Astro 105 Summer 2026

             The Stars and Galaxies

             IU Indianapolis

                    bwoodahl@iu.edu

                    (Don't Use Canvas Messages to contact me, use email link)

                    Office: LD 156-S, 278-9244

                    http://woodahl.physics.indianapolis.iu.edu/Astro105Summer/

Week 1 (May 18 - May 22) Video Lectures and Images

• "Introduction to the Sun" #1 Video Lecture

• The Big Picture (actually it's a somewhat small picture)

• Examples of Some Big Numbers

• Astronomy, the Oldest of the Sciences, 5000 Years Old: Stonehenge

• Approaching Modernity: Galileo Galilei's 1610 AD Notebook Page (Who Needs Computers?)

• Our Sun (oh was it angry when we took its picture)

• Temperature: Simply a Measurement of Particle Velocity

• "Kelvin & Helmholtz Theory, Sun's Exterior" #2 Video Lecture

• Authors of the ill-fated: chemical reactions due to gravitational collapse theory, of Kelvin and Helmholtz

• Sunspot Formations

• Magnetic Field Lines Trap Moving Charged Particles (Thus They Spiral)

• Solar Prominences (Filaments)

• Solar Flare

• Coronal Mass Ejection (Orange Disc is Photosphere, Red Disc is Chromosphere, X-Ray Photography)

• "Proton-Proton Chain" #3 Video Lecture

• Atoms: The Building Blocks of Nature

• Water Molecule: Two Hydrogen Atoms and One Oxygen Atom

• The 4 Fundamental Interactions (Forces)

• The 4 Fundamental Forces Occur Only at Moderately Low Temperatures

• Nuclear Reactions: Fission and Fusion

• Sun's Proton-Proton Chain Fusion Reaction (4 Protons Produce Helium + Energy)

• Details of the Proton-Proton Chain

• Proton-Proton Chain in Action

• Sun In Hydrostatic Equilibrium

• "The Solar Neutrino Problem" #4 Video Lecture

• Sun's Inner Structure (Layers Not Necessarily To Scale)

• Neutrino (Artistic Rendition)

• Homestake Neutrino Detector in South Dakota

• Ray Davis, 2002 Nobel Prize in Physics for the Detection of Cosmic Neutrinos During 1960's

• Quarks Fundamental Particles, Three Quarks in Every Proton and Neutron

• "The Physics of Light" #5 Video Lecture

• Einstein (in 1904): Speed Of Light is the "Speed Limit of Our Universe"

• Light Waves Possess Wavelength and Frequency

• Visible Light is a Small Part of the Entire Electromagnetic Spectrum

• Isaac Newton (in 1670): White Light Contains All the Visible Colors (Visible Frequencies)

• Duality of Light: Light Is Both a Wave and a Particle

• Wave Aspect of Light: Young's Interference Patterns

• Particle Aspect of Light: Einstein's Photoelectric Effect

• James Maxwell (in 1860): Father of the Famous Maxwell Equations Governing the Behavior of Light

• Blackbody Radiators Produce Signature Intensity Profiles

• Wilhelm Wien (in 1893): Developed Theory (Wien's Law) for the Brightest Color of a Blackbody Radiator

Week 2 (May 25 - May 29) Video Lectures and Images

• "Spectra and the Doppler Effect" #6 Video Lecture

• Spectra of Helium, Sodium, and Neon

• Absorption Spectra

• Niels Bohr (sitting with Einstein): Architect of Modern Theory of Atomic Physics

• Photon (wavy line) Being Absorbed by Atom -> Electron (solid blue line) Jumps Up into Higher Orbit

• Atom Emitting a Photon (wavy line) -> Electron (solid blue line) Jumps Down into Lower Orbit

• Sound Produced by Stationary Source

• Sound Produced by Moving Source: Doppler Effect

• Doppler Effect on Spectra: Redshifting and Blueshifting

• "Parallax Formula and Surface Temperatures" #7 Video Lecture

• Our Visible Universe is Home to 10²² Stars

• Proxima Centauri

• Stellar Parallax: Determines Distance to Nearby Stars

• Stars with Higher Surface Temperatures Emit Mostly Shorter Wavelengths

• Spectral Types: O, B, A, F, G, K, M

• "Stellar Mass" #8 Video Lecture

• Binary Star Systems

• Mass Information from Doppler Shift of Spectra from a Binary Star System

• "Stellar Brightness and the H-R Diagram" #9 Video Lecture

• Absolute Brightness or Luminosity Versus Apparent Brightness

• Light From Stars Obeys an "Inverse Square Law"

• The Hertzsprung-Russell or H-R Diagram

• H-R Diagram with the Instability Strip

• "Spectroscopic Parallax" #10 Video Lecture

• Traditional H-R Diagram with the Absolute Magnitude Scale (on right-hand side)

• Our Sun as Red Giant

• The Red SuperGiant Betelgeuse (Hubble): Diameter is Larger than Jupiter's Orbit Around the Sun

• Comparing Sizes: SuperGiants to White Dwarfs

Week 3 (June 1 - June 5) Video Lectures and Images

• "Main-Sequence Birth" #11 Video Lecture

• An Interstellar Medium Containing Carbon Monoxide (Radio Frequencies)

• Cold, Molecular, Star-Forming Cloud (Infrared Frequencies)

• Interstellar Dust Grain: Easily Scatters Blue Light

• Pink Floyd DSOM: Scattering of Light: Violet and Blue Scatter More (Bending Angle Greater) Than Red and Orange

• Blue Sky and Red Dawn on Earth

• Atmospheric Scattering of Light: Blue Daytime Skies and Red Dawn

• Gravitational Forces Generate Lumpy Protostar

• Birth Process of Star

• Artistic Rendition of Star Birth

• Main-Sequence Lifetimes

• Red Dwarfs

• "Variable Stars" #12 Video Lecture

• On The Road to Giantdom

• Main-Sequence Versus Giant

• "Death of Low Mass Stars" #13 Video Lecture

• The Helium Flash Turning Point

• Hydrogen-Shell Burning Star

• The Double-Shell Red Giant

• Nova

• "Death of High Mass Stars" #14 Video Lecture

• The Multiple Layers of a High-Mass SuperGiant

• Death of a High-Mass Star: Supernova (Crab Nebula Produced in 1054 AD)

• Visible Remnants of Supernova: Nebula (Eskimo Nebula)

• Neutron Star

• Pulsar

Week 4 (June 8 - June 12) Video Lectures and Images

• "Black Holes" #15 Video Lecture

• The Geometry of a Black Hole

• Einstein: General Relativity

• Postulate of General Relativity: Equivalence Principle

• BTSOTC: Unruh Radiation and Violation of Equivalence Principle

• Matter Warps Space and Time

• Gravitational Redshift of Light Leaving Neutron Star

• Perihelion (and Aphelion) of Planet

• Shift of the Perihelion of Mercury

• Superstring Theory

• "Stephen Hawking" #16 Video Lecture

• Stephen Hawking: Primordial (Micro) Black Holes

• Schwarzschild: Discovered Event Horizon of Black Hole (Schwarzschild Radius)

• "No Hair" Theorem of a Black Hole

• Kerr Black Hole is a Spinning Black Hole

• Falling Into a Black Hole: OUCH

• Hawking Radiation: Black Holes Eventually Evaporate

• General Relativity Allows for Wormhole Solutions for Faster than Light Travel

• "Back To The Past": General Relativity Allows for Wormhole Solutions for Time Travel

• "Hydrogen Spin-Flip Radiation" #17 Video Lecture

• Edwin Hubble: Determined M31 Was a Galaxy 2 Million Light-Years Away

• Milky Way Galaxy (Edge View)

• "Supermassive Black Holes & Dark Matter" #18 Video Lecture

• Supermassive Black Hole

• Synchrotron Radiation

• Solid Body Rotation

• Keplerian Rotation

• Differential Rotation (Typical Galaxy)

• Dark Matter (Imagine that the green/yellow/orange strands are dark and you cannot see them.)

• "Types of Galaxies" #19 Video Lecture

• Grand Design Spiral Galaxy (M101)

• Flocculent Spiral Galaxy (NGC4414)

• Grand Design Spiral Galaxy (M81)

• Spiral Structure of Milky Way Galaxy -- possibly a "Barred-Spiral"

• Barred Spiral Galaxy (NGC1300)

• Elliptical Galaxy (M87)

• Lenticular Galaxy (NGC3115)

• Irregular Galaxy (NGC1068)

Optional Week 5 (June 15 - June 19) Video Lectures and Images

• "Clusters and Hubble's Law" #20 Video Lecture

• The Local Group, Big Players: Milky Way and Andromeda

• Galactic Rotation Curves of Nearby Galaxies

• Hubble's Plot: The Expansion of the Universe

• Hubble's Law

• A Globular Cluster in Milky Way: Omega Centauri (NGC5139), Visible by Unaided Eye

• LSS of Universe: Clusters & Superclusters that Neighbor the Milky Way (Near-Infrared Frequencies)

• "Quasars" #21 Video Lecture

• Multiplying by Light is Dividing by Light

• The Jets of Cygnus A (color enhanced, microwave frequencies)

• Looking for Quasars and Radio Galaxies: Australia's Telescope Compact Array (ATCA)

• Einstein During the Development of Special Relativity

• Supermassive Black Holes (SBHs) Power Quasars

• Blazars, Quasars, and Radio Galaxies

• "Gamma-Ray Bursters and Cosmological Constant" #22 Video Lecture

• Massive Star Collapses Forming Black Hole: Jets Along Rotation Axis Produce Gamma-Ray Long-Burst

• Gamma-Ray Short-Burst: Collision Involving Neutron Stars & Black Holes

• Einstein's Lambda: The Cosmological Constant

• Cosmological Constant Changes the Expansion of Universe

• Cosmological Redshift Due to Expansion of Space

• "Age of Universe and the CMBR" #23 Video Lecture

• Age Of Universe

• Big Bang Theory

• Stages of Expansion of Universe During Big Bang

• Evidence for the Big Bang Theory: Penzias and Wilson and their Microwave Antenna

• Spectrum of Microwave Radiation Closely Matches Big Bang Theory

• "High-Tech" Big Bang Detector in Your Home: Snowy Channel on an Antenna-Fed TV (1% is CMBR)

• Matter Types During the Expansion of Universe

• "Horizon Problem and Guth's Inflation" #24 Video Lecture

• The Horizon Problem

• The Effects of Inflation on the Cosmic Horizon

• Inflation Theory Solves Horizon Problem

Optional Week 6 (June 22 - June 26) Video Lectures and Images

• "Physics of the Very Small and 4 Forces" #25 Video Lecture

• The Four Forces (Again)

• Gravity: Binds Objects with Mass (Motorcycle's Front Wheel Overcomes Gravity)

• Electromagnetic: Binds Electrons to Protons to Form Atoms (Beryllium Atom)

• Strong: Binds Quarks to Form Protons, Neutrons, and Nuclei (Helium Nucleus)

• Weak: Quarks Change Into Other Quarks (Neutron Decay)

• "Feynman, Weinberg and Unification" #26 Video Lecture

• Weinberg: Co-Developed the Electroweak Theory

• Feynman: A Genius Among Physicists

• Feynman Diagrams

• Feynman's Feynman Diagrams on Feynman's Van

• Radiation-Dominated Then Matter-Dominated

• "Fate of Universe & Dark Energy" #27 Video Lecture

• Big Crunch

• Dark Energy

• The 3 Possible Global Geometries of the Universe

• "Vacuum Energy" #28 Video Lecture

• Vacuum Energy Due to Virtual Pairs

• Lawrence Krauss (with S. Hawking): Quintessence, The Variable Vacuum Energy

• Small Scale Structure of Our Universe

Important Dates

• Exam 1 (online): Monday, June 1 from 11:00 AM to Noon

• Exam 2 (online): Monday, June 15 from 11:00 AM to Noon

• Optional Exam 3 (online): Monday, June 29 from 11:00 AM to Noon

Exam Study Guides

• Exam 1 Study Guide

• Exam 2 Study Guide

• Exam 3 Study Guide

Exam Information

• Scores will be posted to Canvas.

• Students need not take last exam, if they are satisfied with their scores on the first two exams.

Weighting

• Exams: 100 % (we use only your two best exam scores)

Grades

• Standard grading percentages are employed.

• There is (unadvertised) curving on the C range and to a lesser degree, some curving on the B and A ranges.

Official Syllabus

• Syllabus (PDF).   Take with a grain of salt, mostly a formality.

Amazon.com Links for Previous Textbooks (old)

• The Cosmic Perspective: Stars and Galaxies (7th Edition)

• The Cosmic Perspective, Both Volumes (7th Edition)

• The Cosmic Perspective, Both Volumes (6th Edition)

• Amazon.com Textbook Rentals

Links to the Optional Textbook (Fall 2020 Only)

• Textbook purchase is totally optional.

• Universe: Stars and Galaxies, Sixth Ed, 2019, Freedman; Geller; Kaufmann (paperback and loose-leaf)

• Universe: Stars and Galaxies, Sixth Ed, 2019, Freedman; Geller; Kaufmann (eTEXT)

Imagining the Tenth Dimension

• Many thanks to Ryan Bertram (Astro A100 student), who introduced me to this neat YouTube video (courtesy of Rob Bryanton, Canadian author) that discusses the ten possible dimensions of our universe.

• Imagining the Tenth Dimension

Gravity Simulator

• PhET's page that demonstrates elements of gravity.

• PhET Gravity Simulations

Sizes (Orders of Magnitude)

• Many thanks to Elizabeth Potter (Astro A105 student), who showed me this neat webpage highlighting the relative sizes from the Local Group down to Quarks (and the corresponding orders of magnitude, or powers of ten)

• Secret Worlds: The Universe Within

Excellent Beginner's Telescope for General Astronomy

• Orion SpaceProbe 130ST Equatorial Reflector

• Other Telescopes Available in the Astro 100 Store

• Texts Also Available in the Astro 100/105 Store

FYI (and Just For Fun)

• Big Stig

• That's A Nice One, I Made That

• Top Gear

• Hans Stuck Around Nurburgring

• Is Newton's Second Law Correct at Small Accelerations?

• Top Gear's Review of GTI W12

• Rossi And a Yard of Bricks

• Mustangs and Corvettes Pray That They Do Not See This Dub At The Track (Warning: Contains Expletives)

• MESSENGER's Color-Enhanced Imagery of Mercury

• Our Solar System Might Be Rare

• Make Room For MakeMake

• String Theory: The Myth Of Time

• Video Images from 2008 Indy MotoGP

• The Official MotoGP.com

• Latest "Crash.net" News

• MotoGPod

• RideOnTwo.com

• Latest Yamaha Racing News

• MotoGP at Indy

• The Old, Old Server

• Thanks for the new Hummer! (I need to get in there and get those windows washed.)

• F1 and MotoGP Technology Available Today in the Showroom

• DeLorean (in street mode) Side Profile

• Mobile Proton Accelerator Pack

• Time-Elapsed Solar Prominence

• Plage Cloud

• Rhubarb Pie

• Mr. Weinberg (pic 1)

• Mr. Weinberg (pic 2)

• Mr. Weinberg (pic 3)

• Mr. Weinberg (pic 4)

• Mr. Weinberg (pic 5)

• Mr. Weinberg (pic 6)

• Prominences, Filaments, Plages

• Wave

• Electromagnetic (EM) Spectrum

• EM Spectrum and relative sizes

• EM Doppler Shift

• White Light is All the Colors

• Photon Absorption and Emission

• Hydrogen Spectra

• Blackbody Spectral Profiles

Physics At Noblesville High

• Physics Demo at Noblesville High School

Department of Physics, IU Indianapolis - Updated on June 1, 2025 at 2:30 PM EDT