The message of sunspots from the interior of the Sun to the Earth's climate When Galileo was summoned before the Inquisition on April 12, 1633, the main accusations laid against him concerned the doubts he expressed about Aristotle's theory of the universe. Aristotle's idea was that the Earth was the centre of the cosmos and that all of the stars, including the Sun, turned around it. Moreover, for Aristotle and the world of the Inquisitors, the Sun was a perfect celestial body. Now, Galileo had discovered spots on the Sun. These spots were seen as imperfections, and not just surface markings, but coming from within the Sun. Worse yet, they revolved around the Sun. All this supported the newfangled theory of Copernicus, and undermined a system of thought that had reigned supreme for centuries. Man of science that he was, and a prudent Catholic too, Galileo strived all his life to prove that Copernicus' astronomical concept was compatible with the word of the Bible. He proposed that there were not two truths but a single divine truth. It was just expressed in two different languages : there was the language of the common people, with its imprecision and inconsistencies, but intuitively understandable by everyone; and then there was the precise language of science with its strict regard for observation, which only a chosen few can grasp [L. Geymonat. 1992].

Klappentext

The Earth experienced numerous cold and warm climatic excursions in the past. There is growing evidence that one of the factors that caused these changes was solar variability. In 35 chapters, leading experts present and discuss the physical mechanisms linking solar forces to the Earth's atmosphere and climate. Among other topics, the solar anomaly in the 17th century and the concomitant little ice age are covered.

Inhalt
The solar dynamo.- The differential solar rotation.- Oscillatory dynamos showing change of parity on a large time scale.- A new reconstruction of solar activity, 16101993.- The Maunder minimum and the solar dynamo.- Panel discussion on The modern status of solar dynamo.- Theories of radius and luminosity variations.- A technique for estimating long-term variations of solar total irradiance : Preliminary estimates based on observations of the Sun and solar-type stars.- Surrogates for total solar irradiance.- Solar forcing of global change.- The observed spatial non-uniformity and temporal variability of the solar limb-darkening function.- Panel discussion on Solar diameter variations.- Atmospheric 14C as a proxy of solar and climatic change.- 10Be as an indicator of solar variability and climate.- Panel discussions on Total solar irradiance variations and the Maunder minimum.- The quasi-biennial oscillation in the Earth's atmosphere and its links to longer period variability.- The quasi-biennial oscillation observed in the semidiurnal ground pressure data and in the ionospheric F layer.- The quasi-biennial oscillation (QBO) : some points about the terrestrial QBO and the possibility of related phenomena in the solar interior.- Sensitivity of climate to variations of the solar output : radiative processes and their parametrization in numerical models.- Climate sensitivity : cloud and water feedbacks and their assessment.- Panel discussion on Putting solar variability in perspective.- Aspects of a decadal Sun-atmosphere connection.- Viewpoints concerning solar activity effects on the atmospheric circulation and climate.- Concerning various types of solar forcing and their effects.- Panel discussion on The solar and climatic relations.- Grasping at shadows ? Aselective review of the search for sunspot-related variability in tree rings.- Perspectives on the climate of the last 500 years.- The 10.8 years solar cycle recorded in sea sediments during the last 4000 years.- Panel discussion on Paleoclimatic data.- Sensitivity of climate to long-term variations of the solar output.- Have solar-irradiance variations influenced climate ?.- Sensitivity of the atmospheric circulation to solar irradiance variations.- Comment on the ocean albedo and absorption.- Panel discussion on Climatic response to variation in the solar forcing.- Summary comments.- Autor's Index.