Light and Dark

PREFACE 1 ESSENTIAL, USEFUL AND FRIVOLOUS LIGHT 1.1 Light for life 1.2 Wonder and worship 1.3 Artificial illumination 1.4 Light in art and entertainment 2 PATTERNS OF SUNLIGHT 2.1 The year 2.2 Equinoxes and eccentricity 2.3 The length of a day 2.4 The length of daylight 2.5 The length of a second 3 MONTHS AND MOONLIGHT 3.1 The lunar month and the lunar orbit 3.2 The lunar nodes and their rotation 3.3 The lunar day 3.4 The length of moonlight 3.5 Eclipses and Saros cycles 3.6 Tides 4 HISTORY, DATES AND TIMES 4.1 Solar calendars 4.2 The Roman Catholic Church and the development of astronomy 4.3 The start of the year 4.4 Lunar and other calendars 4.5 Time zones 4.6 The International Date Line 5 LIGHT AND THE ATMOSPHERE 5.1 Scattered light and twilight 5.2 Polarization of light 5.3 Rainbows 5.4 Cloudy skies 5.5 Halos 6 SEEING THE LIGHT 6.1 The human eye 6.2 Colour vision and colour blindness 6.3 Polarization sensitivity 6.4 Speed of response 6.5 Optical illusions 7 ZOOLOGICAL DIVERSIONS 7.1 Colour vision in animals 7.2 Zebras 7.3 Piebald coats and unusual goats 7.4 Jellicle cats are black and white 7.5 Cephalopods 17.6 Lighting up for a mate or a meal 7.7 More anatomical oddities 8 INFORMATION IN LIGHT 8.1 Lighthouses 8.2 Semaphores for optical telegraphy 8.3 Morse, Mance and the heliograph 8.4 Bell and the photophone 9 LIGHT IN THE ERA OF ELECTRONICS 9.1 Electronics 1900â"1960 9.2 New semiconductors for optoelectronics 9.3 Optoelectronic semiconductor devices 9.4 Bright light from cool solids 10 OPTICAL COMMUNICATION TODAY 10.1 Waveguides and optical fibres 10.2 The transparency of glass 110.3 Optical fibres 10.4 Optical amplification 10.5 Conveying sound by light 10.6 The long and the short of optical communication