Paper to appear in Advanced Space Science. (astro-ph/9809410)

For a PDF version of the article, click here.

Table of Contents

• INTRODUCTION
• COSMOLOGICAL DISTANCE AND TIME
• GROWTH OF STRUCTURE IN THE BIG BANG COSMOLOGY
• The Cosmic Microwave Background
• Density Inhomogeneities in the Early Universe
• Non-Baryonic Dark Matter
• PROPERTIES OF PGs
• Surface Density
• Angular Size
• Luminosity
• Spectral Energy Distribution
• SEARCHES FOR PGs - AN HISTORICAL OVERVIEW
• Optical Continuum and Emission-Line Searches
• The Era of the Near-Infrared
• Masquerading PGs
• EVIDENCE FOR TYPE-DEPENDENT EVOLUTION OF GALAXIES
• The Lyman α Dropouts
• The Age of Elliptical Galaxies
• DUSTY ELLIPTICAL PGs
• CONCLUDING REMARKS AND FUTURE PROSPECTS
• REFERENCES