------------------------------------------------------------------------------- KEY TOPICS - Astronomy 130: Black Holes in the Universe - Gravity's Fatal Attraction ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- Week 01 - Introduction, Newtonian Gravity ------------------------------------------------------------------------------- * Main discoveries of Copernicus, Kepler, Galileo relevant to the Solar System * Newton's laws of motion and gravity * Escape velocity * Finite speed of light * Newtonian "black holes" * Absolute space and absolute time * Perihelion shift of Mercury * Michelson-Morley experiment and its implications * Fitzgerald contraction * Problem of "open field lines" in electromagnetism ------------------------------------------------------------------------------- Week 02 - Special Relativity, General Relativity ------------------------------------------------------------------------------- * Special theory of relativity * Length contraction and time contraction * Basic tests of special relativity - atomic clock tests, Global Positioning System, atmospheric muons * Principle of relativity * Absoluteness of speed of light * Aberration of light * Relativistic effects upon inertia * Relation of mass and energy * Principle of equivalence * Gravitational deflection of light * Eddington's 1919 expedition * Gravitational lensing by galaxies ------------------------------------------------------------------------------- Week 03 - General Relativity, Curvature ------------------------------------------------------------------------------- * Gravitational time dilation * Einstein's "philosophical" problems with Newton's law of gravity * Tidal gravity * Gravity as the curvature of spacetime * Geodesics * Einstein's law of curvature * "Rubber sheet" analogy * Schwarzschild spacetime geometry * Gravitational redshift * The Schwarzschild radius * Newtonian "black holes" versus General Relativistic black holes ------------------------------------------------------------------------------- Week 04 - Stars and Their Fates ------------------------------------------------------------------------------- * Normal stars as gravitationally bound fusion reactors * Possible fates for stars - white dwarfs, neutron stars, black holes * Eta Carinae as an example of a star that will likely make a black hole * Bosons and fermions * Pauli exclusion principle * Quantum-mechanical degeneracy pressure * Support of white dwarfs by electron degeneracy pressure * Basic properties of white dwarfs * Sirius B * Chandrasekhar limit * Eddington vs. Chandrasekhar controversy * Support of neutron stars by neutron degeneracy pressure * Basic properties of neutron stars * Maximum mass for a neutron star * Apparent inevitability of black-hole formation in the Universe * Oppenheimer & Snyder calculation of black-hole formation * Wheeler's naming of "black holes" ------------------------------------------------------------------------------- Week 05 - Black Holes in Binaries and Accretion Disks ------------------------------------------------------------------------------- * Plausible distances for astronomically expected black holes * Methods to find black holes - gravitational lensing, black holes accreting from interstellar gas clouds, black holes in binary systems * Measuring black-hole masses in binary systems * Accretion basics in binary systems - wind accretion, stream accretion * Basic physical principles of accretion disks * Accretion as an efficient source of power * Current observational status of black holes in binary systems ------------------------------------------------------------------------------- Week 06 - Gamma-Ray Bursts ------------------------------------------------------------------------------- * History of the discovery of gamma-ray bursts * Basic observed properties of gamma-ray bursts * Challenges in determining the nature of gamma-ray bursts * Compton Gamma-Ray Observatory findings on gamma-ray bursts * BeppoSAX and the discovery of gamma-ray burst afterglows * Relativistic blast waves in gamma-ray bursts * Anisotropy of gamma-ray bursts * Hypernovae * Mergers of two neutron stars in a binary system * Swift Gamma-ray Burst Explorer * Main Swift discoveries on gamma-ray bursts ------------------------------------------------------------------------------- Week 07 - Galaxies and Supermassive Black Holes ------------------------------------------------------------------------------- * Number of galaxies in the Universe * Bulge components of galaxies * Fractional black-hole mass contribution to a typical galaxy * Basic properties of galactic nuclei * Physical processes in galactic nuclei relevant to black-hole formation * Sgr A* and its basic properties * Stellar orbits around the Galactic supermassive black hole ------------------------------------------------------------------------------- Week 08 - Active Galactic Nuclei ------------------------------------------------------------------------------- * History of the discovery of active galaxies * Luminous non-stellar emission sources at galaxy centers * Emission-line spectra of active galactic nuclei and their implications * Multiwavelength emission of active galactic nuclei * Rapid and large-amplitude variability of active galactic nuclei * Characteristic sizes of active galactic nuclei * Particle jets * The basics of the supermassive black hole + accretion disk model * Efficiency of black-hole accretion as relevant to powering active galaxies ------------------------------------------------------------------------------- Week 09 - Active Galactic Nuclei, Jets ------------------------------------------------------------------------------- * Black-hole spin * Kerr solution for black holes * Synchrotron radiation and the emission from radio jets and radio lobes * Energy content of radio lobes * Powering of radio lobes with particle beams * Jets from Galactic microquasars * M87 as a laboratory for studying jets from active galaxies * Observations of jet formation on small scales * Likely connections between jet formation and spinning black holes * Remaining mysteries about jet formation ------------------------------------------------------------------------------- Week 10 - Quiet Black Holes in Galactic Nuclei ------------------------------------------------------------------------------- * Fraction of local galaxies that harbor active nuclei * The rise and fall of the quasars - remnant supermassive black holes * Searches for quiet supermassive black holes in normal galaxies * Quiet black holes found via the random motions of stars * Quiet black holes found via organized stellar motions * Quiet black holes found via the rotation of gas clouds * Quiet black holes found via maser disks - the case of NGC 4258 * Relations between black hole masses and the bulges of their host galaxies * Co-evolution of black holes and galaxies * Stellar tidal disruptions by supermassive black holes ------------------------------------------------------------------------------- Week 11 - Gravitational Waves ------------------------------------------------------------------------------- * Gravitational waves and the propagation of gravitational effects * Analogies between gravitational-wave radiation and electromagnetic radiation * Basic mechanism for the creation of gravitational waves - accelerate a massive object * Alternating "stretches + squeezes" from gravitational waves * Astronomically expected sources of gravitational waves * Expected sizes of effects from astronomically expected sources of gravitational waves * Binary system with two black holes as a fiducial gravitational wave source. Evolution of such a binary system from its formation through the merger of the two black holes. * What we can learn by detecting the gravitational waves from the merger of two black holes. * Binary pulsars and indirect evidence for gravitational waves * Earth-bound attempts to detect gravitational waves - LIGO * Space-based plans to detect gravitational waves - LISA ------------------------------------------------------------------------------- Week 12 - Kerr Black Holes and the No-Hair Theorem ------------------------------------------------------------------------------- * Most real black holes are probably spinning * Paths of particles dropped or thrown into spinning black holes * Shape of a spinning black hole * Accretion efficiency for spinning vs. non-spinning black holes * Energy content of the "swirl" of space around a spinning black hole * Charged black holes and why they probably don't exist in nature * Mass, spin, and charge completely describe a black hole - black holes have no "hair" * Price's theorem * Loss of black-hole magnetic fields via electromagnetic radiation * Loss of black-hole "mountain" via gravitational-wave radiation * The ultimate validation of the Oppenheimer & Snyder calculation ------------------------------------------------------------------------------- Week 13 - Black Hole Evaporation ------------------------------------------------------------------------------- * Problems mixing relativity and quantum mechanics * Primordial black holes - properties and possible formation method * Laws of thermodynamics - especially the second law of thermodynamics * Quantum mechanical uncertainty and vacuum fluctuations * Hawking's area-increase law * Connections between the second law of thermodynamics and Hawking's area-increase law * Black-hole radiation and evaporation * Characteristic timescales for black-hole evaporation * Searches for evaporating black holes ------------------------------------------------------------------------------- Week 14 - Singularities ------------------------------------------------------------------------------- * Uncertainties due to problems mixing relativity and quantum mechanics * Oppenheimer & Snyder's "crunch" of a star - concept of a singularity * Falling into a supermassive black hole - observed and felt effects * BKL singularity * Effects as one approaches a BKL singularity * Horizon implies singularity * Does singularity imply horizon? Cosmic censorship hypothesis. ------------------------------------------------------------------------------- Week 15 - Black Holes and Child Universes ------------------------------------------------------------------------------- * Possible connections between Big Bang event and singularity formation * Cosmological natural-selection hypothesis * Anthropic coincidences? Apparent "fine tuning" of our Universe.