From Babylon to the Big Bang

Peter Watson, whose lectures on astronomy a few years ago led us into the realm of quantum physics in a manner we could all understand, will present a unique two-part course on cosmology. The theme throughout will be our drive to understand how the universe works. The talks will follow the broad outline below, but topics may flow into the following time-slot

Part I: 6 Thursdays, beginning September 12, 2019, from 1:30 ~ 3:30 pm.

  1. The Birth of Astronomy: Stonehenge to Babylon. We will start with what we see in the sky, and why it presented such a problem to early cultures. The Mediterranean is not just the Cradle of Civilization, it is the cradle of astronomy. The Babylonians had the first Creation myth that we have recorded. They could predict eclipses, The Greeks not only knew the world was round 1500 years before Columbus, but even measured how big it was.
  2. The Birth of Astronomy: Greece and Alexandria. The Greeks even understood how the axis of the Earth changes over time, and could build complex computers to predict how the planets moved. Their discoveries culminated in Ptolemy’s Almagest: the first theory of the universe, one that lasted 1300 years.
  3. The Death of Astrology. For the whole of the Dark Ages, there was almost no new ideas in astronomy. But beginning with Copernicus all of the old ideas fell apart, to be replaced with a new view of the universe. Modern astronomy can be dated back to Jan 7th, 1608, when Galileo first looked at Jupiter with his new telescope. Seventy years later we knew how the solar system worked, and could even start imagining how big the universe was.
  4. Farewell to Earth. For thousands of years, people have speculated about leaving the earth, so nothing has caught the imagination like the exploration of the solar system. The first satellite was launched just 50 years ago: since then we have stood on the moon and looked out over utterly alien worlds.
  5. Comets and the Death of the Dinosaurs. The dinosaurs disappeared 70 million years ago. It seems almost certain that their demise was due to the collision of an asteroid with the earth. What is the evidence, could it happen again, and what else is there in the solar system?
  6. The Sun. All life on earth depends on the sun. What do we know about it? Has it actually changed over historical times, and can we predict how long it will last? And why did it provide a Nobel Prize for Canada in 2015?

Part II: 6 Thursdays, beginning October 24, 2019, from 1:30 ~ 3:30 pm.

This course will carry on where the first part left off. We will step out beyond the solar system, understand stars, galaxies and finally speculate about the universe itself

  1. Like humans, stars have a definite life-cycle, being born in stellar nurseries, going through an often tumultuous youth to respectable adulthood. Unlike humans, the death of stars in supernova is the most spectacular part of their life.
  2. Beeps, flashes, bangs and bursts. There are a variety of extraordinary objects out there. We more or less understand pulsars, which produce regular pulses of radiation, and even black holes have entered the popular imagination, but gamma-ray bursters, the most energetic objects in the universe defy explanation.
  3. Galaxies and beyond. Images of the great spiral galaxies are almost the best known symbol of astronomy. What are they like, and how did they get that way?
  4. Physics as a Creation Myth: How Big is it? Finding out how big the universe actually is has always been the most difficult problem for astronomers. For 150 years we have known it is not infinite in size, but it was one of the greatest triumphs of the 20th century to measure it properly and find it is actually growing.
  5. Physics as a Creation Myth: The Big Bang. Not only has the idea provided the genesis of one of the most popular sitcoms of all time, but it provides the benchmark for all our cosmology. The most disturbing discovery is the realization that most of the universe is not matter as we know it. Dark matter and dark energy are mysterious ideas floating around on the periphery of science.
  6. Beyond the Big Bang. We have been speculating about how the universe began and how it (and even whether) it will end. We can actually begin to answer some very profound philosophical questions, and even see many echoes of mythological ideas in recent theories of the universe.