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. Front Matter....Pages i-xv Front Matter....Pages 1-1 Episteme and Gnosis: A Tension in European Thought....Pages 3-9 A New, Rational Endeavour for Understanding the Eratosthenes Numerical Result of the Earth Meridian Measurement....Pages 11-21 Astronomical Activity in the Period 1600 to 1880....Pages 23-27 Front Matter....Pages 29-29 The Behaviour of Adiabatic Invariants Near Resonances....Pages 31-42 Radiation Pressure Effect on Dust Surrounding the Pleiades Bright Stars....Pages 43-54 Trapping of Orbits in Barred Galaxies....Pages 55-65 On the Stability of the Asteroids....Pages 67-78 Front Matter....Pages 79-79 Solar Magnetic Fields and Activity....Pages 81-96 The Experimental Curve of Growth in Function of Different Sets of Oscillator Strengths....Pages 97-103 Relations of Solar Activity Indices....Pages 105-110 Why the Total Solar Radio Flux at a Wave Length of 10 cm Cannot Fully Replace the Wolf Relative Sunspot Number....Pages 111-115 Increasing Trend of Flare Activity before the Proton Flare April 30,1976....Pages 117-118 Centimeter Wavelength Observations of Active Regions and Flares with a Few Arc Second Resolution....Pages 119-137 A Correlation between Various Indices of Solar Activity and Solar Cycles....Pages 139-148 Front Matter....Pages 149-149 Caractères Météorologiques du Climat, et Activité Solaire: Quelques Remarques....Pages 151-160 A Suggested Approach to Research on the Sun-Weather Problem....Pages 161-167 Front Matter....Pages 169-169 Observations of Zodiacal Light in Egypt and Its Variations....Pages 171-182 On the Global Size of Oort’s Cloud of Cometary Nuclei and Their Total Number....Pages 183-190 Voyager Encounters with Jupiter’s Magnetosphere: Results of the Low Energy Charged Particle (LECP) Experiment....Pages 191-200 The Weather on Mars on the Basis of the Measurements Carried Out by the Vikings Mission....Pages 201-208 Front Matter....Pages 209-209 On the Origin of Nebulae....Pages 211-218 On Mass Loss from Stars....Pages 219-231 Contribution to Fourier Analysis of the Light Curves of Eclipsing Variables....Pages 233-245 Prospective Views in Space Astrometry....Pages 247-251 Long-Term Changes of the Flare Stars EV Lac and by Dra....Pages 253-276 On the Problem of Cepheid Amplitude Dependence on the Star Position in the Instability Strip....Pages 277-284 Early-Type Emission-Line Stars....Pages 285-293 Front Matter....Pages 295-295 The Structure of the Small Magellanic Cloud....Pages 297-313 Large Scale Distribution of Elements and Gravity....Pages 315-322 Active Galactic Nuclei and Particle Acceleration in Accretion Disks Around Massive Black Holes....Pages 323-345 Front Matter....Pages 347-347 Non Linear Einstein-Maxwell Differential Equations....Pages 349-359 Recent Results for the Moon’s Secular Acceleration and Their Implication for the Possible Variation of G in Dirac’s Large Number Hypothesis....Pages 361-366 Classical Phase Space from a Relativist’s Point of View....Pages 367-377 Front Matter....Pages 379-379 The Colonization of the Galaxy -- A Key Concept in the Search for Extraterrestrial Intelligence....Pages 381-390 Front Matter....Pages 391-391 Numerical Treatment of the Magnetohydrodynamic Flow Bounded by an Infinite Porous Plate....Pages 393-414 Ray Tracing and Caustics from Large Reflectors Used in Spacecrafts....Pages 415-445 Back Matter....Pages 447-464