Conservation and Innovation : Helmholtz's Struggle with Energy ...

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in fact been possible to discover laws that allow prediction of the origin and progress of many extended series of phenomena with the greatest accuracy. It is in this conformity with law that the intellectual fascination which links the physicist to his subject is based. As in mental science so in natural science, a single fact can provoke curiosity or astonishment, but intellectual satisfaction can only be given by the conformity with law, by the connection of the whole. The Kantian trend is more and more evident : which is the innate faculty of thought that allows us to discover laws and to apply them? "Reason", of course. And the best arena for the forces of "pure reason " is the inquiry into nature. In a very interesting passage Helmholtz makes an assertion of the greatest importance as to the motivations of a scientist: the reward is not only a successful activity or the acquisition of power over a sometimes hostile world, but also the artistic satisfaction of surveying Nature as a regularly ordered whole, an "image of the logical thought of our own mind" 339. This regulative power of reason, this highest scientific activity, this ideal of Kantian and neo-Kantian philosophy has now produced a concrete example that is beneath our eyes : an all-embracing regulative principle, the Law of the Conservation of Force. This law is specially suited to give us an idea of the specific character of natural sciences. It is of utmost interest then that Helmholtz's enunciation of the law is greatly different from the original one: "(it) asserts that the quantity of force which can be brought into action in the whole of Nature is unchangeable and can neither be increased nor diminished" 340. To explain the meaning of quantity of force, Helmholtz refers to its technical application, the amount of work, and analyses the subject in a way that recalls the previous popular lectures, but with greater technical (not mathematical) details and a generous use of good drawings and schemes of contemporary machines. Helmholtz's appreciation of the work of Mayer and Joule in this lecture is relevant, also for a comparison with a later assessment 341. Robert Mayer is here credited with the first statement of the possibility of a universal application of the law of the conservation of force, and Joule with having made: 339 Thus there is something more than"the intellectual mastery of nature"! 340 Helmholtz PL 1873 p.320. 341 "Robert Mayer's Priorität" of 1884, see below.
"a series of important and difficult experiments on the relation of heat to mechanical force, which supplied the chief points in which the comparison of the new theory with experience was still wanting" 342. Joule's experiments are actually given great attention, in contrast with the 1847 Erhaltung. This time, of course, the conversion factors are correct. For the determination of the equivalent through the production of heat from work utilising friction, three series of experiments are recalled: water in a brass vessel (equivalent=424.9 gramme-meters necessary to raise of one degree °C one gramme of water), mercury in an iron vessel (425 and 426.3), conical rings rubbing against each other surrounded by mercury (426.7 and 425.6). The reverse determination, that is, the conversion of heat into work through the expansion of perfect gases, is also discussed; results (also due to Regnault's measurements) give : with air 426.0; with oxygen 425.7; with nitrogen 431.3; with hydrogen 425.3. The agreement between the two set of experiments, realised with such different methods is really remarkable. There can be few doubts that "heat is a new form in which a quantity of work can appear" 343. A comment on the presentation of the principle is necessary here: the expression of the principle above 344 shows once again that the stress is on the correlation of forces, but Helmholtz goes even further in hiding his own conceptual model of central forces that had played such a great role in the original Erhaltung . In the extension of the law to all natural processes, the question of the nature of heat became specially important. "In the answer lay the chief difference between the older and newer views in these respects". Moreover in virtue of the relevance of this question: "Many physicists designate that view of Nature corresponding to the law of conservation of force with the name of the Mechanical Theory of Heat" 345. Thus Helmholtz stresses an element, the conceptual model of heat, which despite being universally acceptable and also accepted, was by no means his own specific contribution to the problem. After an acknowledgement of the results of the kinetic theory of gases due to Krönig, Clausius and Maxwell 346 and 342 Helmholtz PL 1873 p.320. 343 Helmholtz PL 1873 p.349. 344 See note 340. 345 Helmholtz PL 1873 p.342. 346 Helmholtz PL 1873 p.350.
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Fabio Bevilacqua Conservation and I
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different formulations 4 and priori
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and interesting results, despite th
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principle of correlation is express
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principle to the existing empirical
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the origin and meaning of the princ
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Whether physiological research, apa
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In a discussion on the origins of a
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his "Wärme" that one of the differ
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generate a determined equivalent of
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"Bericht", despite the application
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experiments in the most disparate b
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The premise reveals that the struct
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intelligible if it can be referred
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elevant consequence of the deductio
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Needless to say the plan was to be
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and from here that the direction an
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since Leonardo 113; the "ad nihilum
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But unfortunately for the whole str
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The principle of conservation of vi
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Page 67 and 68: Finally we get to the real conclusi
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Page 133 and 134: Kant was a Naturphilosophe 480. The
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Blüh, Otto. "The Value of Inspirat
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Graetz, L. "Das Mechanische Wärme
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Helmholtz, Hermann. "Bericht über
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Helmholtz, Hermann. Wissenschaftlic
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Madison: Wisconsin U.P., 1959. Pp.
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Poincarè, Henry. Electricité et O
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Yagi, Eri."Clausius's Mathematical
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