The Physics of Crystal Growth and Pattern Formation in Ice. This
project is essentially a case study of the growth of ice crystals from
the vapor phase, the purpose of which is to better understanding
molecular attachment physics and pattern formation in nonlinear nonequilibrim systems. The diverse
morphologies seen in snow crystals are largely due to the bizarre
temperature dependence of ice crystal growth rates, a phenomenon that
was discovered 75 years ago and remains unexplained to this day.
We have been making precise measurements of the growth rates of the
different facets of ice crystals under controlled conditions to gain
insights into the temperature dependent molecular structure of the ice
surface and how it affects crystal growth.
Review Paper: Physical Dynamics of Ice
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|Some Past Research|
Laboratory Instrumentation for Physics Education. We
developed numerous instruments that are being used in physics teaching
labs at Caltech and at universities around the world, including an
ion trapping apparatus, a picometer-resolution laser interferometer, a
magneto-mechanical harmonic oscillator, and atunable diode-laser apparatus. I started Newtonian Labs to sell these teaching tools.
Advanced detector development for the Laser Interferometer Gravitational-wave Observatory (LIGO).
The LIGO project studies gravitational-wave signals from violent
astrophysical events, such as supernovae or coalescing neutron stars
and black holes. For more information on all aspects of the LIGO
project, see the LIGO web site. My work in LIGO focused on: 1) an instrument called the Thermal Noise Interferometer (TNI),
which was a test-bed suspended interferometer at Caltech, and 2) a
photothermal interferometer for measuring the properties of optical
coatings used in the LIGO detectors.
Laser Cooling and Trapping of Neutral Atoms. We
built laser-cooled magneto-optical atom traps in the early 1990s that
could capture and observe individual cesium atoms. This
technology was used to investigate the dynamics of atom trapping in the
low-atom-number limit. We also investigated the use of
microfabricated planar current structures for making microscopic
magnetic atom traps.
Helieseismology and the Large-Scale Structure of the Sun. Convective
motions near the solar surface generate acoustic waves that resonate
inside the Sun, resulting in global oscillation modes with periods
around five minutes. We made extensive measurements of these
global modes in the late 1980s at Big Bear Solar Observatory, recording
Doppler images of the entire solar disk each minute for many months on
end. Analysis of these tens of thousands of images allowed us to
measure the solar mode frequencies to unprecedented accuracy. By
examining the mode frequencies and amplitudes, as well as the frequency
splittings of mode multiplets, information about the interior structure
and dynamics of the Sun could be extracted, including a measure of the
interior rotation rate of the Sun.
List of Publications
- E-mail: email@example.com
- Phone: 626-395-3722
- Address: Physics Department, Caltech 264-33, Pasadena, CA 91125