Frontiers/Controversies in Astrophysics (ASTR 160) Professor Bailyn introduces the course and discusses the course material and requirements. The three major topics that the course will cover are (1) exoplanets--planets around stars other than the Sun, (2) black holes--stars whose gravitational pull is so strong that even their own light rays cannot escape, and (3) cosmology--the study of the Universe as a whole. Class proper begins with a discussion on planetary orbits. A brief history of astronomy is also given and its major contributors over the centuries are introduced: Ptolemy, Galileo, Copernicus, Kepler, and Newton. 00:00 - Chapter 1. Introduction 05:38 - Chapter 2. Topics of the Course 12:57 - Chapter 3. Course Requirements 21:03 - Chapter 4. Planetary Orbits 31:32 - Chapter 5. From Newton's Laws of Motion to the Theory of Everything 38:10 - Chapter 6. The Newtonian Modification of Kepler's Third Law Complete course materials are available at the Open Yale Courses website: http://open.yale.edu/courses This course was recorded in Spring 2007.

When an unsuspecting star wanders too close to a supermassive black hole, the star can be ripped apart by the black hole's immense gravity. As the black hole messily feeds on the star, it produces an amazing display of light as bright as ten billion suns for many months. Using new surveys, astronomers are finding these hungry black holes throughout the Universe. Recently, it has been discovered that many years after feeding, these black holes sometimes produce a "heartbeat" of X-ray eruptions that repeat every several hours. Dr. Piro will describe some of the best theories to explain this mystery and what they can teach us about these enigmatic objects. Dr. Anthony Piro - Staff Scientist, Carnegie Science Observatories

List of referenced videos: Interactive Scale: http://htwins.net/scale2/ Video 1: The Scale of the Universe - https://youtu.be/nxs5wye0JXs Video 2: Asteroid Discovery - https://youtu.be/BKKg4lZ_o-Y Video 3: The Most Astounding Fact - https://youtu.be/9D05ej8u-gU Video 4: Understanding Simulated Universes - https://youtu.be/ZLlhVv4S1bs?t=27s Video 5: Why is the Milk Gone? - https://youtu.be/KjeKiIa7XEk Video 6: Pale Blue Dot - https://www.youtube.com/watch?v=RESsY2y8G2s