1. INTRODUCTION

DEFINITION: Cosmology is the study or the philosophy of the universe as an ordered whole.

• Our understanding of what "the Universe" is and our place within it has been assembled bit by bit from many separate discoveries going back to prehistoric times [EMPIRICAL]
• The interpretation and meaning attached to daily phenomena exhibited by objects within the Universe has varied enormously between different cultures [PHILOSOPHICAL/RELIGIOUS APPROACH]

The development of these two aspects of cosmology is best compartmentalised into 4 distinct eras:

1.

Prehistoric (before 500BC): establishment of the Earth, Sun, Moon, planets & stars as key elements of ``the Universe''. Recognisation of the cyclic nature of their motions $\rightarrow$ utilisation for time-keeping and predicting events. Explanation of this order via religious myths: finite and geocentric cosmos.

2.

Classical (500BC to AD1400): measurement and geometry established and applied to the heavens; idealised models constructed to explain cyclic motions. Demise of mythical explanations; geocentric view still prevailed.

3.

Renaissance (1400-1650): reassessment of geometrical models - recognisation that refinements were required. New models built on the complete ensemble of data accumulated over the centuries. Invention of the telescope - first major technological advance. Parts of the universe never seen before, now accessible. Birth of non-geocentric, scientific models.

4.

Modern (1650-present): the search for physical laws to explain the motions of heavenly bodies. Rapid development of technology: optics, electronics, computers & better mathematical techniques (calculus) revolutionised cosmology.

Of course, mythical/religious interpretations have nonetheless remained through to the present day!