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Artist's depiction of an exoplanetary system, SSC Astronomy 141:
Life in the Universe
Prof. Richard Pogge, MTWThF 12:30

Unit 2: Five Revolutions

Why is Astrobiology only now becoming a real, serious scientific inquiry in the early 21st century? This unit will review five scientific revolutions that have set the stage for us to start seriously addressing the question of life on other worlds for the first time in human history. Along the way, I will use these lectures to illustrate how science works and helps give us the necessary intellectual framework in which to pose answerable questions and interpret the answers. This forms the essential background for the rest of the course.


The lecture notes below are in Adobe PDF format, and the accompanying audio recordings are in MP3 format.
The Copernican Revolution (Jan 6) - [Audio]

The Chemical Revolution: The Nature of Matter (Jan 9) - [Audio]

The Geological Revolution: Deep Time and the Age of the Earth (Jan 10) - [Audio]

The Biological Revolution: What is Life? (Jan 11) - [Audio]

The Cosmological Revolution: The Depths of Space and Time (Jan 12) - [Audio]

Lectures will be posted on the morning before class, or earlier if I get ahead of things. Please also see A Note about Graphics to learn why some of the graphics shown in the lectures are not reproduced in these notes.

Supplemental Readings

All readings for this unit should be viewed as supplemental: I am taking a different approach from the book, as I feel it is as important to understand how we came by our modern view of the world as what that view is. I'm setting the stage for later sections where we will dive right into the modern state of knowledge. All readings are from various sections of Chapters 2 to 4 in the 3rd Edition of Life in the Universe. Not all topics covered in this unit are covered in the book, or covered in the same way, so these readings jump around a lot more than they will in other units.

If you have a copy of the 2nd edition of Life in the Universe, the section headings are the same but the page numbers are different (and there are a few different graphics, but they are differences without a substantive distinction - mostly more colorful or slightly more "artsy" in the 3rd edition).

The Copernican Revolution
Sections 2.1 or 2.2. This covers ancient Greek astronomy and the Copernican Revolution.

The Chemical Revolution
Section 3.4, while my lecture emphasizes more the history of our thinking about matter, this reading will give you a reasonable a general overview of the subject, and review the basic vocabulary of atoms and molecules.

The Geological Revolution
Section 4.2, pages 108-112 on radiometric dating and the age of the Earth. Again I take an historical approach to see the changes in our thinking that had to occur for the radiometric result to make sense, the book interleaves the discussion of these topics in the larger context of the history of the Earth which we'll touch on again later.

The Biological Revolution
There is no corresponding reading - the book mostly focuses on Darwin and Natural Selection which we'll deal with more later.

The Cosmological Revolution
Section 3.1 and 3.2 give another view of this, again less from the historical perspective adopted in this unit. Should make good supplemental reading, but I won't be going into this kind of detail (this section of the book is highly compressed).

[ Return to the Astronomy 141 Main Page | Go forward to Unit 3 | Go back to Unit 1 ]
Updated: 2012 January 12
Copyright © Richard W. Pogge, All Rights Reserved.