Junior and senior physics majors attend our biweekly colloquium series, held on Tuesday afternoons at 4:30 pm in Shanahan B460. The talks are open to all students and to the public, and are frequently attended by scientists from the other Claremont Colleges, Cal Poly Pomona, and others. The series features speakers from a broad range of institutions and fields of physics.
HMC Physics Colloquium shot
Oct. 24, 2006 Karen Shell, Oregon State University
Diagnosing Climate Feedbacks in Atmospheric General Circulation Models
Many different feedbacks influence how the earth’s temperature, precipitation, and winds respond to changes in the energy budget of the planet (caused, for example, by increases in carbon dioxide or other greenhouse gases). Because there is only one realization of the actual climate, computational climate models are useful tools for studying different scenarios and climate configurations in a very controlled ...
Oct. 3, 2006 Adam Bernstein, Lawrence Livermore National Laboratory
Applied Antineutrino Physics: Reactor Monitoring with Cubic Meter Scale Antineutrino Detectors
Reactor antineutrino detection has matured to the point where it is feasible to stably monitor plutonium content and reactor power using a high statistics (hundreds or thousands of counts per day) antineutrino detector at a standoff of a few tens of meters. Our Lawrence Livermore National Laboratory/Sandia National Laboratories collaboration has deployed a detector to demonstrate this capability at a ...
Sept. 19, 2006 Bill Jones, Caltech
Imaging the Primordial Plasma: Recent Observations of the Temperature and Polarization Anisotropies of the Cosmic Microwave Background (CMB)
We discuss recent observations of the temperature and polarization anisotropies of the CMB, and the implications for our understanding of the cosmology, which (it appears), describes our Universe. We discuss in detail the results from the recent flight of Boomerang, and outline what we expect to learn from observations in the near future.
Sept. 12, 2006 Various students, Harvey Mudd College
Student Presentations of Off-Campus Research during the Summer of 2006
Greg Sandstrom and Steve Von der Porten,
Umachines - Pasadena, CA
Dr. Tom Tsao
Constructing a phase-shift interferometer to test MEMS deformable mirrors

Sam Skillman
Los Alamos National Laboratory
Brian O’Shea, T-06 Group, Theoretical Astrophysics
Computer simulations of star/galaxy formation

David Coats
U. of Minnesota REU Program
Dr. Jian Ping Wang
MEMS array of ferromagnetic islands for magnetic ...
Sept. 5, 2006 Chandrashekhar Joshi, University of California at Los Angeles
Laser- and Beam-Driven Plasma Accelerators
Scientists have been trying to use the tremendous electric fields in relativistic plasma waves to accelerate charged particles, and are now making substantial progress. If they succeed, future high energy accelerators will use plasma waves rather than microwave cavities as accelerating structures. Some accelerators, such as those used for radiation therapy will fit on a tabletop.

Research on using plasma ...

April 18, 2006 Arvind Rajaraman, University of California at Irvine
Dark Matter
I will review the evidence that most of the matter in the universe is dark; i.e. it does not absorb or radiate light. I will argue that dark matter is a new type of matter, qualitatively different from normal matter. In a few years, we will be able to identify the properties of this hitherto mysterious substance.
April 4, 2006 Physics Faculty, Harvey Mudd College
Recent Physics News, as Reported by Faculty Members of the Department of Physics
  • "The Arrival of the Cassini Spacecraft at Saturn and the Successful Landing of the Huygens Probe on the Moon Titan" -- Greg Lyzenga
  • "The Demonstration of Pyrofusion" -- Tom Donnelly
  • "Superfluidity in an Ultracold Gas of Fermions" --Vatche Sahakian
  • "The Brightest Burst of Light Ever Recorded From Outside the Solar System" -- Ann Esin
March 21, 2006 Re’em Sari, Caltech
The Formation of the Solar System
How do planets form and how long does it take? Why are their orbits circular and coplanar? What set the number of planets in our solar system? We address these fundamental questions providing a coherent story on the formation of our solar system.
March 7, 2006 John Clarke, University of California at Berkeley
The Ubiquitous SQUID: From Cosmology to Medicine
Many materials become superconducting at sufficiently low temperatures. In the superconducting state, electrons of opposite momentum and spin form Cooper pairs. These pairs constitute a single, macroscopic quantum state that is described by a quantum mechanical wave function with well defined amplitude and phase. This quantum state is responsible for the zero-electrical resistance of superconductors and for such properties as ...
Feb. 21, 2006 Michael Wood-Vasey (’98), Harvard University
The Accelerating Universe and You: The Past, Present, and Future of Exploring the Universe With Supernovae
The field of cosmology has been revolutionized in the last decade by the discovery that the expansion of the Universe is accelerating. This remarkable conclusion was first derived by using Type Ia supernovae as standardizable cosmological candles. Since this initial work, a number of complementary cosmological measurements have led to our current "concordance" cosmological model that states that 70% of ...
Jan. 31, 2006 Theresa Lynn, Caltech
Ultra-High Energy Cosmic Rays: The Mystery of Nature’s Most Powerful Particle Accelerators

Stargazing is perhaps one of humanity’s oldest pastimes. As modern astronomers have learned to image the universe in wavelengths across the electromagnetic spectrum, each added picture has answered old questions and uncovered new wonders.

In recent years a few observatories have concentrated on very different messengers from the cosmos: subatomic particles called cosmic rays which reach us from as nearby ...

Jan. 24, 2006 Martin Madsen, University of Michigan
Experimental Quantum Mechanics: Exploring the Quantum World One Atom at a Time
"Atoms on a small scale behave like nothing on a large scale, for they satisfy the laws of quantum mechanics," observed Richard Feynman, one of the most brilliant physicists of the 20th century. We can now explore the unusual behavior of a single atom through the combination of an electrical trap and lasers that enable us to isolate and control ...
Jan. 17, 2006 Erik Helgren, University of California at Berkeley
Optical Properties of Disordered Systems: Terahertz Spectroscopy of Doped Silicon
The terahertz (THz) spectral range has been under-utilized in the past both in fundamental research as well as in commercial applications. This spectral range is extremely important for studying condensed matter systems because the photon energy associated with THz frequencies is sub-meV, a typical energy for correlated electron physics; for instance this energy corresponds to the Cooper pair binding energy ...
Nov. 28, 2005 Douglas Osheroff, Stanford University
The Discovery of Superfluid :mil:`\mathrm{He}^3` as Seen Through the Eyes of a Graduate Student
It was at the beginning of his fifth year of graduate study that Douglas Osheroff discovered evidence for the existence of two unexpected phase transitions in a mixture of liquid and solid He3, both within three thousandths of a degree of absolute zero. The speaker will describe this event, and give his personal account of the excitement and confusion that ...
Nov. 15, 2005 David Awschalom, University of California at Santa Barbara
Spintronics, Semiconductors, Molecules, and Quantum Information Processing
There is a growing interest in exploiting electronic and nuclear spins in semiconductor nanostructures for the manipulation and storage of information in emergent technologies based upon spintronics and quantum logic. Such schemes offer qualitatively new scientific and technological opportunities by combining elements of standard electronics with spin-dependent interactions between electrons, nuclei, electric and magnetic fields. Here we provide an overview ...