Astronomy 1142: Black Holes
Autumn 2021

• Instructor: David Weinberg, Distinguished University Professor and Chair of Astronomy.
• Textbook: Black Holes and Time Warps: Einstein's Outrageous Legacy, by Kip Thorne.

• Course Syllabus.

Course Notes:

• Notes are in PDF format. I can provide a doulbe space version for anyone who wants more space to add their own notes.
• Part 1: Introduction, posted 8/22/21. Double-spaced.
• Part 2: Newton's Laws of Motion, posted 8/31/21.
• Part 3: Universal Gravity, posted 9/6/21.
• Part 4: Transition: EM Radiation, Momentum and Energy Conservation, Reference Frames. Reposted on 9/22/21 with an additional page describing the E=mc² thought experiment discussed in class.
• Part 5: Relativity. Posted 9/30/21. This is the final version, including material redacted from the originally posted notes.
• Part 6: General Relativity. Posted 9/30/21.
• Part 7: Stellar Death and Black Hole Birth. Posted 10/18/21.
• Part 8: Digression on angular size, resolution, spectra. Posted 10/25/21.
• Part 9: Stellar mass black holes. Posted 10/25/21.
• Part 10: Supermassive black holes. Posted 11/3/21. Revised version (corresponding more closely to what I presented in class) posted 11/15/21.
• Part 11: Gravitational Waves. Posted 11/17/21.
• Part 12: Imaging black holes. Posted 11/29/21.
• Part 13: Black hole evaporation. Posted 12/3/21.

Slides from lectures:

• Introduction: pdf or pptx.
• Isaac Newton
• Kepler's laws (9/10/21).
• Jupiter and Saturn orbits, pdf or pptx.
• Summary of evidence for Newton's theory of gravity, pdf or pptx.
• Special relativity slides (9/24/21), pdf or pptx.
• Einstein's 1911 paper on the influence of gravity on light (10/8/21), pdf or pptx.
• Empirical evidence for GR (10/11/21), pdf or pptx.
• Stars and spectra (accompanying sections 7 and 8), pdf or pptx (10/20/21).
• Class Questions 13: Angular sizes (10/22/21).
• Class Questions 14: Mass of the Milky Way black hole (10/25/21).
• Stellar mass black holes (accompanying section 9) pptx or pdf (10/27/21).
• Quasars and radio galaxies (accompanying section 10) pptx or pdf
• Gravitational waves (accompanying section 11) pptx or pdf (11/22/21).
• Imaging black holes (accompanying section 12) pptx or pdf (11/29/21).
• Questions asked on Day 1.

Homework assignments:

• Homework assignment 1, due Friday, 9/17. Solutions handed out on Monday, 9/24.
• Homework assignment 2, due Friday, 10/1. Solutions handed out on Friday, 10/8.
• Homework assignment 3, due Friday, 11/5. Solutions handed out on Wednesday, 11/17.
• Optional extra credit assignment, due Monday, 11/29.
• Homework assignment 4, due Friday, 12/3. Solutions handed out on Monday, 12/6.

Information sheets:

• Manipulating equations. To help you remember some rules of algebra that you might have forgotten.
• Scientific notation.. Some reminders on scientific notation and test problems to check that you can use it correctly on your calculator.
• First few pages of Einstein's 1905 paper On the Electrodynamics of Moving Bodies.
• Review Guide for the midterm exam.
• Solutions to the midterm exam were handed out on 10/18 together with the graded midterms.
• X-ray Iron Lines from a Black Hole Accretion Disk, handout for the 11/3/21 in-class question.
• Review Guide for the final exam. Includes course evaluation questionnare.
• Compilation of in-class questions asked during the semester.

Videos or images shown in class:

• Earth orbiting a black hole, an animation by Andrew Hamilton.
• Stars orbiting the Milky Way black hole.
• Relativity of simultaneity.
• Time dilation.
• Time dilation experiment. Follows a re-creation of the 1970 clocks-on-airplanes test of time dilation.
• Shoot-the-monkey illustration of the equivalence principle.
• Einstein's elevator, a simple demonstration that objects travel on straight paths in a freely falling reference frame.
• Weightlessness in the International Space Station
• Sound of a pulsar. The image shows the Vela supernova remnant, and the sound is a translation of the central pulsar's pulsating radio signal into sound.
• Space Time Animation. A bit odd, but the animation in the second half is pretty good.
• A new way to visualize General Relativity. This video proposes an alternative to the conventional "rubber sheet" visualization of curved spacetime, one that better represents what is going on in GR. Suggested to me by A1142 student Tim Browning.
• Visual summary of GR. This video, by the same animator is the one above, covers GR more broadly, from the equivalence principle to black holes.
• Now a set of items related to LIGO and gravitational wave detection; these and others can be found at this LIGO website
  • Kip Thorne interview on gravitational waves"
  • The journey of a gravitational wave discovered by LIGO in 2015.
  • Interferometer response to a gravitational wave
  • Black hole merger ripples in a spacetime pond
  • Gravitational wave chirp
  • Simultaneous gravitational and electromagnetic detection of a neutron star merger
  • LIGO signal from a binary neutron star merger
• Inspiral calculation for a supermassive black hole. This video shows the predicted orbit of a stellar mass black hole orbiting a spinning supermassive black hole and eventually merging. This kind of event should be detectable with LISA, but not with LIGO.
• Similar inspiral calculation for a supermassive black hole; this movie stops at several points and shows you the patterns.
• BBC video clip on Hawking radiation. I showed a few of minutes of this 7-minute video in class. While this video is generally good, if you aren't careful you will come away with the very incorrect impression that Hawking radiation is what we see when we observe distant black holes, whereas what we see is actually emission from accreting gas outside the event horizon.
• Black hole waterfall description from Andrew Hamilton's Inside Black Holes web site.

Other links, some to videos, some to informational web sites or images:

• Death by black hole.
  A conversation with the always-entertaining Neil DeGrasse Tyson.
• A journey into a black hole. This 7-minute video has quite good (and carefully calculated) visualizations and narration explaining what is going on.
• The Black Hole. Not what they are really like.`
• Frames of Reference. I vividly remember this science film from high school physics class; even then it was comically retro. Someone has broken it into chunks and posted it to YouTube. We watched the first 3 minutes of Part 1 in class. Part 3 is my favorite.
  Part 1.
  Part 2.
  Part 3.
  Part 4.
  
• A Slower Speed of Light Trailer for a (downloadable) video game that illustrates relativity by steadily slowing the speed of light.
• Kip Thorne interview on spacetime (14 mins).
• Scenes and interviews on the first LIGO discovery (3 mins)
• The article from the LIGO team on the first gravitational wave discovery.
• Fuzzballs. A (16-minute) video discussing the black hole information paradox and the proposed solution based on string theory ``fuzzballs'' from OSU Physics professor Samir Mathur. This is an advanced topick, but the explanation in this video is very good, and accurate.

Links to videos available for in-class question replacement assignments

• Interstellar Monthly Movie Night Panel.
• Black Holes and Beyond, interview with OSU Professor Smita Mathur, in OSU Astronomy's Making Space for All series.
• Supernovae: The Secrets of Exploding Stars, interview with OSU Professor Laura Lopez, in OSU Astronomy's Making Space for All series.