Abstract

The Universe is now about 15 billion years old. As a result of its advancing years, it is mature, subtle and very interesting. In its youth, however, it was far more brash, volatile and exciting. By looking out deep into the Universe, one is also looking backwards in time, since the light from its distant parts has taken billions of years to reach us. One can therefore learn about the Universe’s childhood, and discover the events that shaped the adult we know today. This is the study of cosmology, which has some big questions to answer. How did the Universe begin? What is the origin of all the structure we observe in the Universe today? What is the Universe made of? What is its future? In recent years, considerable progress has been made in providing some answers. In particular, observations of anisotropies in the cosmic microwave background has been very informative. This `afterglow’ of the Big Bang is the oldest light in the Universe and has provided a snapshot of the Universe as a youngster. Examining this picture closely has allowed us to understand its development into adulthood and predict whether or not it will grow old gracefully.