Physics 1161: Lecture 29
De Broglie Waves, Uncertainty, and Atoms
sections 30.5 30.7
Compton Scattering
This experiment really shows photon momentum!
Pincoming photon + 0 = Poutgoing photon + Pelectron
Electron at rest
Outgoing photon has
momentum p and

Hermitian linear operator Real dynamical variable
represents observable quantity
Eigenvector
A state associated with an
observable
Eigenvalue
Value of observable associated
with a particular linear operator
and eigenvector
Copyright Michael D. Fayer, 200

Bohrs successes
and failures:
The wave nature
of the electron
Proceed with caution
The next three classes will be the most
difficult (conceptually) in the course. Do
not get discouraged. It all makes sense
once you get through it.
The Photon and Quantum
R

Derivation of Rutherfords scattering formula
1. Model assumptions
The interaction between alpha particles and atomic nuclei is formed only by Coulomb interaction; i.e. electrostatic forces between charged particles; all other
forces such as gravitational

Lecture 11
Dispersive waves.
Aims:
Dispersive waves.
Wave groups (wave packets)
Superposition of two, different
y
frequencies.
Group velocity.
Dispersive wave systems
Gravity waves in water.
Guided waves (on a membrane).
Dispersion relations
Phase and

Waves: Phase and group velocities of a wave packet
The velocity of a wave can be defined in many different ways,
partly because there are different kinds of waves, and partly
because we can focus on different aspects or components of any
given wave.
The w

DeBroglie Hypothesis
Problem with Bohr Theory: WHY L = n ?
have integers with standing waves: n(/2) = L
consider circular path for standing wave:
n = 2r
from Bohr theory: L = mvr = nh/2
Re-arrange to get 2r = nh/mv = n
Therefore, n = 2r = nh/mv, which

FSK 314 2014
Guidelines for Test 1
Discussion questions to prepare and topics of special importance:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Nature of an inertial reference frame and the postulates of special reltivity;
Time dilation (inlcuding derivation)

FSK 314 Guidelines 2013 Semester test 2
(To be written on 15 April)
The test covers the theory and of chapters 2 to 5 as well as these problems from these
chapters for which memos will be made available through email or on the Physics FTP
server.
The test

CHAPTER 5
Wave Properties of Matter and Quantum Mechanics I
5.1 X-Ray Scattering (review and some more material)
5.2 De Broglie Waves
5.3 Electron Scattering / Transmission electron microscopy
5.4 Wave Motion
5.5 Waves or Particles?
5.6 Uncertainty Princi

PHY 102: Quantum Physics
Topic 3
De Broglie Waves
Wave-particle duality
De Broglie Waves
Particles in boxes: Energy quantisation
Quantisation of orbital angular momentum in Bohr model
Einsteins postulate
A beam of light can be treated as a stream of parti