Friday, March 28, 2008
Announcements:
Assignments:
- Answer the recommended conceptual exercises and problems for
Chapter 13, and check your understanding by
looking at the answers in the back of the textbook.
- Continue working on your Web Project, and send me the URL for
your group's website once it is posted.
- For 2 days worth of class participation credit, you are
encouraged to create your own personal website in your UNC server space
(www.unc.edu/~onyen). This website does not have to be anything fancy,
just something other than the current default message that appears for
a blank webpage. Once you have completed this assignmment, send
me your URL.
Chapter 13 - Quantum Physics - "probably the most successful
theory ever invented" (Hobson, p.299)
This chapter synthesizes many concepts from previous chapters.
Quantization of energy
Examples of quantization
Digital versus analog: digital = discrete,
binary (1 or 0); analog = continuous
Application: quantum computing
Terminology: What is meant by a "quantum leap"?
Light is a wave in an EM field. What is "waving"? [the
field]
Planck's constant (h) and
quantization: En =
nhf, where h = 6.63 x 10-34 J*s
(note: this is a very small number!)
1 photon = 1 quantum of
energy: hf
photons are not really particles but "wave packets"
Can we see individual photons?
Photons and photoelectric effect
- energy, work function, cutoff
frequency, max K
KEmax = E - Wo
Einstein is most famous
for his theory of relativity and E = mc2, but he won the
Noble prize in physics (1921) for his discovery of the photoelectric
effect.
Double-slit experiment with
light and matter - similar results, therefore both behave like waves!
The wave nature of matter and matter fields
The de Broglie wavelength, wave-particle duality: lambda = h/mv
Wavelength and resolution
X-ray diffraction
electron microscope
Probability density distributions
Quantum uncertainty: Heisenberg uncertainty principle: x*mv
> h/2pi; E*t > h/2pi
Schroedinger's
equation
Critique of the movie trailer from Down
the Rabbit
Hole: The
Double Slit Experiment