15.0 Learning Objectives

In this chapter, students will learn how to:

• Summarize the process of how astronomers measured the spectra of galaxies and explain how the redshift phenomenon led to the discovery of the expanding universe.
• Calculate the age of the universe based on measurements of galaxy distances and velocities, applying the Hubble constant concept.
• Evaluate the evidence and reasons behind astronomers’ conclusions about the fate of the universe, considering factors like density, dark energy, and the observed acceleration of expansion.
• Explain the concept of Cosmic Microwave Background (CMB) radiation and its significance in supporting the Big Bang theory.
• Identify the key components of the standard model of cosmology, including the assumptions, observations, and supporting evidence.
• Describe the composition of the universe, distinguishing between luminous matter, dark matter, and dark energy, and how they contribute to the critical density.