Physics Lecture Series | Spring 2012

Outreach activities of the Physics Department (UH Main Campus} include lectures, tours, one-day classes, workshops, research fellowships, teacher mentoring and training, competition events, and research equipment for students and teachers. We also visit about 60 schools (grades 1-12) in the Houston area. These activities are all aligned to not only inform and pique interest in Physics specifically and in science and technology in general; but also, to show students how Physics education undergirds and strengthens their college and career aspirations in fields as diverse as Business, Law, Teaching, Engineering, Medicine, and Science. We engage students in demonstrations that show the non-intuitive aspects of Physics and the power of that kind of knowledge. We show the simplicity of the few fundamental principles of Physics and how Physics can greatly improve "problem solving" skills of general utility. We believe that our outreach efforts influence many students to choose more challenging coursework in high school to prepare them for college and for their career aspirations.

Voted the greatest woman scientist ever by readers of The New Scientist. The world of science, technology and art celebrates 100 years anniversary of her Nobel Prize victory. The nations of Poland and France declared 2011 The Year of Maria Sklodowska Curie... The lecture will address Madam Curie's scientific accomplishments in the context of the social and political conditions of her time.

Pyroelectric materials are a special class of materials that generate an electrical response when heated and cooled. This talk will provide an introduction to the wide variety of identified pyroelectric materials and the associated pyroelectric response. The physics of the material including crystallographic behavior and polarity will be examined. The extraction and use of this pyroelectric response through circuit integration is detailed. Current applications will be presented with special consideration for the methodology of pyroelectric materials in energy conversion devices. A brief status of on-going related research will also be discussed.

The structural, electronic, and thermal properties of single-walled carbon nanotubes (SWCNTs) are very impressive, such that embedding them within materials holds the promise of creating nanocomposites with much improved characteristics over existing materials. Two-thirds of all SWCNTs are semiconducting and each exhibits a unique fluorescence spectrum. Using the method of fluorescence spectroscopy, embedded SWCNTs can be detected, individually or in bulk, and monitored in order to determine properties of the nanocomposite material such as quality of dispersion, alignment of nanotubes, and interactions between carbon nanotubes and the host. When strain is applied, a predictable shift in the fluorescence emission spectrum occurs for each (n, m) type of SWCNT. Experiments utilizing fluorescence spectroscopy aimed at dispersing carbon nanotubes within polymers without the aid of surfactants, attempts at alignment while curing, and the development of a novel strain-sensing nanocomposite will be discussed.

Most planets in our solar system have a global, quasistationary magnetic fields with large dipole components. In particular, the Earth's magnetic field has caused wonder and bafflement throughout history, and only in the last century have we come to a more realistic understanding of it. This talk will discuss solar system magnetism, historical background, and scientific research related to understanding the origins of planetary magnetic fields.

Ideal, incompressible, homogeneous, Hall magnetohydrodynamic (HMHD) turbulence may be investigated through a Fourier spectral method. In three-dimensional periodic geometry, the independent Fourier coefficients represent a canonical ensemble described by a Gaussian probability density. The canonical ensemble is based on the conservation of three invariants: total energy, generalized helicity, and magnetic helicity. Generalized helicity in HMHD takes the place of cross helicity in MHD. For real HMHD turbulence with dissipation, broken ergodicity and coherent structure are still expected to occur at low wave numbers, i.e. largest scales, where dissipation is least.

Orbital debris has become an increasing threat to low earth orbit utilization. The discussion provides a broad overview of environment modelling, measurements, mitigation efforts, reentry aspects, and spacecraft design implications.

Detection of extraterrestrial extra life in general, and of intelligent life in particular, would profoundly affect all aspects of human existence. It would fundamentally and forever change our perception of our place in the universe. Current searches for evidence of extraterrestrial life, as well as for evidence of extraterrestrial intelligent life, are both constrained and informed by the laws of physics. In this talk I will explore the approaches being taken in the wide variety of searches that are currently underway to determine whether Earth is the sole location of life in the universe.

Solar Proton Events (SPEs) are relatively rare occurrences when the Sun sends large numbers of energetic particles out into the heliosphere. Primarily protons with energies that can exceed 1GeV, these events can damage spacecraft, telecommunications satellites, and even Earth-based power grids, and can last from a few days to more than a week. Events appear to occur randomly over a 7 year period enveloped by the solar cycle. Since the advent of the modern space era, only a few hundred events have been observed. This talk will address various ways that can be utilized to assess SPE risk when working with such small sparse data sets.

Gamma-ray bursts are the most energetic events in the known universe. Though, since their discovery during the Cold War, an absolute explanation of their origin is still unknown. These cosmological, isotropic phenomena could be related to interaction of compact objects or related to supernovae explosions. The prompt GRB emission can often exhibit "multi-episodic" behavior; meaning they have several distinct, separated pulses. Using data from the Swift Observatory, this study attempts to gleam hints to the engine creating the high energy emissions from GRBs by measuring emission pulse episodes and quiet time durations in both the gamma-ray and x-ray bands and by searching for correlations in the gamma-ray emissions and the x-ray flares in the early burst afterglow.

Proteins and nucleic acids occupy the scale between the physicists' atom and the biologists' cell. These biomolecules can exist in a variety of states ranging from crystalline solid to disordered polymer. I will present the results of diffuse X-ray diffraction experiments which probe both the order and disorder parameters for protein molecules. Computer simulation of the dynamics of these systems also shows these molecules exhibit deterministic chaos.