Physics and Astronomy Colloquium Series
Winter 2011

Date

Talk

Tuesday
4 January

Exploring the Standard Model at the Large Hadron Collider

Jason Slaunwhite
CERN

The Large Hardron Collider (LHC) is one of the world's largest scientific experiments. It aspires to answer some of the most exciting questions in particle physics today. In this talk, I will discuss the current model of particle physics and describe some of the outstanding questions. I will explain how we use the LHC answer these questions and highlight some recent results.

Thursday
13 January

available

Thursday
20 January

Talking to My Dog About Science: Why Public Communication Matters, and How Social Media Can Help.

Chad Orzel
Union College

At a time when the primary challenges facing the world are scientific in nature-- pandemic disease, global climate change, green energy and technology-- it is more important than ever that the general public have some understanding of and appreciation for science. At the same time, polls show that public understanding of science lags far behind the necessary level, and well-funded media operations attempting to sow doubt about issues like climate change have had a major negative impact. In this talk, I will discuss some of the problems with communicating science to the general public, and discuss the new opportunities for public communication afforded by Internet technologies.

Thursday
27 January

available

Thursday
3 February

The Glass Transition Temperature: Relationship between Thin Films, Nanoporous Materials, and Nanocomposites

Rahmi Ozisik
Department of Materials Science and Engineering, and Rensselaer Nanotechnology Center, RPI

Studies by various researchers showed unequivocally that the glass transition temperature (T_g) of polymer thin films depends on the thickness of the film when the thickness decreases below 100-150 nm. In the case of free-standing thin films, it was shown that T_g always decreases; however, in the case of thin films sandwiched between substrates, T_g might increase, decrease, or not change at all. This behavior was attributed to the interaction of the polymer with the substrate such that if the interface is wetting, T_g increases; if the interface is non-wetting, T_g decreases; and if the interface is neutral, then the T_g does not change.

Recently, it was shown that T_g also changes in nanoporous materials and nanocomposites as a function of pore volume ratio or nanofiller concentration. In the current talk, I will present results obtained from our own studies on nanoporous polyetherimide (PEI), and silica/poly(methyl methacrylate) nanocomposite systems. A correlation between thin film thickness and pore volume ratio or nanofiller concentration will be established. In addition, the effects of confinement (due to thickness or distances between nanopores/nanofillers) and interface (polymer-substrate, polymer-nanofiller) on T_g will be presented.

Thursday
10 February

The Roles of High and Low Energy Electrons in Nanofabrication

Jason Sanabia
Raith USA, Inc

In his 1959 speech entitled There's Plenty of Room at the Bottom, Richard Feynman asked "Why cannot we write the entire 24 volumes the Encyclopedia Brittanica on the head of a pin?" After explaining how it was possible, Richard Feynman next asked "How do we write it?" and then hypothesized "We can reverse the lenses of the electron microscope." Toward the end of his speech, Richard Feynman offered a price of $1,000 to "the first guy who can take the information on the page of a book, and put it on an area 1/25,000 smaller in linear scale, in such manner that it can be read by an electron microscope." In 1985, Richard Feynman mailed a check for $1000 to Tom Newman, then a graduate student in R. Fabian W. Pease's group at Stanford University, who used electron beam lithography to write the opening page of Dickens' A Tale of Two Cities at a scale of nanometers.

Today, 50 years since Richard Feynman launched the field of nanotechnology, electron beam lithography is a critical facility for the world's research in nanotechnology. Device physics research (graphene and spintronics), materials science (bit patterned media), electrical engineering (transistors), mechanical engineering (nanoelectromechanical systems, NEMS), optical engineering (waveguides and photonic structures), and biophysics (single molecule detection) are examples of today's active fields of research that benefit from electron beam lithography facilities. But why cannot electron beam lithography do everything? Why is it difficult to control matter below 10 nm with electron beam lithography? What prevents the manufacture of computer chips with electron beam lithography? I will introduce the basic concepts of electron beam lithography, with particular emphasis on the roles of the high and low energy electrons. Within this framework, I will discuss the today's physical science challenges that limit to the application of electron beam lithography.


Figure 1: Left: The opening page of Dickens' A Tale of Two Cities written within a 6 mm square at 25nm linewidth using electron beam lithography circa 1985. Courtesy of R. Fabian W. Pease, Stanford University. Right: A nanoelectromechanical actuator realized by electron beam lithography whereby a multi-walled carbon nanotube supports a metal plate rotor. Courtesy of John Cumings, University of Maryland.

Thursday
17 February

ALFALFA and the Hunt for Extreme-Mass Galaxies

Ann Martin
Cornell University

The ongoing Arecibo Legacy Fast ALFA (ALFALFA) survey is using the Arecibo Observatory to make a census of neutral hydrogen gas in ~ 30,000 nearby galaxies. This method is efficient at finding very low mass, very faint galaxies as well as distant, rare high-mass galaxies. The statistical distributions of gas-rich galaxies in the local Universe will reveal relationships between galaxies' stellar properties, star formation histories, gas masses, and environment, helping us to untangle galaxy evolution. I will describe ongoing projects that challenge our current understanding of both very small and very large galaxies. I will discuss two statistics, the neutral hydrogen mass function and the correlation function, and how they reflect the cosmological implications of the characteristics of the ALFALFA sample.

Thursday
24 February

FOUNDERS DAY

Thursday
3 March

available

Thursday
10 March

available

Schedule for Spring Term 2011