Democritus and the motive power of fire

The present work is a translation from french to english of our previous \g{D\'emocrite et la puissance motrice du feu}, amended on a number of respects. It is mainly of historical and pedagogical interest. We suggest that the concepts introduced in the ancien Greece by Anaximander (flat earth) and Democritus (corpuscles moving in vacuum) allow us to obtain through qualitative observations and plausible generalizations the maximum efficiency and work of heat engines, results that were firmly established around 1824 by Carnot. A prologue introduces the subject. We next present the concept of thermal equilibrium and consider a model consisting of two reservoirs located at different altitudes, each with $g$ sites. Each site may contain a specified number of corpuscles. One particular site plays the role of \g{working agent}. We subsequently consider an alternative model consisting of independent corpuscles submitted to gravity and in contact with heat baths. Only average quantities are considered, leaving out fluctuations and questions of stability.Comment: 57 page

Against “revolution” and “evolution”

Those standard historiographic themes of “evolution” and “revolution” need replacing. They perpetuate mid-Victorian scientists’ history of science. Historians’ history of science does well to take in the long run from the Greek and Hebrew heritages on, and to work at avoiding misleading anachronism and teleology. As an alternative to the usual “evo-revo” themes, a historiography of origins and species, of cosmologies (including microcosmogonies and macrocosmogonies) and ontologies, is developed here. The advantages of such a historiography are illustrated by looking briefly at a number of transitions the transition from Greek and Hebrew doctrines to their integrations by medieval authors; the transition from the Platonist, Aristotelian, Christian Aquinas to the Newtonian Buffon and to the no less Newtonian Lamarck; the departures the early Darwin made away from Lamarck’s and from Lyell’s views. Issues concerning historical thinking about nature, concerning essentialism and concerning classification are addressed in an attempt to challenge customary stereotypes. Questions about originality and influence are raised, especially concerning Darwin’s “tree of life” scheme. The broader historiography of Darwinian science as a social ideology, and as a “worldview,” is examined and the scope for revisions emphasised. Throughout, graduate students are encouraged to see this topic area not as worked out, but as full of opportunities for fresh contributions

Why Is There Motion in our World?

Is there asymmetry in physical processes? Does the physical world evolve toward its state of rest? If it does, why is there motion in our world now? - In this paper, I try to reconstruct to largely distinct answers to these ever exciting questions: (1) the antique answer given by Aristotle, the most influential `scientist´ in antiquity, and (2) the modern answer rendered by the thermodynamic and cosmological theories of our times. By comparing these answers, an attempt will be made to highlight some similarities and differences between them. I try to show that these problems belong, today as well as in Aristotle´s `pre-scientific´ time, to the border region of physics and metaphysics. (An earlier version of this paper is about to appear in Open Systems and Information Dynamics)