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
March 23, 2010 Thomas Helliwell, Harvey Mudd College
Dark Energy and Einstein’s Biggest Blunder
According to quantum field theory, vacuum is not nothing, but probably contains an enormous amount of energy. A primary effect of this energy should be on gravitation on a cosmological scale. In fact, in 1917 Einstein introduced something very similar into his gravitational field equations, the so-called “cosmological constant”, to overcome what he thought was a flaw in the equations. ...
March 2, 2010 Kai-Mei Fu, Hewlett Packard Labs
Optical Spintronics for Quantum Information Processing and Magnetic Sensing
The optical detection and control of solid-state spins has exciting applications in the fields of quantum information processing and magnetic sensing. In the first part of the talk I will show how optical pulses can be used to measure the three fundamental relaxation times of electrons bound to donors in GaAs: population relaxation \( T_1 \), inhomogeneous dephasing \( T_2^* ...
Feb. 16, 2010 Matthew Rakher, National Institute of Standards and Technology
Quantum Optics with Quantum Dots
The quantum mechanical nature of single atoms or molecules can be very difficult to measure in the laboratory. However, recent progress using atomic-like, solid-state systems has made such measurements more accessible. In particular, the semiconductor quantum dot (QD) has developed into a widely-used platform for conducting experiments at the intersection of quantum optics and condensed matter physics. Combined with nanofabrication ...
Feb. 9, 2010 Gerardo Dominguez, University of California at San Diego
Isotope Studies in Natural Systems and Their Applications
The abundance of isotopes of an element can vary as a function of time and space. A thorough understanding of the physical and chemical factors that underlie these variations can be used to reconstruct the natural history of the Earth, the planets, and even the interstellar medium. In this talk, I will discuss factors that lead to small but measurable ...
Feb. 2, 2010 Alexander Sushkov, Yale University
Why Does the Universe Have More Matter than Anti-matter? A Search for Violation of Parity and Time-reversal Symmetries
Last year’s Nobel Prize in physics was awarded to Nambu, Kobayashi, and Maskawa for their study of nature’s broken discrete symmetries (charge conjugation C, parity P, and time reversal T). However, what we know about the breaking of these symmetries is not enough to explain the apparent matter-antimatter asymmetry of the universe. One of the ways to study the breaking ...
Jan. 26, 2010 Igor Teper, Stanford University
Cavity-Aided Quantum Measurement and Dynamics with Cold Atoms
The exquisite control of internal and external degrees of freedom possible for laser-cooled atoms makes them ideal test particles for the study of a wide variety of physical effects. One of the most promising frontiers of research in atomic clocks and sensors is quantum metrology, the engineering of quantum states to improve sensor performance (i.e. using quantum mechanics to beat ...
Nov. 10, 2009 David Garofalo, Jet Propulsion Laboratory
Does the Universe Know About Black Hole Spin?
The cosmic evolution of active galaxies is influenced by their tiny central regions where the most energetic steady outflows of matter and energy in the known universe are produced. The paradigm that has emerged for these powerful engines involves an interaction between magnetized accretion flows and rotating supermassive black holes. I describe recent work according to which the power produced ...
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, ...