Unit 11: Dark Energy
© NASA.
Unit Overview
This unit focuses on one of the biggest questions in 21st century physics: what is the fate of the universe? In recent years, astronomers have been surprised to discover that the expansion of the universe is speeding up. We attribute this to the influence of a "dark energy" that may have its origin in the microscopic properties of space itself. Even very simple questions about dark energy, like "has there always been the same amount?" are very difficult to answer. Observers are inventing programs to provide fresh clues to the nature of dark energy. Theorists hope to come up with a good new idea about gravity that will help us understand what we are seeing in the expansion that causes the acceleration of the universe. Astronomers can observe the past but can only predict the future: if dark energy takes the simplest form we can think of, the universe will expand faster and faster, leaving our galaxy in a dark, cold, lonely place.
Content for This Unit
Video
Visuals
Scientists
Interactive Lab
Facilitator's Guide
Glossary
Online Text
by Robert Kirshner
Sections:
- Introduction
- Before the Beginning: A Static Universe
- Discovery of the Expanding Universe
- Mapping the Expansion with Exploding Stars
- Beyond Hubble's Law
- The Concept of Dark Energy
- From Deceleration to Acceleration
- Dark Energy Theory
- Further Studies of Dark Energy
- Further Reading
- Printable Online Text for This Unit (PDF)
