13: The Expansion of the Universe
- Page ID
- 30490
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Chapter 13 presents the observational evidence for the expansion and age of the Universe and the basis of the Big Bang theory. The chapter begins by presenting some historical background that sets the context for understanding Edwin Hubble’s observation that the Universe is expanding. You will determine the expansion rate, and then, using Hubble’s Law, learn how to estimate the age of the Universe. The last section of the chapter introduces Big Bang theory; exploring properties of the expansion, including changes in density and temperature.
- 13.0: The Expansion of the Universe Introduction
- In this chapter we will begin our investigation of an expanding Universe. In particular, we will look at the evidence that causes scientists to think that the Universe is expanding. We will see how an expanding Universe implies that at some time in the past everything we see around us must have been extremely close together, and we will learn how to calculate when that was. The stretching history we see is consistent with the predictions of general relativity, our key physical theory
- 13.1: Some History
- You will understand some context for our place in the Universe according to Western traditions.
- 13.2: The Hubble Law
- You will be able to construct and interpret a Hubble diagram from the distances and velocities of galaxies. You will be able to perform calculations and understand the Hubble law conceptually.
- 13.3: The Universe is Expanding
- You will know that the Hubble law is evidence that the Universe is expanding. You will know that the Universe is expanding but not individual galaxies. You will know that there is no center or edge of the Universe.
- 13.4: The Age of the Universe
- You will be able to perform calculations and understand conceptually the relationship between the expansion rate and age of the Universe. You will be able to distinguish the concepts of Universe and observable Universe.
- 13.5: The Basic Big Bang Model
- You will know that the Big Bang theory features an expansion of space not an explosion of matter. You will know that the expansion of the Universe can be described by general relativity. You will know that the expansion leads to a change in the Universe over time, including temperature and density.
- 13.6: Wrapping It Up 13 - How Well Do We Know the Expansion Rate and Age of the Universe?
- You will be able to put everything together to demonstrate your understanding of the expansion and age of the Universe, including determining the accuracy of your measurements for these two important parameters.