This message is sent on behalf of Dr. Jan Cami of the Department of Physics and Astronomy:

On behalf of the Department of Physics & Astronomy, it is my pleasure to cordially invite you to witness and observe the 2012 Transit of Venusthat will happen next Tuesday, June 5^th, from ~6 p.m. until sunset (see poster attached).

Transits of Venus are truly rare events: the phenomenon has only been observed six times since Johannes Kepler first predicted a transit to occur in 1631, and the next one will happen only 105 years from now—in 2117! It is one of the few events that give human beings a direct sense of the scale of the Solar System and, in fact, Venus transits have historically been used precisely to measure the distance scale of the Solar System.

The Department of Physics & Astronomy, the Centre for Planetary Science and Exploration (CPSX), and the Royal Astronomical Society of Canada (RASC) are working together to offer the public the best and safest observing experience. From about 5:30 p.m. onward, we will open up the Cronyn Observatoryand use the main telescope to project images of the Sun on a screen. In addition, we will have an observation station in the southeast corner of the Springett Parking Lotwhere we will offer diverse views of the event, including through a state-of-the-art solar telescope. At both sites, we will be distributing eclipse glasses that allow you to see the transit with your own eyes. A “planet walk” between the two sites will show a scale model of the Solar System, and in the conference room of the Cronyn Observatory, we will present a small exhibit about Venus and transits, as well as a live feed of the event as seen from different locations worldwide. Many professional astronomers will be around to answer any question you may have. After sunset, we will keep the observatory open for stargazing, which will include telescopic views of Mars, Saturn, and many more wonders of the Universe. In case of bad weather, the exhibit at the observatory will be open, and astronomers will give presentations about related topics.

It would be my pleasure and my honour to greet you and your family at this event, and share this unique and historical moment. Please do not hesitate to contact me for further information.

Sincerely,

Jan Cami

Cronyn Coordinator

Jan Cami                                                              e-mail : jcami@uwo.ca

Assistant Professor                                         Tel : +1 519 661 2111 ext. 80978

University of Western Ontario                   Fax : +1 519 661 2033

Department of Physics and Astronomy

Room 203 P&AB

London, Ontario N6A 3K7

CANADA

Venus Transit poster.pdf Download this file

Poster: http://www.physics.uwo.ca/colloquia/Colloquia%20Notices/2011_2012/HUTTER%20Colloquium.pdf

Western University
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:           Thursday, 31^st May 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Jeff Hutter
Department of Physics & Astronomy
Western University

“Examining the role of crystallization inhibitors using atomic-force microscopy”

ABSTRACT

Kinetic inhibitors are additives that affect crystallization kinetics without altering thermodynamic properties, such as the melting point. Based on their effectiveness at exceedingly small concentrations, models for the mechanism by which such additives operate have assumed adsorption to crystal growth faces. A well-known model proposed in 1958 by Cabrera and Vermilyea (the C-V model) suggests that impurities adsorb to growth faces and pin growth steps, forcing them to curve, and thus decreasing the effective supersaturation via the Gibbs-Thomson effect. Despite considerable effort, direct evidence for this mechanism has only been offered for a few systems, while significant objections have been raised: How can the irreversible adsorption required to pin growth steps be reconciled with the observed dependence on inhibitor concentration? How can growth proceed at all in the presence of strongly adsorbed inhibitor molecules?

The main example of kinetic inhibition that will be discussed here involves the crystallization of calcium oxalate monohydrate (COM), which is the main mineral component of kidney stones. Certain proteins, such as osteopontin (OPN), are known to inhibit stone formation, but the details of the process are not well understood. In order to determine the role of such inhibitors, we have examined the growth of COM at the molecular level and in real time using the atomic force microscope (AFM). We find that the presence of OPN, as well as synthesized peptides corresponding to portions of the OPN molecule, results in clear changes in the morphology and propagation speed of growth steps. By observing the subsequent recovery of COM growth when the inhibitor is flushed from solution, we can test the validity of the assumptions of the C-V model. An improved understanding of this inhibitor mechanism may result in the design of therapeutic agents for the prevention of kidney stones, as well as an improved ability to tailor additives for a variety of commercial processes.

Poster: http://www.physics.uwo.ca/colloquia/Colloquia%20Notices/2011_2012/MATNEY%20Joint%20Colloquium.pdf

JOINT SEMINAR—the Department of Physics and Astronomy and theCentre for Planetary Science and Exploration (CPSX)

Date:          MONDAY, 28^th May 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Mark Matney
Orbital Debris Program Office
NASA Johnson Space Center

“The Challenge of Orbital Debris”

ABSTRACT

Since the dawn of the Space Age more than 50 years ago, humans have been launching objects into the space environment faster than they have been removed by active means or natural decay. This has led to a proliferation of debris—derelict satellites, discarded rocket upper stages, and pieces from satellite breakups—in Earth orbit, especially in well-used orbital regimes. This talk will summarize the current knowledge of the debris environment and describe plans to address the challenges orbital debris raises for the future usability of near-Earth space. The talk will be structured around 4 categories: Measurements, Modeling, Shielding, and Mitigation. This will include discussions of the long-term prognosis of debris growth (i.e., the “Kessler Syndrome”) as well as plans for active debris removal.

TODAY

The University of Western Ontario
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:           Monday, 30^th April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Jean-Michel Désert
Harvard College Observatory
Harvard-Smithsonian Center for Astrophysics (CfA)

“From statistics to individual characterization of exoplanets”

ABSTRACT

The field of exoplanetary science has changed gear from the investigation of individual objects to statistical studies. In this talk, I discuss both the statistical approach and individual atmospheric characterization.

The Kepler mission has revealed an extraordinary and unprecedented number of small exoplanet candidates. However, a fundamental question remains about the overwhelmingly large sample of Kepler candidates: are these objects bona-fide planets? Importantly, we would like to know the false positive rate of this sample. I present a large program, obtained with the Spitzer Space Telescope, whose goals are to validate the planetary status of candidates and to estimate the Kepler false positive rate. Our results suggest that the Kepler false positive rate in this subset of candidates is low.

Answers to key questions about exoplanet science come not only from statistics, but also from individual characterization. Observations of their atmospheres are the only effective way at present to address the composition of exoplanets quantitatively and, by necessity, remotely. I present an ongoing comparative exoplanetology program to characterize planetary systems transiting nearby stars through the observation of their atmospheres. This project provides a powerful insight into the formation and evolution of planetary systems in general and enhances our understanding of our own solar system’s formation, one of the central questions in astrophysics. I also discuss the prospect of probing rocky exoplanet atmospheres orbiting in the habitable zone of their parent stars with future facilities.

TODAY

Western University
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:          Thursday, 26^th April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Shelley Wright
Department of Astronomy & Astrophysics
and Dunlap Institute of Astronomy & Astrophysics
University of Toronto

“Studying Galaxies in the Early Universe with Innovative Astronomical Instrumentation”

ABSTRACT

Studies of galaxies in the early universe (z > 1) have greatly benefited from recent advances in diffraction-limited techniques on 8-10m telescopes using adaptive optics (AO) and integral field spectroscopy. These innovative spectrographs have led to significant scientific achievements and are stimulating the design of future instrumentation. My talk will focus on development and use of the latest near-infrared instruments behind Keck Observatory’s AO system. I will present OSIRIS and Keck AO observations of spatially resolved optical emission lines (e.g., Halpha, and [N II]) from high-redshift (1 < z < 3) star forming galaxies. These results are part of an ongoing survey to study the dynamics, chemical abundances, and active galactic nuclei (AGN) in early galaxies. The high spatial resolution and 2D capability of an integral field spectrograph has allowed the discovery of some of the lowest luminosity AGN known at this epoch, and I will discuss their potential impact on high-redshift metallicity studies and galaxy formation. Lastly, I will discuss future instrumentation upgrades for OSIRIS and development of new instrumentation on extremely large telescopes (30m), which will offer extraordinary potential to probe the dynamics, assembly, and abundances of galaxies in the early universe.

  PHYSICS & ASTRONOMY Department

— Special Undergraduate LevelTalk —

Date:          Tuesday, 1^st May 2012
Time:          10:30 a.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Jean-Michel Désert
Harvard College Observatory
Harvard-Smithsonian Center for Astrophysics (CfA)

“Searching for signatures of life in the atmospheres of habitable exoplanets”

ABSTRACT

Biosignatures are the signs of life in the atmosphere of an exoplanet. On the Earth, the main biosignatures are oxygen, which is produced only in large quantities by plants and photosynthetic bacteria, and ozone, which is produced photochemically in the atmosphere from oxygen. Transiting extrasolar planets currently offer the best configuration in which to investigate their atmospheres and to search for remote signatures of life on these worlds. I will present the outstanding challenges, both technically and observationally, that we will need to overcome in order to probe rocky exoplanet atmospheres orbiting in the habitable zone of their parent stars, with the ultimate goal of detecting the planets’ biosignatures.

Poster: http://www.physics.uwo.ca/colloquia/Colloquia%20Notices/2011_2012/DESERT%20Research%20Talk.pdf

The University of Western Ontario
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:           Monday, 30^th April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Jean-Michel Désert
Harvard College Observatory
Harvard-Smithsonian Center for Astrophysics (CfA)

“From statistics to individual characterization of exoplanets”

ABSTRACT

The field of exoplanetary science has changed gear from the investigation of individual objects to statistical studies. In this talk, I discuss both the statistical approach and individual atmospheric characterization.

The Kepler mission has revealed an extraordinary and unprecedented number of small exoplanet candidates. However, a fundamental question remains about the overwhelmingly large sample of Kepler candidates: are these objects bona-fide planets? Importantly, we would like to know the false positive rate of this sample. I present a large program, obtained with the Spitzer Space Telescope, whose goals are to validate the planetary status of candidates and to estimate the Kepler false positive rate. Our results suggest that the Kepler false positive rate in this subset of candidates is low.

Answers to key questions about exoplanet science come not only from statistics, but also from individual characterization. Observations of their atmospheres are the only effective way at present to address the composition of exoplanets quantitatively and, by necessity, remotely. I present an ongoing comparative exoplanetology program to characterize planetary systems transiting nearby stars through the observation of their atmospheres. This project provides a powerful insight into the formation and evolution of planetary systems in general and enhances our understanding of our own solar system’s formation, one of the central questions in astrophysics. I also discuss the prospect of probing rocky exoplanet atmospheres orbiting in the habitable zone of their parent stars with future facilities.

TODAY @ 1:30

The University of Western Ontario
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:          Monday, 23^rd April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. Stanimir Metchev
Department of Physics and Astronomy

Stony Brook University, New York

“Exoplanetary Worlds: Atmospheres, Architectures, and Evolution”

ABSTRACT

The detection of global weather phenomena in irradiated extrasolar hot Jupiter planets has provided tremendous insights into their atmospheric structure. Non-irradiated substellar atmospheres probe weather in an entirely different regime, where global atmospheric flows result primarily from a combination of rapid rotation and internal convection—e.g., as in the atmosphere of Jupiter—rather than from external forcing. Isolated brown dwarfs are ideal targets for such investigations because they possess planet-like atmospheric dynamics, yet have greater intrinsic brightnesses and lack nearby bright stars to contaminate observations. I will overview recent results on non-irradiated brown dwarf and planetary atmospheres, and will present the prospects for the direct characterization of extrasolar planets with the coming generation of extreme-contrast imaging telescopes.

TODAY – @ 1:30 and 4 p.m.

TWO talks by Dr. John Berlinsky:

Poster:  http://www.physics.uwo.ca/colloquia/Colloquia%20Notices/2011_2012/BERLINSKY%20Colloquium.pdf

Western University
DEPARTMENT OF PHYSICS AND ASTRONOMY

PHYSICS & ASTRONOMY COLLOQUIUM

Date:          Thursday, 19^th April 2012
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

Dr. John Berlinsky
Perimeter Institute for Theoretical Physics

“Quantum Oscillations in High Temperature Superconductors”

ABSTRACT

High temperature superconductivity occupies one region of the phase diagram of the rare earth cuprates, which also includes regions of antiferromagnetism at low doping and pseudogap, stripe, and strange metal behaviour for intermediate doping, as well as a normal Fermi liquid at high doping. These are clearly strongly correlated systems and, since the beginning, much of this strange behaviour has been interpreted in terms of Mott-Hubbard physics. And so the discovery of quantum oscillations, which are usually a clear signature of normal Fermi liquid-like behaviour, came as something of a surprise which deepened the mystery of high T_c, rather than clarifying it. Furthermore it was difficult to understand the observed frequencies of the quantum oscillations without invoking some kind of translational symmetry breaking and superlattice model. In this talk we will describe the general situation of the phase diagram and the observations of quantum oscillations and then present some recent results for a simple model of quantum oscillations arising from superconducting stripes.

Coffee & cookies will be available, courtesy of PASA.

In addition, Dr. Berlinsky will make a second presentation later in the day:

Date:          Thursday, 19^th April 2012
Time:          4:00 p.m.
Location:    Physics & Astronomy Classroom 117

Dr. John Berlinsky
Perimeter Institute for Theoretical Physics

“Perimeter Scholars International (PSI) Information Session”

Perimeter Scholars International is a one-year Masters level course in Theoretical Physics designed to bring highly qualified, highly motivated graduate students to the cutting edge of theoretical physics in an intense, interactive learning environment.

http://www.perimeterscholars.org/