### AST 462: Physics of Astrophysics II (Spring 2022):

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**Lecture Notes:
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Lecture 1 Basic relation between fluids and plasmas, derivation of collisionless Boltzmann equation

Lecture 2 Invariants, Derivation of Collisonal Boltzmann Equation, Maxwellian distribution as steady state, moment equations

Lecture 3 Moment equations, derivation of fluid equations for viscous flow
with thermal conductivity, derivation of transport coefficients.

Lecture 4:
Vorticity, Incompressible flow, Hydrostatic equilibrium
Solar Corona, Bernoullis principle

Lecture 5:
Robust proof of Kelvin Circulation Theorem/Magnetic Flux Freezing, Relation between MHD and Fluids, Viscous Flow

Lecture 5a:
Discussion of physical difference between viscosity and magnetic diffusivity

Curveball in Rarefied Atmosphere (technical paper)

Discussion of Curves (= "Swings") in Cricket also from NASA

Lecture 6:
Importance of Reynolds Number, Onset of Turbulence, and Drag Forces

Lecture 7:
Compressibility, Sound Waves, Shocks

Lecture 8:
More on Shocks, Supernovae as an example, Justifying the Shock
Thickness, Regimes of Blast Wave Evolution

Lecture 9:
Instabilities: Convection and Buoyancy, Schwarzchild Criterion, Brunt-Vaisala Frequency

Lecture 10:
Turbulence: basic concepts, energy spectrum Kolmogorov theory, Turbulent diffusion

Lecture 11:
Turbulent diffusion continued

Lecture 12:
Introduction to Accretion: Accretion in a binary system, circularization radius, need for mechanism of angular momemtum transport

Lecture 13:
Derivation of Viscous Torque in Accretion Disks; parameterizing the viscosity

Lecture 14:
More on accretion: Accretion speed as diffusion, hydrostatic equilibrium

Lecture 15:
Still more accretion: Steady Accretion Disks, Luminosity and Spectrum

Lecture 16:
Hydrodynamics and Rotating Flows: Geostrophic flows, Rossby Number
Still more accretion: Steady Accretion Disks, Luminosity and Spectrum

Lecture 17:
MHD I: Derivation of Ohm's Law from Two-fluid Equations; Derivation of the Jx B force in the Momentum equation for MHD; Derivation of the Magnetic Induction Equation

Lecture 18:
MHD II: Physical interptatoin of J x B force:
pressure vs. tension; Flux freezing; Magnetostatics and confinement of
"jet" by magnetic forces

Lecture 19:
MHD III:
Physical description of stability of magnetic structures;
magnetic buoyancy; Graphical description of solar cycle dynamo;
Ferarros law of isoration and role of fields in angular momentum
transport