Department of Physics
University of Oregon

Sense-making in physics involves translating non-mathematical understanding into conceptualized mathematics, and formal mathematical statements into narrative explanations.
These processes, referred to as mathematization, have been studied in mid- to upper-level undergraduate physics courses (Bing & Redish, Sherin).
Successful students actively attribute meaning to equations and generate mathematical relationships to describe physical situations.
This mathematical understanding becomes integral to their physics knowledge.
Mexico State University, we seek to promote mathematization in the much larger population of high school and college students in introductory physics.
Unlike the successful upper level students, these students tend to view math in physics as a process of memorizing and mastering algorithms, devoid of creative and generative power for building understanding.
Increasing the frequency and quality of student mathematization is a desired outcome of our introductory courses, but there is strong evidence that this is generally not realized for most students.
To explicitly teach mathematization, we are developing curricular materials and methods based on invention instruction. Invention tasks serve as preparation for an initial exposure to the use of math in a variety of physics contexts.
Through creative thinking and struggle, students construct mathematically sensible ways to characterize physical situations and reason numerically about them.
Because socioeconomically disadvantaged school districts often have weak mathematics programs in the middle and high school levels, these invention tasks may be particularly beneficial to students from some underrepresented groups. In coordination with the development and testing of instructional materials, we are formulating assessments to measure student reasoning about the proportional relationships ubiquitous in introductory physics.
We present early results on this work with mathematically underprepared students as well as mainstream students.


This work is supported by NSF DUE-1045227,
NSF DUE-1045231, and NSF DUE-10452

Water is a rather important liquid to most of us. All of biology and most of chemistry involves interfaces with water, and yet aqueous interfaces continue to present a challenge to understand theoretically. I will introduce the structure of liquid water, and will present a new method using classical density functional theory for treating aqueous interfaces.

Quantum mechanics is our most successful theory, yet its conceptual
foundations and interpretation are as hotly debated as ever. A central
question is the meaning of quantum states ("wave functions"). Quantum
states predict only probabilities of what we will find in a
measurement, yet quantum states are also said to be a complete
description of the physical state of a system. So, are quantum states
just calculational tools, or do they represent physical properties? A
recent theorem has made big waves by claiming that to avoid
contradictions with the predictions of quantum mechanics, quantum
states must be real. I will show that while the theorem does establish
something interesting, its conclusion is too hasty and its sting
easily pulled.

M. Schlosshauer and A. Fine, "Implications of the
Pusey–Barrett–Rudolph quantum no-go theorem," Phys. Rev. Lett. 108,
260404 (2012).

Quantum mechanics has been formulated over hundred years ago and many experiments have supported this extraordinary theory. It remains however unclear how quantum mechanics can be combined with general relativity in a 4 dimensional space-time structure. Furthermore the emergence of the classical world from the underlying quantum mechanics, often discussed in connection with the collapse of the quantum wavefunction, leaves open questions. Prof. R. Penrose has been one of the leading theorists in the past 50 years who addressed these fundamental issues. I will discuss some of his ideas leading to far reaching predictions that could be tested in experiments. In particular I will discuss two quantum optomechanical experiments that are designed to test the notion of quantum superpositions for macroscopic objects. The goal is to bring a tiny optical mirror into a quantum superposition and to investigate its decoherence. An essential aspect of the experiments is to perform optical cooling to the quantum ground state of a low frequency resonator.

The last few years have seen a paradigm change in (scanning) transmission electron microscopy ((S)TEM) with unprecedented improvements in spatial, spectroscopic and temporal resolution being realized by aberration correctors, monochromators and pulsed photoemission sources. Spatial resolution now extends to the sub-angstrom level, spectroscopic resolution into the sub-100meV regime and temporal resolution for single shot imaging is now on the nanosecond timescale (stroboscopic imaging extends this even further to femtoseconds). The challenge now in performing experiments in an (S)TEM is to implement the in-situ capabilities that will allow both engineering and biological systems to be studied under realistic environmental conditions. Performing experiments using in-situ stages or full environmental microscopes presents numerous challenges to the traditional means of analyzing samples in an electron microscope – we are now dealing with the variability of dynamic process rather than a more straightforward static structure. In this presentation, I will discuss the recent developments in the design and implementation of in-situ stages being pursued at the Pacific Northwest National laboratory (PNNL). Examples of the use of these capabilities for the direct imaging of oxidation and reduction in metals, ceramics and catalytic systems and to identify the fundamental processes involved in nucleation and growth of nanostructures from solution will be presented. As the in-situ stages have been designed to be incorporated into both high spatial resolution aberration corrected (S)TEM as well as into high temporal resolution Dynamic TEM (DTEM), the potential for future experiments to study dynamics, including those in live biological structures, will also be discussed.

Collision events at the Large Hadron Collider (LHC) are dominated by jets — collimated sprays of particles arising from the fragmentation of underlying quarks and gluons. Jets are a crucial probe of possible new physics beyond the standard model, but the high energy and high luminosity of the LHC pose serious challenges for precision jets studies. In this colloquium, I will report on recent advances in using jet substructure to maximize the discovery potential of the LHC. These advances include new methods to extract properties of the Higgs boson, new observables to identify boosted resonances from high energy collisions, and new insights into the physics of hadronization.

DNA has proven to be a versatile tool for arranging and manipulating matter on the nanoscale. I will describe work that I have been involved in that uses DNA to make molecular motors and active materials as well as to arrange nanoscale components into devices.