How can astronomers determine the chemical composition of stars and galaxies that are millions to billions of light-years away, and how do they know that the universe is expanding? Students will use evidence to support the formation of the universe through the Big Bang.
Learning Objectives
- Understand the difference between a continuous, emission, and absorption spectrum.
- Identify elements by their emission and absorption spectral lines.
- Observe the Doppler effect for sound and apply that to the Doppler effect for light spectra.
- Model universe expansion, and then graph real data for given galaxies to calculate the age of the universe
What You’ll Need
Minds-on
- Construct an argument based on data and evidence
- Observe patterns
Use evidence to support the formation of the universe through the Big Bang theory in the classroom. Students collect pieces of evidence that each provide part of the story. They explore the spectra of different elements and light sources, analyze star spectrographs, investigate the Doppler effect for sound and light, model the expansion of the universe, and digitally observe the remnants of the Big Bang.
- What properties of stars, galaxies, and radiation in the universe have astronomers found that support the most accepted theory (the Big Bang) of how the universe began?
- How can astronomers determine the chemical composition of stars and galaxies that are millions to billions of light-years away, and how do they know that the universe is expanding?
For Students
- Students can tape a diffraction grating over their cell phone camera lens, and then take photos of spectra from different light sources.
- Have students do research on deep space probes used to measure and map the cosmic microwave background (CMB).
- Use a different methodology for measuring spectra of various light sources.
For Teachers
- Consider having students create a glossary in their notebooks.
- Investigation 1 can be used in chemistry for investigating wavelength and frequency in the electromagnetic spectrum.
- Investigations 2 and 3 can be used for understanding the Doppler effect for sound and light.