Astronomy 141 - Life in the Universe - Autumn Quarter 2009

Welcome to the Astronomy 141 Lecture Podcasts. This is a brief message from me explaining the podcasts, and welcoming new and old listeners. University. Lectures will begin on Wednesday, 2009 Sept 23, and run through Friday, 2009 Dec 4. New lectures will appear shortly before 6pm US Eastern Time each day there is a regular class. Recorded live on 2009 Sep 23 in Room 1005 Smith Labo

A brief overview of the topics we will cover in Astronomy 141, setting the stage for how we can make a serious scientific inquiry out of the question of whether or not there is life elsewhere in the Universe. It is a short lecture, the first half was an overview of course mechanics (tests, homework, office hours, etc.) that I did not record. Recorded live on 2009 Sep 23 in Room 100

An introduction and review of the basic notation and physical units we will be using throughout this course. In particular, we will be using the Metric (SI) system for lengths, masses, times, and temperatures, and special astronomical units for distances (AU and Light Years) and masses (Earth Masses and Solar Masses) appropriate when discussing interplanetary and interstellar scale

What is the cultural history of our imaginings of other worlds and their possible inhabitants? I will draw examples from history, philosophy, literature, cinema, and popular culture. In the end, our imaginings about other worlds inform us more about ourselves, our hopes and our fears, than about extraterrestrial life. The scientific inquiry we are undertaking must therefore approac

Modern science was borne of an effort over many centuries to understand the motions of celestial bodies. The Copernican Revolution of the 16th and 17th centuries was the crucial moment in history when we finally understood the nature of celestial motions, and opened the door to the modern world. This lecture reviews the problem of celestial motions, the two competing models for exp

What is the nature of matter, and how did we come to understand the chemical elements and atomic structure? This lecture is a brief and selective overview of the history of our understanding of the nature of matter and chemistry. We will also introduce spectroscopy and radioactivity, two very powerful tools that came out of the chemical revolution that are crucial for the inquiry i

The geological revolution revealed that the Earth is of great antiquity and yet has a history we can read in the land. We will discuss ideas of cyclic and linear time, historical versus physical age estimates, the discovery of geological time, and radiometric dating methods that give us our present estimate of 4.54+/-0.05 Gyr for the age of the Earth. Recorded live on 2009 Sep 30 i

What is the nature of life? In this lecture I will review the revolution in biological thinking that has dramatically changed how we view life. I will review such persistent ancient ideas as spontaneous generation and why it took so long to disprove this notion, the impact of the microscope on biology, and the discovery of the laws and agency of heredity. This is obviously a highly

Cosmology is the study of the entire Universe as a physical system. The past century has witnessed a revolution in cosmological thought that has revealed the vastness of space and the depths of cosmic time, a revolution that is still playing out in the present day. The lecture will review the Earth's place in the Universe, the age of the Universe as reckoned by the time since the B

What is the interior structure of the Earth and how does it drive the Earth's magnetic and geologic activity? We will review our current knowledge of the interior of the Earth, how we measure it using Seismology, the origins of the Earth's magnetic field, and discuss the workings of plate tectonics. the Earth is a dynamic, geologically active world, which has interesting implicatio