Edward “Joe” Redish, University of Maryland
Reinventing Introductory Physics for Life Scientists (IPLS)
A two-term class in physics has been a staple of the education of life scientists for many years. At many large universities life-science students have become a dominant element in this course, their numbers surpassing the number of engineers taking physics. In addition, the biology and medical school communities have begun calling for a more sophisticated and biologically oriented curriculum, one stressing the building of generalized scientific competencies and taking a more interdisciplinary perspective.
A multi-disciplinary team of scientists centered at the University of Maryland (UMd) has been reinventing the IPLS course as part of the National Experiment in Undergraduate Science Education (NEXUS). Since life science students have an immense diversity of potential careers, we focus on the common elements of biology curricula: molecular and cellular biology together with building general scientific competencies accessible in introductory physics, such as mathematical modeling, reasoning from core principles, and multi-representation translation. The class is positioned as a second-year class with prerequisites that include calculus, chemistry, and biology. This lets us discuss atomic and molecular examples from the first and include lessons with authentic biological value. In addition to building the basic ideas of the Newtonian framework, electric currents, and optics, NEXUS/Physics includes a significant effort on atomic interactions and chemical bonding, random motion and diffusion, thermodynamics (including entropy and free energy), and spectroscopy. These elements are integrated into laboratories as well as into the lecture part of the class. An important aspect of our development is a strong collaboration between the Physics Education Research and Biophysics Research groups at UMd, permitting a combination of cutting-edge biophysics research with front-line pedagogy. While in development, materials are publically available on the web for observation, use, and comment.
 Scientific Foundations for Future Physicians (AAMC & HHMI, 2009);
Vision and Change in Undergraduate Biology Education: A call to action (AAAS 2009);
BIO 2010: Transforming Undergraduate Education for Research Biologists (NRC 2011)
 NEXUS/Physics: An interdisciplinary repurposing of physics for biologists, E. F. Redish, et al., Am. J.Phys 82:5 (2014) 368. [http://arxiv.org/abs/1308.4947]
Ray Frey, University of Oregon
State of the Physics Department and Gamma-Ray Bursts
Dean Karlen, University of Victoria and TRIUMF
T2K: Investigating Nature’s Ghostly Particles, The Neutrinos
Host: Jim Brau
Abstract: T2K is the name of an experiment in Japan that has been studying the most mysterious of fundamental particles – the neutrinos. An intense beam of neutrinos are sent through the ground towards the gigantic SuperKamiokande detector, almost 200 miles away. Some of the neutrinos interact inside the detector and reveal a change in their identity. These measurements have established that there is complete mixing of the three kinds of neutrino. More data from T2K and other neutrino experiments will be collected in years to come to look for differences between neutrinos and anti-neutrinos, in order to ascertain whether neutrinos could be responsible for the missing anti-matter in the Universe.
Vera Luth, SLAC National Accelerator Laboratory
Observation of Time Reversal Violation in B Meson Decays
Host: Dietrich Belitz
Abstract: While discrete symmetries and conservation laws are basic concepts of physics, the search for broken symmetries has been a very interesting topic for both experimentalists and theorists. In particle physics, the violation of charge conjugation and parity in weak interactions was observed 60 years ago, and CP violation was found to be violated in neutral kaon decays and more recently in B mesons. It has been much more difficult to detect the violation of time reversal at the microscopic level. The BABAR Collaboration has recently found first and very convincing evidence for T Violation in neutral B mesons. The result is consistent with equal CP and T violation and with CPT invariance.
Kelly Miller, Harvard
Physics Education Research and Practice; From Lecture Demonstrations to the Flipped Classroom
Host: Stan Micklavzina
Abstract:This talk will discuss both recent research on the efficacy of physics lecture demonstrations as well as the implementation of a “flipped class” in the context of introductory physics curricula. Research has shown that roughly one out of every five observations of a demonstration is inconsistent with the actual outcome. Furthermore, correct observation of a lecture demonstration appears to be related to how well a student understands the underlying physics concept before being shown the demo. These findings, as well as the role of prediction-making in demonstration pedagogy will be discussed in more detail.
Recent trends towards flipped classrooms raise interesting questions regarding the teaching of physics to large introductory classes. The implementation and logistics of Applied Physics 50, a new flipped, ‘studio style’ physics class at Harvard, will be discussed. This course combines best practices to deliver a learning experience that helps students develop team and problem solving skills as well as a solid conceptual understanding of physics.
Alan Petersen, Spectra Physics
Review of Diode-Pumped Alkali Vapor Lasers
Host: Bryan Boggs
Since its first demonstration about 10 years ago, the diode-pumped alkali vapor laser (DPAL) has occupied a unique, sometimes controversial position within the laser field. Originally conceived as large aperture, CW brightness converter for materials processing and directed energy applications these systems have also been pursued as potential short wavelength sources and have stimulated renewed interest in relevant gas phase atomic physics and solid state materials technology. In this talk I will present the DPAL concept, summarize some early experiments including our own, and consider the challenges to high average power realization.
Sarah Ballard, University of Washington
Directions to the Nearest Alien Earth-like Planet: Walk from Here to Knight Library
Host: Jim Brau
Abstract: The landscape of exoplanet science has been dramatically reshaped since the launch of NASA’s Kepler mission in 2009. While the mission’s primary science driver was to uncover the frequency of Earth-like planets orbiting Sun-like stars, in fact the vast majority of rocky planets in their stellar habitable zones reside in very different environments. M dwarf stars, half the mass of the Sun and smaller, host most of the galaxy’s terrestrial worlds. The small stature of these stars, the most prolific type in the universe, render exoplanet detection and characterization easier for upcoming missions. However, they furnish very different conditions for life than have nourished it on Earth. I’ll summarize the key findings of what Kepler has revealed about planet occurrence, and how it informs our search for signatures of life on other planets.
Walt Ogburn, Kavli Institute for Particle Astrophysics and Cosmology, Stanford
BICEP2 and The Echoes of Cosmic Inflation
Host: Jim Brau
The BICEP2 team has announced the detection of degree-scale B-mode polarization of the CMB, consistent with the imprint of inflationary gravitational waves created an instant after the big bang. The telescope is a compact refractor with a 26 cm aperture and 512 antenna-coupled TES bolometers observing at 150 GHz (2 mm). BICEP2 observed from the South Pole for three seasons from 2010 to 2012. A low-foreground region of sky with an effective area of 380 square degrees was observed to a depth of 87 nK-degrees in Stokes Q and U. We have just announced an excess of B-mode power over the base lensed-LCDM expectation in the range 30<l<150, inconsistent with the null hypothesis at a significance of >5σ. The observed B-mode power spectrum is well fit by a lensed-LCDM + tensor theoretical model with tensor/scalar ratio r=0.20+0.07-0.05, with r=0 disfavored at 7.0σ.
Jeff Lundeen, University of Ottawa
Seeing is Believing: Direct Observation of a General Quantum State
Host: Michael Raymer
Abstract: Central to quantum theory, the wavefunction is a complex distribution associated with a quantum system. Despite its fundamental role, it is typically introduced as an abstract element of the theory with no explicit definition. Rather, physicists come to a working understanding of it through its use to calculate measurement outcome probabilities through the Born Rule. Tomographic methods can reconstruct the wavefunction from measured probabilities. In contrast, I present a method to directly measure the wavefunction so that its real and imaginary components appear straight on our measurement apparatus. At the heart of the method is a joint measurement of position and momentum that is made possible by weak measurement (a concept that I will attempt to demystify). I will describe an experimental example of the method in which we directly measured the transverse spatial wavefunction of a single photon. New experimental work extending this to mixed states will be presented as well. Our direct measurement method gives the wavefunction a plain and general meaning in terms of a specific set of operations in the lab.
Nature, 474, 188 (2011). http://arxiv.org/abs/1112.5471
Phys. Rev. Lett. 108, 070402 (2012). http://arxiv.org/abs/1112.3575
Physical Review Letters, 112, 070405 (2014). http://arxiv.org/abs/1309.1491
Alex Small, Cal State Panoma
Host: Raghu Parthasarathy
Theoretical Limits to Superresolution Fluorescence Microscopy
Superresolution microscopy techniques enable fluorescence imaging of biological specimens with sub-wavelength resolution, down to as low as 10 nanometers in some cases. Interestingly, in essentially all techniques considered thus far, the resolution scales as the wavelength of light divided by the square root of some measure of the number of photons used. We have developed a proof that the relationship between image resolution and measures of photon count has a universal 1/sqrt(photon count) scaling for very wide classes of superresolution techniques. Additionally, we have developed a theoretical framework for benchmarking the performance of the algorithms used to analyze the images, and have developed fast image analysis algorithms and mathematical approaches for optimizing image acquisition.