Here is a summary of some of the points from Dr. Weaver’s lectures
Lecture Title: Energy Scales- From Megahertz to Terahertz and Back
Atoms moving at a speed of about 500m/s corresponding to the speed of about 300k, approximately 1/4eV. This corresponds to wavelength of infrared light
Getting towards visible light, the vibrational modes are excited.
Visible light energies-> 2-3 per photon/atom. Room temperature is about 40ev.
Chemistry forces: Electrostatics and quantum. At 13.5eV is the ionization constant of hydrogen, ˝ of an atomic unit of energy. E= 1/2mc2 (q/4.5K)2 *[other factors]
Kline’s Structure Constant
From 100MeV->1GeV: Neutron and Proton substructure
1GeV->10GeV: Quarks and Gluons
GeV-> TeV: Substructure of Matter
Cosmic rays visible up to 10-15 eV
Cosmic microwave rays at a temperature of 3K-> then we are back at MeV
Lecture Title: Waves and Lasers
From Maxwell’s Equations: Electric charge produces current
Electric current produces a magnetic field
Changing magnetic field produces a current, Faraday’s law
Dispersion of light
The real part and the imaginary part
Quantum state of electromagnetic field -> no photon present.
For stimulated emission/coherent phase
The coherent phase is a laser. Quantum phase is a superposition of quantum states.
Two things about lasers: a) Excited medium b) Resonator (Optical cavity)
The Transition coefficient and the incident coefficient.
Condition or threshold for the operation of the laser -> Imaginary part of refractive index -> absorption & loss.
Gain -> excited population – ground state population
Lecture Title: Atoms and Molecules
From Classical to quantum Mechanics
Classical angular momentum-> ˝ Iω2 = L2/2I
Quantum Mechanics = L (Ћ) π/2MI
Energy Operator – Hamiltonian + Wave Function
Hψ = Eψ + ίЋω
Hψ = ίЋ δQ/δt
Probability Density dependence on time?
Lecture Title: How Molecules Work
Lecture Title: Superposition in Quantum Mechanics
Schrodinger Equation-> ψ = Hφ
Quantum Beat Spectroscopy
Ψ (φ) = c1 φ1 + c2 φ2
Fluorescence amplitude = Integral φ (over the decay operator)
Rabi Oscillations: 2 states, electric field applied to coupled field
Lecture Title: Are atoms Real
Yield of scattered particles = Number of particles * (σtIAί/A).
Yield per particle = Flux * cross sectional area
Detected Yield = Efficiency * Flux*Cross sectional area
Δ Yield per target = Flux * (δI/δΩ)
No lecture, tornado hits campus.
Lecture Title: Energy Levels of the Hydrogen Atom
We learned about the quantum theory of angular momentum as well as
The Schrodinger Equation
Dirac Theory with Correction
The Fine Structure
The Hyperfine Structure
Lecture Title: Symmetry and Neutrino Physics
Linear, Elliptical Circular Polarization field
Right hand circularly polarized -> E0Cos (ωt-nz)
The relative phase is physically relevant
Real part -> E0(x+y) eίωt
Lecture interrupted abruptly because we had to evacuate the building.
No lecture, Cardwell Hall is closed and inaccessible
Lecture Title: Relative Phases and Neutrino Mixing
Intensity of light, e.e=E12Cos2ωt
Time Average Value = ˝(E12 +E22) = 1/2E02
From above relation we see that E1=E0*Cosθ, E2 = E0*Sinθ
E(t) =E0*Cosωt (xCosθ + ŷSinθ)-> written as linearly polarized time dependence of intensity
E(t)=RexE0eiωt + E0yeiωt
Photon has spin and Г =1
In classical physics, Average Value of Cosθ = Sinθ = 0, and average Value of Cos2θ= Sin2θ= 1/2
Now to quantum mechanics
Let φ be some general quantum mechanical state.
Key question - Given that a photon is in some quantum mechanical state, what is the probability that it’s in state φ?
Answer = (|ψ, φ|)2
Before observation quantum mechanical state was a single vector, (φx + φy)/
After observation, quantum state is either φx or φy
Lecture Title: Forces between Molecules
We discussed the Central Field theorem
Lowest Energy Configuration
Chemical bond requires shared pair of electrons-> From Coulomb’s law and quantum mechanics.
Quantum Mechanics explains why atoms weakly attract at long distances, strongly repelling at small distances.
Lecture: Graduate School.
The lecture was dedicated to everything we needed to know about graduate school. Some of the points Dr. Weaver touched on include
Your choice of grad school: Consider the programs that these schools offer, the location, the level of funding the university receives for the research program you are interested in, the perceived attitude of the professors towards the graduate students, the financial aspect as well (fellowships, teaching assistantship, etc).
Applying to Grad School: Have a sufficient list of schools you can realistically get into to and include a few wild cards.
The Physics GRE: Prepare adequately, and take several practice exams under timed conditions, work and discuss with friends. It is important for your admission into graduate school.
Paying for Graduate Studies: Through fellowships and teaching aids.
Be realistic about the level of work you should expect a graduate school, because grad school is hard.
Lecture: Holography and Holograms
Coherence length- pretty short
Grating Spacing -> Δ/Sinθ,
if Δx Cosθ/λ ==Integer, we get a dark spot
Lecture: General Relativity
Tour of the K-state Nuclear Reactor