How Old is the Universe?

The title question about the age of our universe poses a deceptively simple question, and its answer carries profound implications for science, religion and philosophy. In this class, we will trace the centuries-old quest by astronomers to fathom the secrets of the nighttime sky. We will discover how they have used their knowledge of astrophysics and their observations of the heavens to determine that the universe is 13.7 billion years old. By the end of the course, you will understand why astronomers know this is the answer to the title question. Individual classes will focus on 1) ancient answers for the age of the universe, Renaissance science's impact on that ancient wisdom, and Biblical Chronology as a reasonable seventeenth century response to the birth of modern science; 2) nineteenth-century discoveries that changed astronomy into astrophysics; 3) white dwarf stars as a chronometer for the age of the universe; 4) star clusters as another tool for measuring the age of the universe; 5) the expanding universe as a third method for dating the universe; 6) maps of the cosmic background radiation, dark matter and dark energy as a fourth method for determining the age of the universe. No background in math, astronomy, or physics is required to understand this material.

David A. Weintraub is professor of astronomy, director of the Communication of Science & Technology program, and director of Undergraduate Studies for Department of Physics & Astronomy at Vanderbilt University.

1. Ancient Answers for the Age of the Universe
2. Nineteenth-century Discoveries that Changed Astronomy into Astrophysics
3. White Dwarf Stars as a Chronometer for the Age of the Universe
4. Star Clusters as Another Tool for Measuring the Age of the Universe
5. The Expanding Universe as a Third Method for Dating the Universe
6. Maps of the Cosmic Background Radiation, Dark Matter and Dark Energy

Related Links
The Age of the Universe
Detailed observations of galaxies, clusters, and the fine structures in the cosmic microwave background have refined the age of the Universe to 13.75 billion years. But they have also revealed the unexpected presence of dark energy, causing a huge paradigm shift in modern cosmology.
Cosmos: A Personal Voyage
This is a thirteen-part documentary series written by Carl Sagan, Ann Druyan, and Steven Soter, with Sagan as presenter.
The Cosmos: A Beginner's Guide
This is a BBC documentary series presented by Adam Hart-Davis, offering an introductory look at the world beyond us.
Hunting the Edge of Space
This is a two-part PBS documentary examining how a simple instrument, the telescope, has fundamentally changed our understanding of our place in the universe.
Stephen Hawking's Universe
This is an astronomical documentary series, presented by Stephen Hawking, discussing the history of astronomy, origins of the universe, dark matter and black holes.
Cosmic Origins
Cosmic Origins is the story of the universe but it's also our story. Hear about origin of space and time, mass and energy, the atoms in our bodies, the compact objects where matter can end up, and the planets and moons where life may flourish.
During this course, you'll have the opportunity to study the cosmos from the modern perspective - what we know and what we're not sure about.