25 (Thursday) 4:35 pm
Title: Detecting Gravitational Waves from Supermassive Black Hole Binaries
Abstract: Gravitational waves (GW) have never been directly detected, and the ability to do so will revolutionize astrophysics. In particular, we will be able to directly observe GW radiation from some of the most extreme events in the universe. Astronomers worldwide are involved in an effort to directly detect GWs using millisecond pulsars located throughout our Galaxy. I will review the basic principles of operation and the status of this effort. Our contribution at Oberlin focuses on correcting the pulsar signal for its passage through non-empty interstellar space. I will highlight some of our recent results, including work done with the Dutch LOFAR telescope this past year.
8 (Wednesday) 4:35 pm
Title: Integrating Intermittent Renewable Generation on Bulk Electric Systems
Wind and solar generators are often called variable or intermittent sources as their output is dependent on the availability of wind and sun. Electric power system operators face a challenge in smoothly integrating the variable output from wind and solar generators with existing sources and sinks on the grid without compromising power quality, reliability, or the infrastructure of the system. Operators must continuously match output from many electric generators (sources) to electricity demand at many end-use sites (sinks), a process that becomes more difficult with high levels of unpredictable and/or undispatchable sources.
Over the last five years, as wind and solar generators have become a more significant fraction of available generating capacity in many regions of North America, this challenge has driven development in generation technology, storage technology, forecasting tools, and coordination among system operators.
6 (Thursday) 4:35 pm
Abstract: General relativity presents a radical restructuring of our concepts of space and time, a restructuring that even the most fanciful science fiction often has a difficult time capturing. The upcoming film Interstellar, directed by Christopher Nolan and co-produced by theoretical physicist Kip Thorne, was designed to capture this radically new (yet century old) picture of spacetime in a scientifically accurate way. In this talk, I'll describe some of the surprising features of general relativity that promise to find their way into this blockbuster movie, and a few of the technical challenges inherent in visualizing these features accurately, even with state of the art computer graphics.
4 (Thursday) 4:35 pm
Abstract: Maxwell's demon cannot achieve a violation of the Second Law of thermodynamics because of the thermodynamic cost of information erasure (known as Landauer's principle). This suggests a new statement of the Second Law, one that is provably equivalent to more familiar versions: No process can have as its sole result the erasure of information. The connection between information and thermodynamics is made even stronger by some recent theorems in non-equilibrium statistical mechanics. The amazing Jarzynski identity, which governs the amount of work done in a non-equilibrium process, can be generalized in a natural way to encompass processes that either acquire or dispose of information. Numerical experiments confirm this new information identity.
9 (Monday) 4:35 pm
Abstract: The North American Nanohertz Observatory for Gravitational Waves, the Parkes Pulsar Timing Array, the European Pulsar Timing Array, and the combined International Pulsar Timing Array (IPTA) all use millisecond pulsar (MSP) observations to search for the presence of gravitational waves (GWs). On behalf of the IPTA we conducted a 24-hr, nine-telescope observing campaign on millisecond pulsar J1713+0747 (Dolch & Lam et al. 2014) in order to establish the ultimate timing precision of MSPs, as well as to produce non-detection upper limits at higher GW frequencies than those usually studied by pulsar timing. We then report on recent and upcoming observations of optical bow-shock nebula around radio pulsars. These data can also lead to a better understanding of MSP timing precision. Improved timing precision helps our chances of detecting GWs originating from sources such as cosmic strings and, most prominently, merging supermassive black holes.
10 (Tuesday) 4:35 pm
Title: High Temperature Superconductivity: Taming Serendipity
Abstract: As we pass the centenary of the discovery of superconductivity, the design of new and more useful superconductors remains as enigmatic as ever. As high-density current carriers with little or no power loss, high-temperature superconductors offer unique solutions to fundamental grid challenges of the 21st century and hold great promise in addressing our global energy challenge in energy production, storage, and distribution. Traditionally guided by serendipity, researchers in the field have grown into an enthusiastic global network to predictively design new superconductors. I will share our general guidelines; and
some specifics we are following in this direction, and strive to convey
the renewed passion we share in this international pursuit.
19 (Thursday) 4:35 pm
Title: Macro Dark Matter
Abstract: Dark matter is a vital component of the current best model of our universe, Lambda-CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. I will discuss the general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and square centimeters, respectively -- we refer to these macroscopic candidates as Macros. Such dark matter objects could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. I will discuss the earth-based, astrophysical, and cosmological observations used to constrain part of the Macro parameter space. Large regions remain unconstrained, however, most notably for nuclear-dense objects with masses in the range between about 50 - 10^17 and 10^20 - 10^24 grams.
14 (Tuesday) 4:35 pm
Title: Examining the Mechanics of Dynamic Microtubule Networks
Abstract: Cells utilize dynamic biopolymer networks to carry out mechanical tasks during diverse processes such as cell division, migration, and development. For example, the microtubule-based mitotic spindle performs the physical work of segregating duplicated chromosomes into two daughter cells. The components that make up these networks are not typically at equilibrium, but instead operate under load. It has been challenging to understand how the forces that move microtubules and chromatin are regulated within these micron-sized networks by ensembles of nanometer-sized proteins.
Forth will present his postdoctoral work that directly addresses these problems by employing single molecule biophysical methods, including optical trapping and TIRF microscopy. His work reveals that proteins involved in cell division can generate frictional resistance as they move along microtubules, and that this friction can be harnessed within spindles to help ensure successful DNA segregation. These results can help us link the biophysical properties of essential proteins with their function in dividing cells.