Boundaries of the Universe

6. Distance in Astronomy

 

Astronomy is the science of vast distances, of the ultra-large taking in as it does the furthermost corners of all existence. For long ages, however, it was based solely on what the eye could see and, although this method of observation works efficiently in many cases, for example in the charting of the constellations and the movements of the Sun, Moon and planets across the heavens, it can often lead us into serious error. This is perhaps nowhere more obvious than in the illusion, which persisted from the earliest times to the end of the Middle Ages, that the stars were all at the same distance from us, mere specks of light on an inverted bowl. It is not difficult to understand how this illusion came about. The human ...