Compendium in Astronomy : A Volume Dedicated to Professor John Xanthakis on the Occasion of Completing Twenty-five Years of Scientific Activities As Fellow of the National Academy of Athens. Questo articolo non è disponibile.Compendium in Astronomy : A Volume Dedicated to Professor John Xanthakis on the Occasion of Completing Twenty-five Years of Scientific Activities As Fellow of the National Academy of Athens

When we first approached some colleagues allover the world to sound them about a volume dedicated to Professor John Xanthakis on the occasion of completing twenty-five years of scientific activities as fellow of the National Academy of Athens, any possible doubts as to the feasibility of the project were quickly dispelled by their warm and encouraging response. In a short time 50 authors from 15 countries, coming from a wide range of Professor Xanthakis' immediate colleagues, pupils and friends joined to produce the 36 contributions included in this volume. Some of those who where originally approached found themselves un­ able to contribute, because of the time-limit necessarily imposed. Happi­ ly, they were only few in number, and we should like to record our grat­ itude to them for their good wishes for the success of the venture. Their warm words were among the many sources of inspiring encouragement extended to us.

I: History and Philosophy.- Episteme and Gnosis. A Tension in European Thought.- A New, Rational Endeavour for Understanding the Eratosthenes Numerical Result of the Earth Meridian Measurement.- Astronomical Activity in the Period 1600 to 1880.- II: Dynamics.- The Behaviour of Adiabatic Invariants near Resonances.- Radiation Pressure Effect on Dust Surrounding the Pleiades Bright Stars.- Trapping of Orbits in Barred Galaxies.- On the Stability of the Asteroids.- III: Solar Physics.- Solar Magnetic Fields and Activity.- The Experimental Curve of Growth in Function of Different Sets of Oscillator Strengths.- Relations of Solar Activity Indices.- Why the Total Solar Radio Flux at a Wave Length of 10cm Cannot Fully Replace the Wolf Relative Sunspot Number.- Increasing Trend of Flare Activity Before the Proton Flare April 30, 1976.- Centimeter Wavelength Observations of Active Regions and Flares with a Few Arc Second Resolution.- A Correlation Between Various Indices of Solar Activity and Solar Cycles.- IV: Solar-Terrestrial Relations.- Caractères Météorologiques du Climat, et Activité Solaire: Quelques Remarques.- A Suggested Approach to Research on the Sun-Weather Problem.- V: Planetary System.- Observations of Zodiacal Light in Egypt and its Variations.- On the Global Size of Oort’s Cloud of Cometary Nuclei and their Total Number.- Voyager Encounters with Jupiter’s Magnetosphere: Results of the Low Energy Charged Particle (LECP) Experiment.- The Weather on Mars on the Basis of the Measurements Carried out by the Vikings Mission.- VI: Stellar Astronomy.- On the Origin of Nebulae.- On Mass Loss from Stars.- Contribution to Fourier Analysis of the Light Curves of Eclipsing Variables.- Prospective Views in Space Astrometry.- Long-Term Changes of the Flare Stars EV Lac and BY Dra.- On the Problem of Cepheid Amplitude Dependence on the Star Position in the Instability Strip.- Early-Type Emission-Line Stars.- VII: Galaxies.- The Structure of the Small Magellanic Cloud.- Large Scale Distribution of Elements and Gravity.- Active Galactic Nuclei and Particle Acceleration in Accretion Disks Around Massive Black Holes.- VIII: Cosmology and Relativity.- Non Linear Einstein-Maxwell Differential Equations.- Recent Results for the Moon’s Secular Acceleration and their Implication for the Possible Variation of G in Dirac’s Large Number Hypothesis.- Classical Phase Space from a Relativist’s Point of View.- IX: Extraterrestrial Intelligence.- The Colonization of the Galaxy. A Key Concept in the Search for Extraterrestrial Intelligence.- X: Associated Fields.- Numerical Treatment of the Magnetohydrodynamic Flow Bounded by an Infinite Porous Plate.- Ray Tracing and Caustics from Large Reflectors Used in Spacecrafts.- Name Index.