also working in the same field of radioactive research. However, she and Frederic gained more and more approval in the laboratory as they were very successfully ap- plying new techniques. Actually, at one point they had been close to making a major break- through themselves. In some of their experi- ments with cloud chambers she and Frederic had observed particles which apparently had strange properties – they were positively charged and thus, they should have been pro- tons. But some measurements seemed to indi- cate that they had about the mass of an electron – this was weird, if not impossible. So what could they do about these experimental find- ings? Q1: Propose how Irene and Frederic may have proceeded with respect to their unusual observation. Q2: Should a researcher set her or his initial experiment aside in order to examine a seem- ingly strange phenomenon? Explain your sug- gestion. At that time, Irene and Frederic had been busy doing other experiments, experiments in 2 Story The telegram Storytelling Teaching Model: http://science-story-telling.eu which different materials were exposed to α- radiation. They discussed whether they should investigate this strange phenomenon further. Irene argued: “Let us set this result aside, it is probably just an artifact of the apparatus – you know how error sensitive the mass determina- tion can be.” Frederic agreed: “Yes, and our experiments with the α-particles are going well – particularly the exposure of materials con- taining Hydrogen show really interesting re- sults – it seems that we have produced another mechanism of emitting free protons.” It was only nine months later when Frederic entered the laboratory with a journal in his hand and said excitedly: “Irene, the new Physical Review has arrived and there is an article by a certain Mr. Anderson. He claims to have found traces of a positive electron which he calls a positron.” Irene took the article, quickly glanced through it, looked carefully at the pictures from the cloud chamber that were printed in the article, and said: “This is very similar to our findings, maybe it was not an artifact after all. We prob- ably should redo these experiments as soon as possible.” They looked at each other and smiled, on the one hand a bit disappointed as they were well aware that it was too late to claim priority for the discovery of positrons, but on the other hand they were pleased to know that their experiments were contributing to the development of scientific knowledge. Q3: Why is Anderson considered to be the researcher who gave the first experimental evidence of the positron? Q4: Is this fair? Explain your opinion. As it turned out, their experimental results actually served as additional empirical evi- dence for the existence of the positron; howev- er, this was just supporting Anderson’s work. But in some sense, things were even more dis- appointing. Irene and Frederic had to learn that the experiments which they had continued in- stead of turning towards the analysis of the strangely behaving particle, had led to similar results. In these experiments, they had traced the particles that were emitted from materials containing Hydrogen when exposed to α- radiation. Initially they had considered these particles to be protons, but then a paper by the English researcher Chadwick appeared in which those particles were characterized as being something new, namely particles without a charge and about the mass of a proton. Once Chadwick had identified these as neutrons, all Irene and Frederic could do was once again to confirm his experimental findings. However, there was something else that puzzled them, something that seemingly had not been noticed by other researchers: Irene wondered, “If Chadwick’s findings are correct, and our data seems to confirm his so-called neutron, then how does it work?” Frederic looked up from his instrument and said in a somewhat frustrated voice: “I really don’t know, Irene. When a proton is emitted from the Aluminum, it is obvious. We get a Silicon atom. But what kind of atom can be formed when a neutron is emitted? And what is worse, we also have these positrons that are emitted as well – I have no idea how to explain that.” “Well, if we have a neutron and a positron, that would bring us back to silicon. However, it would be very unusual to have triggered emission of the two particles simultaneously. Let us carry out the experiment once again.” Irene and Frederic set up the apparatus and started to observe once again. However, the results remained unchanged, and Frederic fi- nally removed the α-particle source. Irene was still looking at the set-up and suddenly became excited: “Frederic look, there is still a trace of a positron.” Frederic looked up and said: “No this can’t be, you probably have just misinterpreted something.” But Irene was sure: “There was still a trace of a positron. Look, there just was another one.” “Impossible” mumbled Frederic, but he came back and took a look himself. He waited. “Nothing”, he said, “I don’t see anything unusual.” But Irene insisted: “This is something we have to check once again.” Q5: What is so exciting about the observa- tion Irene had made? Q6: Should Irene and Frederic repeat the experiment? What if they don’t observe traces of positrons after removing the α-source? Frederic brought back the α-source, they ir- radiated the aluminum foil once again for some time, removed the source and observed the traces. “There!” Frederic and Irene said, or nearly shouted, almost simultaneously. “That Story The telegram 3 Storytelling Teaching Model: http://science-story-telling.eu was a positron, for sure it was” said Irene – and Frederic, nodding with his head, said: “You are absolutely right, but how can this be? When we irradiate materials with α-particles, the result is a transmutation of a new element. But this is an instantaneous process. So how can it be that we have this radiation even though there was no α-source anymore? Only …” He silenced, and they looked both at each other. “Only ...!” said Irene. A casual bystander might have heard some sort of triumphant undertone in this word. Q7: What kind of idea to interpret this result could Irene and Frederic have considered? Irene was still standing in the door, and the man from the telegraphic office looked at her in an expecting manner, holding the telegram in his hand. Finally, Irene was back into the pre- sent, smiled at the man and said: “Do you want me to open that telegram?” The man looked somewhat puzzled and responded: “No, Mad- ame, I just need your signature here.” Irene hesitated, and with her heart beating quickly, she signed and finally received the telegram. Should she open it, or should she wait until Frederic was with her? In 1935, Irene and Frederic Joliot-Curie were awarded the Nobel Prize in chemistry in recognition of their synthesis of new radioac- tive elements. Story The telegram was edited by Brigitte van Tiggelen and it is based, in part, on Historical Background: Atoms written by Peter Heering and on Biography: Irene Joliot Curie written by Wojciech Olszewski. Story The telegram was written by Peter Heering with the support of the European Commission (project 518094-LLP-1-2011-1-GR-COMENIUS-CMP) and the University of Flensburg, Germany. This publication re- flects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.

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• Joliot-Curie and artificial radioactivity

Manchester, England. Young Joule was a delicate child, and was not sent to school. His early educa- tion was commenced by his mother's half-sister, and was carried on at his father's house, Broom- hill, [...] of his brother Benjamin and himself. At the age of 16 Joule was sent to the Manchester Literary and Philosophy Society (Lit & Phil) to be taught chemistry, physics, mathemat- ics. His father hired the

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• Scientific Partnership; James Prescott Joule, William Thomson, and the mechanical equivalent of heat.