A Dynamic Model of the World Copper Industry (Un modele dynamique de l'industrie mondiale du cuivre) (Un modelo dinamico de la industria mundial del cobre)

1978 ◽  
Vol 25 (4) ◽  
pp. 779 ◽  
Author(s):  
Denis Richard
Author(s):  
T. M. Robinson

This article argues the following five claims: 1. Plato’s description of the origins of cosmos in the Timaeus is not a myth, nor something unlikely: when he called it an eikos mythos or eikos logos, he meant a likely or trustworthy account on this very subject. 2. Among the details in this account, the following are prominent and surprising: a) the world was fashioned in time, in that precise point that was the beginning of time; b) several kinds of duration can be distinguished in cosmology (mainly eternity, sempiternity, perpetuity and time); and c) space is an entity characterized by movement and tension. 3. In the Statesman, Plato repeats much the same thing, adding this time the strange notion that the universe’s circular movement is periodically reversed. 4. In spite of the important differences in detail, there is a striking similarity between Plato’s account of the origins of the world and the explanation adopted by much of modern cosmology. 5. What Plato shares with so many instances of recent thought is here termed “cosmological imaginativity”. A first section of the paper deals exclusively with the Timaeus. Claims 1 and 2a are supported by a revision of the meanings of mythos and logos, followed by brief reference and discussion of the argument at Timaeus 27d, leading to the conclusion that Plato affirms that the ever-changing world has indeed had a beginning in time. Claim 2b describes five different types of duration, corresponding to Forms, the Demiurge, Space, the [empirical] world and its contents, physical objects. The second section is concerned with the myth in the Statesman, discussing it as a parallel and describing its peculiar turn to the Timaeus’ cosmology and cosmogony, a complex spheric and dynamic model. After digressing into some important ideas in modern cosmology, touching especially on affinities of some of Einstein’s ideas with of Plato’s own, the paper closes with a discussion of cosmological imaginativity, oriented to recover and recognize fully Plato’s greatness as a cosmologist.


1999 ◽  
Vol 26 ◽  
pp. 449-452 ◽  
Author(s):  
Bruce Fetter

The process of normal scholarship leads young historians to focus on their fields of research with an intensity that is unparalleled during their academic careers. It is no wonder that after a certain interval many change directions, if only to escape the tyranny of the overly familiar. Occasionally, however, we encounter a new approach to our old questions, which forcibly brings us back to our original topic, not with the initial ardor but with the nostalgia of suddenly coming across the photograph of a teenager's crush.Such was my response to discovering Christopher Schmitz's, “The Changing Structure of the World Copper Market, 1870-1939,” in a recent number of the Journal of European Economic History. I wondered just how I would have approached my study of the Central African mines if, between 1963 and 1983, I had had access to this account of the copper industry in its global setting. Mind you, my thirty-one years' experience with undergraduates and master's candidates suggests that it might have made no difference to me at all. So intense is the concentration of our apprentice-historians on their primary materials that it is often difficult to get them to consider contexts beyond those inherent in the sources they use.What was new about Schmitz's synthesis? That is difficult to isolate. He has, indeed, written a series of studies of the copper industry. The article under discussion offers generalizations about the industry as a whole between 1870 and 1939 and the role of various producers and consumers in it for the same period. For the sake of Africanist readers, let me summarize them.


1972 ◽  
Vol 3 (2) ◽  
pp. 568 ◽  
Author(s):  
Franklin M. Fisher ◽  
Paul H. Cootner ◽  
Martin Neil Baily

Author(s):  
J D Burton ◽  
D G Davies

This paper examines the dynamics of one of the oldest pieces of equipment known to mankind, the simple lift pump. These continue to be used in remote areas of the world for lifting water by hand or using wind power. In the case of the smaller modern wind-powered water pumps the speed of operation is such that dynamic factors need to be taken into account when designing the pump. The paper explores the value of introducing softness and elasticity into either the lift rod or the riser support. Output from models describing the pump dynamics are compared with experimental data.


1981 ◽  
Vol 29 (4) ◽  
pp. 867-871
Author(s):  
Walter C. Labys
Keyword(s):  

1983 ◽  
Vol 2 (3) ◽  
pp. 59-63
Author(s):  
John Dryden ◽  
Andreas Tegen ◽  
Raw Materials Group

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