Lesson plan: Theories of universe

RELATED SITES

Objectives

Students will:

• Observe and draw a model for universe expansion.
  
• Make connections between the big bang theory and current satellite data.

Standards

Benchmarks for Science Literacy

By the end of the 12th grade, students should know that

• On the basis of scientific evidence, the universe is estimated to be more than 10 billion years old. The current theory is that its entire contents expanded explosively from a hot, dense, chaotic mass.
• Increasingly sophisticated technology is used to learn about the universe. Visual, radio and X-ray telescopes collect information from across the entire spectrum of electromagnetic waves; computers handle an avalanche of data and increasingly complicated computations to interpret them; space probes send back data and materials from the remote parts of the solar system; and accelerators give subatomic particles energies that simulate conditions in the stars and in the early history of the universe before stars formed.

National Science Education Standards

• The origin of the universe remains one of the greatest questions in science. The big bang theory places the origin between 10 and 20 billion years ago, when the universe began in a hot dense state; according to this theory, the universe has been expanding ever since.

Materials

Time

1-2 class periods, 45 minutes each.

Procedures

1. Ask your students what they know about the big bang theory.

2. Have students theorize how matter might have arrived at where it is now after that event.

3. Ask students: If the big bang was an explosion in all directions, then in what direction is all matter moving now (related to the point of the big bang)?

4. Have students read the CNNfyi article "Telescope reveals early universe" and ask the following questions:

• What shape do scientists think the universe forms?
• How have they arrived at that conclusion?
• Do you agree with the notion that there could be perpetual (infinite) expansion?
• What device helped solidify this data? What prior evidence did it support?

5. Have an in-class demonstration. Drop a small stone into a large sink or tank. Have students observe and draw the ripples as they go away from the center.

6. Have students explain how fast the ripples moved at first and then at a later point.

7. Have students explain the size of the circle formed by concentric ripples in all directions and estimate the diameter of at least three ripples.

8. Ask students: What happens to the diameter of the circular ripples as they move away from the center? What happens to the speed of the ripples as they move away from the center?

9. Relate the ripples in the tank to the big bang theory and the current data about the universe. Tell students that, according to the theory, there are microwaves given off as the matter spreads outward. These microwaves keep getting longer as they go away from their central source. Explain that by using the length of the microwaves and the rate of their elongation -- just like the rate of the movement of the waves and their elongation -- scientists were able to infer the age of the universe and support their theory that the universe is flat.

Evaluation

Either for homework or as a follow-up on the day after their observation, have students draw what they think the microwaves would look like if they could become visible and have them explain how they indicate the shape of the universe.