Colloquium

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. 27, 2009 Everett Lipman, University of California at Santa Barbara
Tracking the Motion of a Biomolecular Machine with a Nanoscale Optical Encoder
Molecular motors are essential components of the machinery of life, enabling processes such as DNA replication, transcription, and repair, protein synthesis, and muscle movement. In order to understand the details of how they function, it is necessary to track one at a time, a task that is complicated by the disparity between their sizes (about 5 nm) and the resolution ...
Oct. 6, 2009 Janet Scheel, Occidental College
Go With the Flow: Numerical Simulations of Turbulence in Fluids
Turbulent systems are all around us, from waves crashing on our beaches, to smoke rising from the fires in our mountains, to the air that makes our airline flights bouncy and sometimes downright frightening. Turbulent systems are not well understood. Rayleigh-Benard convection is a more simplified system which captures some of the key features of turbulence, including thermal plumes and ...
Sept. 22, 2009 Ann Esin, Harvey Mudd College
The Early Lives of Sun-Like Stars
The study of star formation is currently one of the most active areas of astrophysics, partly due to its connection with the origin of planetary systems. Because young proto-stars tend to be heavily embedded in gas and dust clouds, detailed imaging of these objects during early critical stages of evolution is very difficult, which makes testing theoretical models of stellar ...
Sept. 8, 2009 Several HMC Physics Majors, Harvey Mudd College
Summer 2009 Off-Campus Research
We will hear from Nicole Crisosto, Greg Harding, Hong Sio, David Miller, Cecily Keppel, Trystan Koch, Alex Hagen, Bonnie Gordon, Arthur Eigenbrot, and Alyssa Dray
April 14, 2009 Mike Campbell, Logos Technologies
A Sustainable Nuclear Energy Future
The development of a sustainable, abundant, environmentally and socially acceptable global energy supply is the most pressing challenge of the 21st century. The magnitude and importance of the challenge to supply the world with the tens of terawatts of such power dictate that the solution, despite those who advocate for any single approach, will consist of multiple energy sources — ...
March 31, 2009 Anyes Taffard, University of California at Irvine
LHC — Journey to the Heart of Matter
The start-up of the newest and most powerful particle accelerator has started. The Large Hadron Collider (LHC) is the most ambitious undertaking ever attempted in Physics. The scale and complexity of this undertaking are so large it required a truly global effort to realize. The LHC will permit exploration of the fundamental nature of matter and forces by creating conditions ...
March 10, 2009 Peter Taborek (’74), University of California at Irvine
Singularities in Fluid Flows from Superfluids to Bubbles to Chicken Soup
Fluids can form droplets that pinch off from each other in many situations ranging from ink jet printers to the kitchen sink. The phenomena that occur a few microseconds from pinch-off involve a balance of surface tension forces, inertia, and viscosity. Droplet pinch-off is an example of a nonlinear phenomenon that leads to finite time power law singularities and striking ...
Feb. 24, 2009 Oskar Painter, Caltech
Nano-opto Mechanics: Utilizing Light Forces Within Guided-Wave Nanostructures
The fact that light carries momentum and can exert a mechanical force was first proposed by Kepler and Newton. The interaction of light with sound waves, in the form of Brillouin and Raman scattering, has been known since the 1920s and has many practical applications in the fields of spectroscopy and optoelectronics. With the advent of the laser in 1960s, ...
Feb. 10, 2009 Roland Kawakami, University of California at Riverside
The Anatomy of a Spintronic Device
Since its inception, solid-state electronics has relied on the charge degree-of-freedom to store and process information. With the 1988 discovery of giant magnetoresistance and its remarkable impact on hard-drive technology, the question has turned to whether it is possible to utilize the spin degree-of-freedom in semiconductor electronics for superior performance in some aspect (e.g. speed, power, function, etc.). Although there ...
Jan. 27, 2009 Jenny Hoffman, Harvard University
Exploring a New Family of High-:mil:`T_c` Superconductors: the Iron-Arsenides
I will give a review of superconductivity research over the last century, culminating in the recent, exciting discovery of a second family of high-\( T_c \) superconductors based on iron and arsenic. We are now studying these new superconductors using a low temperature scanning tunneling microscope (STM), built with the help of two Harvey Mudd alums, now graduate students at ...
Dec. 2, 2008 Warren Rogers (’81), Westmont College
The Study of Exotic Nuclei and its Application to Astrophysical Systems
Some of the most interesting questions in nuclear physics research today deal with understanding the creation of the elements in the periodic table in explosive astrophysical systems. Elements that are not created by the "slow" stellar nucleosynthesis S-process are thought to be created by the very rapid and less well understood R- and RP-processes. Our research program at the National ...
Nov. 11, 2008 Ned Wright, University of California at Los Angeles
Observing the Origin of the Universe
In the past century our knowledge about the Universe went from one fact - the sky is dark at night - to hundreds of facts from the Cosmic Microwave Background, observations of distant supernovae, and baryon oscillations.

We now know the Universe is so big that we can see nearly all the way back to the origin of the Universe ...

Oct. 28, 2008 Alex Small, Cal Poly Pomona
Faster, Smaller, Smarter: Using Light to See Things Smaller than the Wavelength of Light!
Standard microscopes cannot resolve features smaller than the wavelength of light, due to diffraction of light by the microscope aperture. This same phenomenon also limits the features that can be formed in conventional photolithography. In recent years, several techniques have been proposed for beating the diffraction limit in fluorescence microscopy, enabling the detection of cellular features down to 30 nm ...
Oct. 7, 2008 Jerry Pine, Caltech
Studying the Development of Cultured Neural Networks
Brain neurons can be dissociated from embryos and grown in culture dishes, where they form functionally connected neural networks. The details of this development can be studied in small cultures, where all the connections can be mapped by stimulating individual neurons and observing the responses of all others. A new technology that permits this to be done nondestructively over time ...
Sept. 23, 2008 Nicola Spaldin, University of California at Santa Barbara
How Do We Use Computational Methods to Design New Materials?
Modern computational methods are proving to be invaluable in the first-principles design of new materials with specific targeted functionalities. After discussing the capabilities and limitations of available computational tools, I will illustrate their utility with a case study on materials that are simultaneously ferromagnetic and ferroelectric. Such “multiferroics” are of current interest because coupling between the order parameters leads both ...