Classroom Discussion Activity

Gravity: Making Waves

Gravity may seem elementary. But proving Einstein’s theories about it is quite hard. To do so, scientists are struggling to capture gravity’s most elusive hallmark: the gravitational wave. This Astro Feature focuses on research at the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Livingston, LA, where scientists have constructed a sprawling facility dedicated to the detection of minute changes in spacetime caused by gravitational waves traveling from energetic events in space.

Class Discussion

Establish prior Knowledge
Discuss gravity with your students. What did Newton discover about gravity? What was Einstein’s theory about gravity? You may want to refer them to the essay: Newton vs. Einstein vs. the Next Wave ( for a discussion of the two scientists’ theories about gravity. (See page 2 for a description of What is a Theory?”) Tell them that the video they are about to see shows scientists testing Einstein’s theory of gravitational waves.

Have students watch the video. Use the following questions to guide a class discussion.
• What are gravitational waves?
• What have scientists theorized so far about gravitational waves?
• Why is learning about gravitational waves important?
• How do scientists hope to measure gravitational waves?
• How is the study of gravitational waves helping scientists to understand the forces that shape our universe?

Use the following questions to wrap-up your discussion:
• What had Newton theorized about, but was unable to prove or provide data for?
• How did Einstein refine and further explain theories that Newton could only hypothesize about?
• How does this demonstrate the dynamic nature of scientific understanding?

Students who wish to learn more can visit these related links from NASA:
NASA puts einstein to the test
LIGO isn’t the only project searching for answers about gravity. See how scientists are using the satellite, Gravity Probe B, to learn about the gravity waves around our planet.
Amazing GRACE
How does gravity affect our atmosphere? NASA’s Gravity Recovery and Climate Experiment (GRACE) project is seeking to collect information abouton the impact of Earth’s gravity about our climate systems.
Laser Interferometer Space Antenna: Education
Explore the topic of gravity with your students through articles, games, and a science bowl quiz.
Ask a High-Energy Astronomer: Relativity
This page features answers to commonly asked questions about space-time, gravity, and relativity