Talk #3, 4/1/03


Bob Ginaven

For countless thousands of years mankind has gazed upward at the night sky and wondered…

  • How big is the universe?
  • How many stars are there?
  • What force holds the stars “up there”?
  • Has the universe always been here or did it have a definite beginning?
  • If it had a definite beginning how old is it?
  • What will eventually happen to the universe and when?


In the last one hundred years tremendous progress has been made in our observation and understanding of our universe. This talk is a review of the major discoveries and the theories (or models) that they support.

Some of the topics covered include:

  • The expanding Universe and the Big Bang Theory
  • Hubble’s Law
  • The discovery of the Cosmic Microwave Background (CMB)
  • The age of the universe
  • Supernova measurements and the accelerating universe
  • Fluctuations in the CMB giving a picture of the early universe (see figure 1)
  • Structure and matter in the universe; dark matter and dark energy
  • Modification of the Big Bang Theory – Inflation


As more space-based instruments are implemented our knowledge of the universe will undoubtedly continue to increase at a mind-boggling rate. This talk is intended to give interested people an introduction to the terminology of cosmology and a basis for some understanding of new discoveries and theories.