Study Guide – The Big Bang II.

Model Seminars Program

Readings:

Foundational text:

Penzias and Wilson, A measurement of excess antenna
temperature at 4080 Mc/s

Additional reading:

Alan Lightman, The Discoveries

Section 19 – Radio waves from the Big Bang

Requirements:

Read the above readings before the seminar, and prepare responses to the questions below. I suggest that you first take a look at the foundational text. Then look through the questions below, and then read the Additional Reading material paying special attention to finding the answers to the questions. Once you have a better understanding of the material, revisit the Foundational Text, this time more carefully, and look for the answers for the related questions.

You will be required to turn in your responses to the questions. The study guide will be graded for completion.

Besides your responses, please bring the printouts of the Foundational Text and Additional Reading with you to seminar.

Note1: The covered textis often complex and may include terms you are not familiar with. While some may be critical to understand the big picture, you will not need to understand all the terminology or all paragraphs to grasp the major points in the text and be able to answer the questions. If you find that a term is not explained but seems to be critical to following the text, try to look for a more detailed definition online.

Note 2:I encourage you to work in groups on understanding the text and preparing responses. This will make your preparation easier and more fun, and you will understand the material more effectively through discussing the topics in a group setting.

Questions:

Prepare answers for the following questions, related to the two readings. We will discuss some of these questions during the seminar. Be prepared to defend your response through reasoning or by, e.g., referring to specific parts of the reading.

THE COSMIC BACKGROUND RADIATION

(Lightman Sec. 19)

  1. What did Penzias and Wilson intend to measure with their horn-reflector antenna? Is this related to their discovery?
  1. Penzias and Wilson did not publish their discovery right away. What was the reason for the delay? What did eventually change their minds?
  1. Penzias and Wilson were not the first to discover the background radiation. Why was it not appreciated earlier?
  1. Where does the measured cosmic background radiation originate? What does it tell us about the conditions in the early Universe?
  1. What was Dicke’s and his colleagues’ expectation of the long-term evolution of the Universe? What was their reasoning?

A MEASUREMENT OF EXCESS ANTENNA TEMPERATURE AT 4080 MC/S

  1. Do the authors discuss the implication of their finding? Why or why not?
  1. What did the authors use as ‘control’ in their measurement?
  1. What are the random and systematic uncertainties in the presented analysis?

+1. What questions do these results leave open? What could be a next experiment that could answer this question?