THE SUN: SOURCE OF ENERGY AND LIFE

THE SUN: SOURCE OF ENERGY AND LIFE The sun is only one the thousands of stars found in our Galaxy. Physical characteristics of the Sun: size, distance, mass, temperature,... The Sun’s energy: its main chemical element is Hydrogen. Helium atoms. Nuclear fusion. The Seas. The Sun and life: Whereas plants use the Sun’s energy directly, man uses the same energy in different ways. Summary. INTRODUCTION - The Sun is only one of the thousands of millions of stars which are spread out over our galaxy. - Characteristics of the Sun: its weigh, mass, dimension, temperature. - Importance of the Sun for the Earth. THE SUN’S ENERGY - Composition of the Sun - The Sun shine - Nuclear fusion THE SUN AND THE EARTH - The solar radiation - The Aurora Borealis - The Earth absorbs only part of the solar radiation - The marine currents. - The marine winds. - Water-vapour clouds in form of rain. - The water-cycle THE SUN AND LIFE - The Plant Kingdom is the only one capable of taking direct advantage of the Sun’s energy. - The photosynthesis - Mankind receives chemical energy through the food he eats. - Winds, water and the kinetic energy. - Energy problems SUMMARY