Events at Physics |
Events During the Week of February 14th through February 21st, 2010
Sunday, February 14th, 2010
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 1:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 4:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
Monday, February 15th, 2010
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Electron Gyroscale Fluctuations in the National Spherical Torus Experiment
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: David Smith, UW-Madison Dept of Engineering Physics
- Plasma Theory Seminar
- Kinetic Theory of Instability-Enhanced Collective Interactions in Plasmas
- Time: 4:00 pm
- Place: 514 ERB
- Speaker: Scott Baalrud, CPTC
Tuesday, February 16th, 2010
- Chaos & Complex Systems Seminar
- Title to be announced
- Time: 12:05 pm
- Place: 4274 Chamberlin Hall
- Speaker: Mike Arnold, UW-Madison, Dept. of Material Science and Engineering
- Astronomy Colloquium
- A Life for Stars
- Time: 3:30 pm - 5:00 pm
- Place: 3425 Sterling Hall
- Speaker: Alexander Heger, University of Minnesota - Twin Cities
- Abstract: A few hundred thousand years after the Big Bang the primordial gas recombined, became transparent - the last light from that we now see as Cosmic Microwave Background. There was very little structure in the universe at that time, no source of light - we call it now the Cosmic Dark Ages. It would take several hundred million years before the first stars in the universe would form, making the first source of light after the big bang, when the "dark" matter could clump, collecting up baryonic matter that could cool down, and condense into the first stars. Still, the gas was quite warm, so it would take massive, big clouds to collapse under their own gravity, making big stars. At least, this is what out best theories tell us. But no one actually has ever observed this to date. So, is that story true? How big were the first star actually? What can we do to find out? Looking at the current universe, we do see that some quite big stars are still formed today, but they shed mass in massive winds and in giant eruptions and will die not quite as big as they were born. Is the same true for the first stars if born as big as the biggest stars we see today? Or were there even bigger stars, and how would the evolve and die? Could these latter once be the predecessors of the super-massive black holes harbored in the centers of even some of the earliest galaxies we see? So, how can we find out? At least part of the story we may be able to uncover now by looking at ashes of the first stars, the pattern of elements that made and that were incorporated in subsequent generations of stars. Observes now have found some very old stars in the halo of our galaxy, one of its oldest constituents, that likely have formed very early in the universe. These stars have only minuscule traces of heavy elements, they almost exclusively consist of the matter made by the big bang. We now believe that many of those likely have been polluted; only by a few, maybe a single star. But the ratio of heavy elements that a star makes depends a lot on how massive is was, and how it died. So looking at the ashes of these first stars, as incorporated in the old stars we have found, may tell the story of the lives of those first stars. What will we discover?
- Host: Richard Townsend
Wednesday, February 17th, 2010
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
Thursday, February 18th, 2010
- R. G. Herb Condensed Matter Seminar
- From quantum electronics to quantum nanofluidics
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Guillaume Gervais, McGill University
- Abstract: It has long been known that the flow of electric charges in an electrical circuit maintained by a voltage drop is analogous to the fluidic mass flow in a pipe maintained under a pressure differential. In electronic devices, and at small scale, lowering the dimensionality can have drastic consequences on the flow of charges in electronic circuit. In two dimension, series of quantized states appear with quantized Hall resistance, competing with electron crystals and other many-body states. In one dimension, the conductance of a wire itself becomes quantized in unit of 2e^2/h due to confinement and quantum effects. In this talk, I will present an overview of recent results for the quantum electronics studied in ultra-clean semiconductor materials with an emphasis on possible non-abelian quantum states. I will also discuss our endeavour and progress to measure the mass flow of a quantum fluid confined into a nanopipe where, in analogy with the quantum electronics in one dimension, the conductance of the pipe should become quantized in unit of 2m^2/h.
- Host: Mark Eriksson
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- The Axis of Evil - Large Scale Anomalies in Maps of the CMB
- Time: 4:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Ted Bunn, University of Richmond
- Host: Timbie
Friday, February 19th, 2010
- Physics Department Colloquium
- Turning Photons into Polarized Nuclei
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Thad Walker, University of Wisconsin, Department of Physics
- Abstract: Spin-exchange optical pumping (SEOP) transfers the angular momentum of circularly polarized light to noble gas nuclei through a series of steps. First, an opaque vapor of alkali atoms (transmission~exp[-100]) is rendered nearly transparent by optical pumping into an atomic dark state with an efficiency of 1 photon per atom. Collisions between the alkali atoms are nearly spin conserving and produce a spin-temperature distribution with a temperature of about -0.06 K, or, in angular momentum units, -0.2 hbar. The highly spin-polarized atoms then transfer their angular momentum to noble gas nuclei through a weak hyperfine interaction occurring in binary collisions or formation of weakly bound van der Waals molecules. The cross sections for this process are tiny by atomic standards, 10^-24 cm^2, but this is compensated for by having an extremely large collision rate and long nuclear spin-relaxation times. According to these arguments, it should be possible to transfer angular momentum from laser light to nuclei with an efficiency of about 25%, producing >95% polarized nuclei. The resulting high density, hyperpolarized noble gas vapors are of considerable interest for medical imaging, spin-polarized targets, neutron spin-filters, and precision measurements. In practice, the performance of SEOP falls substantially below expectations. When Wisconsin entered the field in the mid '90s, the efficiencies were routinely much less than 1% and the polarizations in the mid 50%s. Through a series of experiments and technological developments, we have increased the efficiencies by an order of magnitude and produced polarizations as high as 80%. This colloquium will describe these experiments and their consequences.
Saturday, February 20th, 2010
- Physics Fair
- 3rd Annual Physics Fair - Open House
- Time: 11:00 am
- Place: Chamberlin Hall - Various Labs
- Speaker: Open House, University of Wisconsin - Madison
- Abstract: This is an open house in which members of the public can come to
learn about the research and teaching that are part of our department. The Physics Fair will include laboratory tours, hands-on demonstrations, activities for kids and families, and informal conversations with scientists. - Host: Hillary Stephens
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 1:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 4:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 7:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
Sunday, February 21st, 2010
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 1:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 4:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott