Eric Chassefiere – författare

The discovery, in the middle of the 17th century, of both the weight of air and the law governing its elasticity transformed the status of the atmosphere from that of a purely mathematical object to that of a complex and highly variable physical system.In the context of rapidly intensifying experimentation and observation, the nature of the atmosphere was therefore the subject of a host of hypotheses, which 18th century scholars tried to reconcile with a coherent physical approach. In particular, this was achieved by the conceptualization of invisible or “subtle” materials, thought to be closely linked to atmospheric stratification.Subtle matter was introduced, largely to reconcile contradictory results concerning the estimation of the height of the atmosphere. These estimations were based on different methods, mainly using the observation of meteors and the refracted and reflected light of stars.Taking as its common thread the question of the height of the atmosphere, which was omnipresent in the texts at the time, this book traces the history of the discovery of the atmosphere and the many questions it generated.

The discovery, in the middle of the 17th century, of both the weight of air and the law governing its elasticity transformed the status of the atmosphere from that of a purely mathematical object to that of a complex and highly variable physical system.In the context of rapidly intensifying experimentation and observation, the nature of the atmosphere was therefore the subject of a host of hypotheses, which 18th century scholars tried to reconcile with a coherent physical approach. In particular, this was achieved by the conceptualization of invisible or “subtle” materials, thought to be closely linked to atmospheric stratification.Subtle matter was introduced, largely to reconcile contradictory results concerning the estimation of the height of the atmosphere. These estimations were based on different methods, mainly using the observation of meteors and the refracted and reflected light of stars.Taking as its common thread the question of the height of the atmosphere, which was omnipresent in the texts at the time, this book traces the history of the discovery of the atmosphere and the many questions it generated.

The spectacular reappearance of the aurora borealis at the beginning of the 18th century, often observed simultaneously from different observatories in Europe, mobilized and federated a large community of astronomers on a European scale. It encouraged them to communicate the results of their observations and, in compiling exhaustive catalogs of information, has helped to establish a system of the aurora borealis that can be further studied in the future, according to the experimental method inherited from the previous century.

This book is dedicated to some of the main aurora observers in Europe and to the human, institutional and philosophical context in which they evolved in the first half of the 18th century. Its reading should be seen as a retrospective journey through the scholarly world of the Enlightenment, during which the same scholars are frequently encountered and reencountered, yet each time in different contexts, or from different angles, with the aim of compiling an account of the swarming of ideas and encounters that constituted the development of experimental science in this pivotal period.

The spectacular reappearance of the aurora borealis at the beginning of the 18th century, often observed simultaneously from different observatories in Europe, mobilized and federated a large community of astronomers on a European scale. It encouraged them to communicate the results of their observations and, in compiling exhaustive catalogs of information, has helped to establish a system of the aurora borealis that can be further studied in the future, according to the experimental method inherited from the previous century.

This book is dedicated to some of the main aurora observers in Europe and to the human, institutional and philosophical context in which they evolved in the first half of the 18th century. Its reading should be seen as a retrospective journey through the scholarly world of the Enlightenment, during which the same scholars are frequently encountered and reencountered, yet each time in different contexts, or from different angles, with the aim of compiling an account of the swarming of ideas and encounters that constituted the development of experimental science in this pivotal period.

Over the last fifteen years, space-based exploration of the solar system has increased dramatically, with more and more sophisticated orbiters and landers being sent to Mars. This intense period, rich in unprecedented scientific results, has led to immense progress in our perception of Mars and of its evolution over geological time. In parallel, advances in numerical simulations and laboratory experiments also shed new light on the geochemical evolution of the planet Mars. The ISSI-Europlanet Workshop entitled "Quantifying the Martian Geochemical Reservoirs" was held in Bern in April 2011 with the objective to create a diverse interdisciplinary forum composed of scientists directly involved in space-based exploration of the Martian surface, meteoriticists studying SNC meteorites, and planetary and/or Earth scientists simulating, numerically or experimentally, the physical and chemical processes occurring on or within Mars. The chapters of this book provide an overview of current knowledge of the past and present Martian geochemical reservoirs, from the accretionary history to the secondary alteration processes at the surface. In addition to the detailed description of data from Mars and the methods used to obtain them, the contributions also emphasize comparison with features on Earth, providing a perspective on the extent to which our knowledge of terrestrial systems influences interpretation of data from Mars. Areas that would benefit from future work and measurements are also identified, providing a view of the short-term and long-term future of the study of Mars.This collection of chapters constitutes a timely perspective on current knowledge and thinking concerning the geochemical evolution of Mars, providing context and a valuable reference point for even more exciting future discoveries. It is aimed at graduate students and researchers active in geochemistry and space science. Previouslypublished in Space Science Reviews, Vol. 174/1-4, 2013.

Over the last fifteen years, space-based exploration of the solar system has increased dramatically, with more and more sophisticated orbiters and landers being sent to Mars. This intense period, rich in unprecedented scientific results, has led to immense progress in our perception of Mars and of its evolution over geological time. In parallel, advances in numerical simulations and laboratory experiments also shed new light on the geochemical evolution of the planet Mars. The ISSI-Europlanet Workshop entitled "Quantifying the Martian Geochemical Reservoirs" was held in Bern in April 2011 with the objective to create a diverse interdisciplinary forum composed of scientists directly involved in space-based exploration of the Martian surface, meteoriticists studying SNC meteorites, and planetary and/or Earth scientists simulating, numerically or experimentally, the physical and chemical processes occurring on or within Mars. The chapters of this book provide an overview of current knowledge of the past and present Martian geochemical reservoirs, from the accretionary history to the secondary alteration processes at the surface. In addition to the detailed description of data from Mars and the methods used to obtain them, the contributions also emphasize comparison with features on Earth, providing a perspective on the extent to which our knowledge of terrestrial systems influences interpretation of data from Mars. Areas that would benefit from future work and measurements are also identified, providing a view of the short-term and long-term future of the study of Mars.This collection of chapters constitutes a timely perspective on current knowledge and thinking concerning the geochemical evolution of Mars, providing context and a valuable reference point for even more exciting future discoveries. It is aimed at graduate students and researchers active in geochemistry and space science. Previouslypublished in Space Science Reviews, Vol. 174/1-4, 2013.

The discovery, in the middle of the 17th century, of both the weight of air and the law governing its elasticity transformed the status of the atmosphere from that of a purely mathematical object to that of a complex and highly variable physical system.In the context of rapidly intensifying experimentation and observation, the nature of the atmosphere was therefore the subject of a host of hypotheses, which 18th century scholars tried to reconcile with a coherent physical approach. In particular, this was achieved by the conceptualization of invisible or “subtle” materials, thought to be closely linked to atmospheric stratification.Subtle matter was introduced, largely to reconcile contradictory results concerning the estimation of the height of the atmosphere. These estimations were based on different methods, mainly using the observation of meteors and the refracted and reflected light of stars.Taking as its common thread the question of the height of the atmosphere, which was omnipresent in the texts at the time, this book traces the history of the discovery of the atmosphere and the many questions it generated.