## 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.
 Sept. 21, 2010 Nine HMC Physics Majors, Harvey Mudd College Summer 2010 Off-Campus Research Kali Allison, John Bremseth, Theo DuBose, John Grasel, Robert Hoyt, Cecily Keppel, Kyle Luh, Shaun Pacheco, and Susanna Todaro describe their summer research experiences. Sept. 7, 2010 Peter Saeta, Harvey Mudd College Physics and Engineering in the Village Are you tired of having your work appreciated? Does it embarrass you when people celebrate your achievements by cheering, singing, and dancing? Yes? Well, then I don’t recommend working on a water and solar-power project in Africa. Engineering students Rob Best (’10), Isabel Bush, Evann Gonzales, Ozzie Gooen (all ’12) and I spent 6 weeks installing photovoltaic panels, a solar-powered ... April 20, 2010 John Armstrong (’69), Jet Propulsion Laboratory Doppler Tracking, Pulsar Timing and the Sensitivity of Low-Frequency Gravitational Wave Searches Gravitational waves (GWs) are predicted across a spectrum ranging from ~kilohertz to femtohertz. Gravity wave detections and subsequent detailed waveform study will give information on astrophysical sources unavailable with any other method. The GW spectrum divides into Fourier bands, depending on detector technology. In the low-frequency (~millihertz) and very-low-frequency (~nanohertz) bands, detectors involve spacecraft Doppler tracking and pulsar timing, respectively. ... April 6, 2010 Several HMC Professors, Harvey Mudd College Recent Developments in Physics The Wilkinson Microwave Anisotropy Probe — Ann Esin Direct Evidence for Dark Matter — Ann Esin Quantum Teleportation — Theresa Lynn Negative Index of Refraction Materials — Peter Saeta 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