Lesson Plan Overview & Details

Overview:

In this module, students will learn about the "Big Bang" theory of the birth and expansion of the universe, the Hubble constant, and the use of Cepheid variable stars to calculate the distance to other galaxies. They will be introduced to these concepts by visiting a number of sites on the World Wide Web where these concepts and others will be explained.
To enhance their understanding of these concepts, students will perform two hands-on investigations and one computer simulation. The first investigation is a visualization of expansion of space in which the students will calculate the age of the universe. Next, students will download a computer program which simulates the functions of an observatory to measure the spectra of distant galaxies. Finally, the students (or you) will download and use Hubble Space Telescope data to plot and calculate the period of a Cephiad variable star in the M100 galaxy. Using the calculated distance to this star, students will calculate the Hubble constant.

• Subjects:
  Astronomy
  Physics
  Cosmology
  Earth Science
  
  
• Concepts:
  The "Big Bang" cosmological model
  Expansion of the universe
  The Hubble constant
  "Standard candles", with emphasis on cepheid variable stars
  The age of the universe
  
  
• Process Skills:
  Experimenting
  Graphing
  Calculating
  Observing
  Analyzing
  
  
• Execution Time
  Approximately six (45 minutes) class periods
  
  
• Field Tested
  This lesson has been field tested one time by the author

Details:

• Desired Learning Outcomes
  Students will be able to demonstrate an understanding of how the universe is expanding.
  Students will be able to use online data to determine the period of a Cephiad variable star.
  Students will be able to calculate the Hubble constant.

• Prerequisites:
  Keyboard skills, navigating the World Wide Web
  Understand the electromagnetic spectrum and frequencies of radiation
  Understand the structure of the atom and the Kelvin temperature scale

• New Vocabulary:
  absolute magnitude
  absorption spectrum
  apparent magnitude
  Big Bang Model
  cepheid variable stars
  cosmic microwave background
  cosmology
  Doppler effect
  electromagnetic radiation
  electromagnetic spectrum
  Hubble constant
  inverse-square law
  light year
  magnitude
  photometry
  photon
  primeval fireball
  radial velocity
  redshift
  standard candle

• Preparation time:
  60 Minutes for the teacher to read through the web site, the offline labs, and to download and photocopy lab materials.
  Optional 60 minutes for the teacher to download the entire web site and load it onto a computer network.

• Execution time:
  Six (45 minutes) class periods. The first, third, and fifth spent visiting the web site, the second, fourth,and sixth performing offline lab exercises.

• Materials required:
  This is a computer-based lesson. Students will need computers and internet access. For schools with limited internet access, the entire site may be downloaded using WebWhacker or similar software and loaded into offline computers.
  Students could work individually, as part of a small group around one computer, or as part of a large-group lesson if projection capabilities are available.