Schedule for Physics 704 - Spring 2015

PHYS 704 Home Page

All problem numbers refer to the third edition of Jackson and / or the third edition of Griffiths!

Day, Date, Year Lecture Content and Homework Assignment
Mon. Jan. 12, 2015 Lecture: Introduction to frequency dependence of the refractive index via the spring model of an atom.
Homework (HW #1): Consider a hydrogen atom in its ground state.
(a) Using the ground-state wavefunction, show that the restoring force for displacements small compared to the Bohr radius obeys Hooke's Law. Find the spring constant and the natural frequency.
(b) For such an atom in the atmosphere, bathed in sunlight, would the displacement actually be small compared to the Bohr radius? [For the electric field amplitude you may use, for instance, the answer to last semester's homework of Dec. 1.]
Wed. Jan. 14, 2015 Lecture: Refractive index as a function of frequency for non-permeable media.
Homework (HW #1): [Due to difficulty of obtaining data, this problem has been suspended. If a useful data table is found, it may be reinstated later.] Pick a multi-electron gas (He and beyond) at STP and apply Jackson's eq. (7.51) as best as you can, by finding values of the various constants therein, and see how well it predicts the actual dielectric constant. Good luck on your choice of gas! Don't pick the same gas as anyone else you know!
Fri. Jan. 16, 2015 (WK1) Lecture: Low and high frequency limits of the dielectric constant expression. Conductivity and refractive index of metals and plasmas.
Homework (HW #1): Jackson 7.4.
Tue. Jan. 20, 2015 Lecture: A lightning review of Special Relativity.
Homework (HW #2): No Homework.
Wed. Jan. 21, 2015 Lecture: The various effects and their characteristic times that determine time-varying fields in conductors: charge clearing, collisions, plasma oscillations, Ohm's Law, diffusion of fields, energy loss due to electrical resistance and radiation, electric circuit effects.
Homework (HW #2): No Homework.
Fri. Jan. 23, 2015 (WK2) Lecture: Propagation of waves in a waveguide: sinusoidal longitudinal and time dependence. Splitting of the Maxwell equations into longitudinal and transverse components.
Homework (HW #2): No Homework.
Mon. Jan. 26, 2015 Lecture: Waveguide equations continued: the transverse fields in terms of the longitudinal fields. TE, TM, and TEM waves.
Homework (HW #3): No homework.
Wed. Jan. 28, 2015 Lecture: Solving waveguide problems: boundary conditions, geometry. Non-existence of TEM waves in waveguides.
Homework (HW #3): Jackson 8.4 (a).
Fri. Jan. 30, 2015 (WK3) Lecture: Waveguides concluded: a summary of how to solve for the modes in a waveguide, which ones propagate, cylindrical waveguides, cavities. The different approaches of Jackson and Griffiths to radiation from sources. Approximations (with reasons) involving d, λ, and r.
Homework (HW #3): Jackson 8.6 (a).
Mon. Feb. 2, 2015 Lecture: The vector potential and the magnetic field due to a small volume of oscillating charges / currents in the E1 approximation.
Homework (HW #4): Jackson 9.5, with the following simplifications:
Part (a): Work out only the scalar potential; the vector potential was done in class.
Note: As discussed in Jackson at the end of section 9.1, the monopole term in the 1/distance expansion does not yield radiation. Instead, we must replace the exponential with -ik · x'(1 - 1/ikr), which results from using the expansion (9.12).
Part (b): Work out only the electric field; the magnetic field was done in class.
Wed. Feb. 4, 2015 Lecture: Radiation fields for E1 radiation. The Poynting vector and radiated power. Dependence of power on distance, direction, frequency; polarization of the radiation.
Homework (HW #4): No homework.
Fri. Feb. 6, 2015 (WK4) Lecture: Summary of E1, M1, E2 radiation: fields, differential power (angular distribution) and total power. The Larmor formula for dipole radiation. Examples of oscillating electric dipoles (two charges, two-wire dipole antenna) and magnetic dipoles (loops, pulsars). The radiation resistance of antennas.
Homework (HW #4): Jackson 9.3.
Mon. Feb. 9, 2015 Lecture: E1 and M1 scattering of electromagnetic radiation by small scatterers (size << wavelength).
Homework (HW #5): Jackson 10.1 (a).
Wed. Feb. 11, 2015 Lecture: Rayleigh scattering, the blue sky, and polarization asymmetry. Polarization of light scattered from the sky.
Homework (HW #5): Jackson 10.1 parts (b) and (c).
Fri. Feb. 13, 2015 (WK5) Lecture: No Rayleigh scattering in the Martian sky, Reflection of rain by radar, Huygens principle and single-slit diffraction.
Homework (HW #5): No homework.
Mon. Feb. 16, 2015 Lecture: Relativity Quiz and discussion of the quiz. Dipole radiation pattern and N-slit diffraction pattern.
Homework (HW #6): No homework.
Wed. Feb. 18, 2015 Lecture: Derivation of the Huygens-Fresnel principle [Jackson's equation 10.86] in the scalar approximation.
Homework (HW #6): Consider a plane wave (wavenumber k) incident along the z direction and perpendicular to a large conducting screen with a small rectangular aperture whose (x, y) dimensions are (2a, 2b). Thus, we could say that x lies in the range [-a, a] and y in the range [-b, b]. A screen is placed a distance L downstream, and is also perpendicular to the z direction. Find an expression for the diffraction pattern (intensity distribution) on this screen assuming that the screen is far away (tens of cm or farther) and the aperture widths are at most a few wavelengths.
Fri. Feb. 20, 2015 (WK6) Lecture: Poisson's (or Arago's) Spot: derivation of the scalar wave on axis.
Homework (HW #6): Jackson 10.11 (a) and (b).
Mon. Feb. 23, 2015 Test #1: Everything covered up to Fri., Feb. 13: essentially all the material we covered in Chapters 7, 8, 9, 10.
Homework (HW #7): No homework.
Wed. Feb. 25, 2015 Lecture: A brief history of units in electromagnetic theory. Introduction to Special Relativity: the Galilean transformation and its impact on the electromagnetic wave equation.
Homework (HW #7): No homework.
Fri. Feb. 27, 2015 (WK7) Lecture: The principle of relativity as stated by Galileo. The Voigt and Lorentz transformations. Invariance of the wave equation under Lorentz transformations and constancy of the speed of light.
Homework (HW #7): Jackson 11.1.
Mon. Mar. 2, 2015 Lecture: Review of Test 1.
Homework (HW #8): No homework.
Wed. Mar. 4, 2015 Lecture: Test 1, take 2.
Homework (HW #8): No homework.
Fri. Mar. 6, 2015 (WK8) Lecture: The coordinate 4-vector. Greek and Roman indices and their meanings. Contra- and co-variant coordinate 4-vectors. Inner products of 4-vectors. The Lorentz transformation matrix and its inverse. Arbitrary 4-vectors. A simple problem involving length contraction and simultaneity.
Homework (HW #8): Problems 3, 4 in the distributed "Relativity Problems".
Mon. Mar. 16, 2015 Lecture: The inverse and reverse Lorentz transformations, and how they are the same thing. Lorentz invariance of inner product of two 4-vectors. Contra- and co-variant 4-vectors defined, and their Lorentz transformations. Minkowski spacetime of special relativity and the length of 4-vectors defined using the Minkowski metric. Transformation of the gradient 4-vector.
Homework (HW #9): No homework.
Wed. Mar. 18, 2015 Lecture: Invariance of the differential length squared leads to the Minkowski metric being the same in all inertial frames. The rest frame, instantaneous rest frame, and / or co-moving rest frame of a particle. Proper time and time dilation. Spacetime diagrams. Worldlines of particles. The light cone. Timelike and spacelike intervals.
Homework (HW #9): Jackson 11.3.
Fri. Mar. 20, 2015 (WK9) Lecture: Spacetime diagrams for the motion of four observers in two different frames of reference: how the relative position of events on the diagrams changes in a counter-intuitive way. Lengths of vectors on spacetime diagrams and how the triangle inequality is not satisfied in Minkowski geometry. Plots of hyperbolic functions. Rapidity.
Homework (HW #9): Jackson 11.6.
Mon. Mar. 23, 2015 Lecture: Spacelike, lightlike, and timelike intervals. Four-velocity. Four-momentum. Use of Lorentz invariants to solve kinematic problems. First problem solved this way: the velocity addition formula.
Homework (HW #10): No homework.
Wed. Mar. 25, 2015 Lecture: More 4-vector dot product applications: The Doppler Effect Formula. The Compton Effect Formula.
Homework (HW #10): Jackson 11.19.
Fri. Mar. 27, 2015 (WK10) Lecture: 4-vector dot product applications continued:
  1. Two-body decays: momentum of final state particles.
  2. Minimum energy required to produce a mass M in (a) e+e- collisions, and (b) cosmic ray - CMB photon collosions.
Homework (HW #10): Jackson 11.23.
Mon. Mar. 30, 2015 Lecture: The 4-current and the 4-potential. Casting the continuity equation, the wave equation for the 4-potential, and the Lorenz condition as relativistically covariant equations. The quotient theorem. A relativistically fast run through a relativistically fast falling rain. The attractive Lorentz force on a charge moving parallel to and with speed identical to that of a linear current. A paradox: the same charge appears to see no force in its rest frame and is not attracted to the wire.
Homework (HW #11): No homework.
Wed. Apr. 1, 2015 Lecture: Resolution of the paradox: transformation of the magnetic field to an electric field. Definition of the electromagnetic field tensor.
Homework (HW #11): Jackson 11.27.
Fri. Apr. 3, 2015 (WK11) Lecture: More on the electromagnetic field tensor. Transformation of Electromagnetic Fields.
Homework (HW #11): (a) Obtain the transformation in the form of Jackson's equation (11.149).
(b) Read the rest of section 11.10 and obtain the remaining important equations for the fields of a moving charge on pages 559 and 560 [equations 11.151, 11.152, 11.153, 11.154, and the unnumbered equation between 11.152 and 11.153].
Mon. Apr. 6, 2015 Report by Suraj Poudel: Polarization by Double Refraction.
Lecture: Gauge invariance and invariance of the antisymmetric electromagnetic field tensor in the Lorenz gauge. The inhomogeneous and homogeneous Maxwell equations. Lorentz transformations viewed as elements of a Lie group that can be generated by a continuous transformation. The infinitesimal generators must form an antisymmetric tensor.
Homework (HW #12, due Apr. 17): Show that the Jacobi identity satisfied by the antisymmetric electromagnetic field tensor leads to the homogeneous Maxwell equations.
Wed. Apr. 8, 2015 Lecture: Proper and improper Lorentz transformations. Generators of rotations and boosts.
Homework (HW #12, due Apr. 17): Any one of Jackson 11.10 or 11.11.
Fri. Apr. 10, 2015 (WK12) Report by Francie Cashman: Frequency Dispersion of Dielectric Gases.
Report by Saba Arash: Center-Fed Antenna.
Report by Alyssa Loos: Energy Gains and Losses in a RF Cavity.
Lecture: Lorentz invariants formed from the field tensor. Rate of change of 4-momentum. The spin and momentum 4-vectors and how they behave differently under boosts.
Homework (HW #12, due Apr. 17): Jackson 11.14.
Mon. Apr. 13, 2015 Report by Dheyaa Alameri: Radiation Fields of a Linear Wire Antenna.
Lecture: Thomas Precession.
Homework (HW #13, due Apr. 22): Jackson 11.12.
Wed. Apr. 15, 2015 Test #2: Everything in the Special Relativity Chapter up until the first half of the lecture on Monday, April 6. In other words, essentially all of Jackson sections 1, 2, 3, 4, 5, 6, 9, 10 in Chapter 11.
Homework (HW #13): No homework.
Fri. Apr. 17, 2015 (WK13) Report by Cory Dolbashian: The Meissner Effect and the London Penetration Depth.
Report by Sara Fitzgerald: Schumann Resonance.
Lecture: Derivation of the BMT Equation and applications to special cases.
Homework (HW #13, due Apr. 22): Thomas precession revisited: Starting from the BMT equation (11.164), derive equation (11.170). Unlike Jackson, you should not skip any steps (show all your work, with every step in detail).
Mon. Apr. 20, 2015 Lecture: Comparison of electron (or muon) momentum precession with spin precession. The extra rate at which the spin precesses is shown to be aγωc. The gyromagnetic anomaly as the high-point of precision electrodynamics; muon (g-2) experiments. Energy loss of charged particles in matter: the basic idea.
Homework (HW #14, due Apr. 27): Jackson 12.12 (Jackson has some Chapter 11 problems at the end of Chapter 12 - possibly by mistake or because relativity got split into two chapters from a single chapter in some previous version of the text).
Wed. Apr. 22, 2015 Lecture: Energy loss of a charged particle per unit distance. Maximum and minimum energy lost to a single electron.
Homework (HW #14, due Apr. 27): Jackson 13.1.
Fri. Apr. 24, 2015 (WK14) Lecture: Course review for final exam.
Homework (HW #14, due Apr. 27): No homework.
Mon. Apr. 27, 2015 Lecture: Preponed to Jan. 20, 2015.
But HW #14 is still due today!
Homework: No homework.
Wed. Apr 29, 2015
9:00 AM - 11:30 AM
FINAL EXAM: Covers ALL material!

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