15: The Cosmic Microwave Background
- Page ID
- 30492
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)
Chapter 15 describes the observations and our understanding of the Cosmic Microwave Background (CMB), arguably the most important evidence that supports Big Bang theory. CMB observations are described in detail, including the measurements of the tiny variations in temperature that are the seeds of structure formation. The chapter concludes with a comparison of the CMB observational data to predictions made by varying models of the Universe.
- 15.0: The Cosmic Microwave Background Introduction
- Since its discovery in 1965, the cosmic microwave background (CMB) has provided some of the most important observational constraints for our theories of the nature and evolution of the Universe. The CMB is a glow of microwave light coming from every direction in the sky. Together with the abundances of the lightest elements and the Hubble expansion, it is one of the key observational pillars supporting the Big Bang theory.
- 15.1: Observations of the CMB Spectrum
- You will know that the CMB is nearly uniform and coming from all directions. You will know that the CMB spectrum is a 3K blackbody
- 15.2: Implications of the CMB Temperature and Spectrum
- You will understand why the CMB supports the Big Bang Theory.
- 15.3: Observations of Variations in the CMB
- You will understand what the spots are on CMB anisotropy maps. You will understand how CMB measurements are made.
- 15.4: Understanding the Variations in the CMB
- You will understand why the universe became transparent when the CMB formed. You will understand acoustic oscillations
- 15.5: Comparing Models and Data - The CMB and the Curvature of Space
- You will be able to compare models for the effect of the curvature of the Universe on CMB maps and power spectra and choose which one best fits the data
- 15.6: Wrapping It Up 15 - Using CMB Data to Determine Cosmological Parameters
- You will be able to use CMB anisotropy power spectra to compare to data with models and determine parameters (baryon fraction, cold dark matter, curvature) to demonstrate their understanding of how models compare with data. Parameters will be adjusted individually rather than jointly in this activity. You will further explore the telescopes used to study the CMB.
- 15.7: Mission Report 15: Using CMB Data to Determine Cosmological Parameters
- You will be able to use CMB anisotropy power spectra to compare to data with models and determine parameters (baryon fraction, cold dark matter, curvature) to demonstrate their understanding of how models compare with data. Parameters will be adjusted individually rather than jointly in this activity. You will further explore the telescopes used to study the CMB. You will use galaxy survey data to explore some typical objects and a 3D map of the Universe.