Seminars and Colloquia
Unless otherwise noted, all physics seminars and colloquia are held on Tuesdays from 4:45 to 6:00, in lecture room 3 of Merrill Science Center. Tea and snacks will be served before seminars at 4:15 in 204 Merrill. If you would like to be mailed seminar announcements, please send an email to Ellen Feld.
Contact colloquium organizer Jonathan Friedman with any questions about colloquia.
Tue, Sep 15, 2015
Tue, Sep 22, 2015
"Waves, Currents, Beaches, and All That: Fluid Dynamics of the Coastal Ocean"
How do ocean waves, currents, and coastlines evolve and interact? The answer lies in the fascinating dynamics of the coastal ocean: wind-generated ocean waves refract, steepen, and break as they enter shallow water, drive strong currents, transport sand, and change the shape of the beach. Improving our understanding of these processes is essential to making better predictions of flooding and erosion during storms like Hurricane Sandy. I’ll describe a set of experiments in which we “perturbed” the seafloor by dredging big holes and channels underwater at the beach, then studied the response to learn about the feedbacks between waves, currents, and seafloor change. The field observations, combined with theory and numerical simulations, reveal how gravity smooths out sandcastles and sandbars, and why rip currents turn on and off.
Tue, Sep 29, 2015
"Experimental Studies in 1D Quantum Magnetism: Old Physics, New Materials, New Physics"
Quantum physics is the study of the behavior of nature at very small length scales, atomic size and smaller. The explosive development of nanoscience over the past thirty years enables people to synthesize, manipulate, image, and control very small materials.
This presentation will offer a different perspective. Quantum behavior can also be studied and understood using appropriately-designed macroscopic materials. This premise will be illustrated by recent developments in one-dimensional magnetism in which magnetic behavior is dominated by purely quantum effects.
Today - Tue, Oct 6, 2015
"Does the Big Bang Prevent Us from Being in Two Places at Once?"
Quantum mechanics tells us that atoms and even molecules can display both particle-like and wave-like properties. By wave-like properties, we mean for example that an atom can be in two different places at once. Only when we probe the atom does its position "collapse" into having one value or the other, and we have no way of knowing beforehand which value it will be. However, there is nothing in the theory of quantum mechanics that rules out larger objects, such as a ball or even you, being in two places simultaneously. So why don't we observe everyday objects in such bizarre quantum states? We shall argue that the answer may ultimately lie in the presence today of a largely invisible, leftover remnant from the Big Bang that created our Universe.
Tue, Oct 13, 2015
"Atomic Sensors for Precision Measurements"
Modern atomic physics techniques use lasers to interact with and manipulate atoms in a gas. Quantum mechanics predicts atomic structure to high precision and demonstrates that atoms of the same species are truly identical. These features provide an attractive platform for the use of atoms as sensors for a variety of fundamental and applied precision measurements. I will describe a fundamental symmetry test using warm atomic vapors of interacting K and 3He that set new limits on a Lorentz-violating background field interacting with the neutron spin. I will also describe instrument development of a novel atom interferometer in an optical cavity using Cs atoms in a cold atomic gas. Such an apparatus could be used for proposed fundamental gravity tests for use in inertial navigation without the aid of GPS.
Tue, Oct 20, 2015
Tue, Oct 27, 2015
Tue, Nov 3, 2015
Tue, Nov 10, 2015
Tue, Nov 17, 2015