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Physics & Astronomy Seminar
Spring 2000

Seminars are held on Tuesdays, 3:45-4:45pm in Science Building #101, unless otherwise noted.
Meet at 3:30 in Science Building #153 for refreshments.
See Calvin's Visitor Resources for maps and directions.
If you would like to receive regular email announcements for each week's seminar, or have other questions or comments, contact seminar chair Deborah Haarsma.

Previous semesters: Fall 1999
Next semester: Fall 2000

Date	Title (click on title for abstract)	Speaker
February 1	Spring Semester Kick-Off Party!
February 8	Discussion of "A Planet Beyond Pluto"
February 17, THURSDAY	Constructing Artificial Atoms of Matter and Antimatter (and Other Games that Make God Happy)	Gerald Gabrielse, Professor of Physics, Harvard University
February 22	Viewing and discussion of a PBS Documentary: "Transistorized!"
February 29	Can We Teach Scientific Thinking Skills? A Case Study at Calvin College with Elementary Education Students	Jim Jadrich, Calvin College
March 7, during Reading/Advising Recess	Thin Film Solar Cells - Benefits and Challenges	Kent Price, University of Toledo
March 14	Measuring particle trajectories in turbulence: how detectors from an e+e- collider have opened a new window on turbulent mixing	Greg Voth, Cornell University
March 16, THURSDAY at 4:00pm	Soap Bubbles on a Microscopic Scale - Sheets to Cylinders: The lamellar to hexagonal phase transition in lipid-water systems.	Paul Harper, Grand Canyon University
March 21	Spring Break
March 28	Refreshments as usual, but no seminar. Come hear what everyone did over Spring Break.
April 4	Cosmological Parameters from Gravitational Lenses	Debbie Haarsma, Calvin College
April 18	Physics Phun: Preview of "Western Michigan Spring Science Festival" Demonstrations	Steve Steenwyk and Dave VanBaak, Calvin College
April 25	Steady-State Cosmology as an Example of Fringe Science	Loren Haarsma and Debbie Haarsma, Calvin College
May 2	Spring Research Project on Trapped Krypton	Nathan Miller, Calvin junior
May 9	Viewing and discussion of Cosmic Voyage

February 8:
The BBC Online Network called it A Planet Beyond Pluto. The more modest title of the journal article by J. J. Matese is "Cometary Evidence of a Massive Body in the Outer Oort Cloud" (you can download the article at Matese's web site). Prof. Larry Molnar is a local expert on this topic (he has access to the cometary data base, and was at the conference where the work was presented). He will lead us in a discussion of the science behind this news story from October 1999. We will also discuss the media's coverage of science, including examples of good and poor science journalism.

THURSDAY, February 17:
Dr. Gerald Gabrielse, Professor of Physics, Harvard University
Constructing Artificial Atoms of Matter and Antimatter (and Other Games that Make God Happy)
Professor Gabrielse is a graduate of Calvin College. He currently serves on the Calvin College Board of Trustees and chairs its education committee. He has been Professor of Physics at Harvard since 1987 and becomes the chair of the department in a few months. (One of his proud accomplishments at Harvard was supervising the thesis work of Professor Loren Haarsma.) He led the international TRAP team which developed and demonstrated the techniques for confining cold antiprotons -- the antimatter counterpart of protons. He currently leads the international ATRAP team which is seeking to form and study cold antihydrogen atoms for the first time, in a facility specially constructed in Geneva, Switzerland for this purpose.
Professor Gabrielse will discuss experiments done by his research group in which antiparticles, particles, magnets and batteries are used to form artificial atoms. His goal is to give an interesting overview without huge amounts of technical details. He promises that his lecture and pictures will be understandable to first year students and faculty alike. The technically astute who wish to delve deeper than is required for the colloquium might want to look at the five Physical Review Letters and Physics Letters papers published in 1999. These are available on his web page.

February 22:
Viewing and discussion of a PBS Documentary: "Transistorized!"
"The transistor is one of the 20th century's most important inventions. It revolutionized technology and launched the information Age. Its creation is a dramatic story of top secret research, serendipitous accidents, collaborative genius, and clashing egos. "Transistorized!" tells the compelling story of the history of the transistor and the scientists who discovered it. They include William Shockley, who assembled the team at Bell Labs that built the first working transistors, but whose driving ego ultimately ended their collaboration; John Bardeen, a theoretical genius whose profound insights paved the way to the final discovery; and Walter Brattain, whose persistent tinkering led to the breakthrough that results in the first transistor."

February 29:
Can We Teach Scientific Thinking Skills? A Case Study at Calvin College with Elementary Education Students
Prof. Jim Jadrich, Calvin College

March 7 (during Reading/Advising Recess):
Kent Price, University of Toledo
Thin Film Solar Cells - Benefits and Challenges
Photovoltaics, the direct conversion of light into electricity, has the potential to provide pollution-free, low-cost electricity. The first of these objectives has already been achieved with conventional solar cells made from bulk materials. However, such materials are too expensive for most large-scale applications. Thin-film solar cells can be fabricated much more cheaply than conventional solar cells, but do not match the performance of the more expensive devices. This talk will describe basic photovoltaic device operation, discuss the benefits and challenges of thin-film photovoltaics, and present some of the work being done at the University of Toledo to enhance the feasibility of thin film solar cells.

March 14:
Greg Voth, Cornell University
Measuring particle trajectories in turbulence: how detectors from an e+e- collider have opened a new window on turbulent mixing
Turbulent mixing is important both to practical environmental and technological problems and to fundamental theories of turbulence. A natural way to study mixing is to analyze the motion of individual fluid particles, but obtaining high resolution particle trajectories in intense turbulence is a difficult experimental challenge. We have implemented a particle tracking system using silicon strip detectors which were designed for vertex detectors in high energy physics colliders. This system can measure the full 3 dimensional trajectories of tracer particles at 70,000 frames per second with 512 strip spatial resolution. Measurements of particle accelerations allow a new perspective on questions about universality of the small scales in turbulence and on attempts to model turbulent mixing.

THURSDAY March 16, at 4:00pm :
Paul Harper, Grand Canyon University
Soap Bubbles on a Microscopic Scale - Sheets to Cylinders: The lamellar to hexagonal phase transition in lipid-water systems.
Soap bubbles have a universal appeal, intriguing both young children and adult physicists and mathematicians. Most people have enjoyed viewing the many macroscopic structures formed by soap; on a microscopic scale, there is even more variety and beauty. The talk will deal with some of the basic physics of soap, the biological relevance of soap, how physics drives the structures that are seen, and the results of an experiment involving several different types of soap.

March 21: Spring Break

March 28: Refreshments as usual, but no seminar. Come hear what everyone did over Spring Break.

April 4:
Prof. Debbie Haarsma, Calvin College
Cosmological Parameters from Gravitational Lenses
Gravitational lenses are one of the most beautiful confirmations of the theory of general relativity. In addition, they provide useful tools for addressing many cosmological questions. I will give an overview of the cosmological applications of gravitational lensing, then discuss in detail the use of lensed time delays to determine cosmological distances. The distance to one lens determines the Hubble parameter H_0, and the distances to several lenses at a range of redshifts could set important limits on the matter density of the universe Omega_m and the cosmological constant Omega_Lambda. These three cosmological parameters can be used to calculate the current age of the universe and to predict whether the universe will expand forever or ultimately collapse on itself.

April 18:
Professors Steve Steenwyk and Dave VanBaak, Calvin College
Physics Phun: Preview of "Western Michigan Spring Science Festival" Demonstrations
On the evening of April 18, Profs. Steenwyk and Van Baak will present physics demonstrations to middle school students and their parents as part of the Western Michigan Spring Science Festival. For seminar that afternoon, we will get a preview of these demonstrations. Prof. Van Baak will demonstrate the properties of light and color, and show why "to see is to understand". Prof. Steenwyk will present several surprising manifestations of magnetism. Come enjoy the show!

April 25:
Professors Loren Haarsma and Debbie Haarsma, Calvin College
Steady-State Cosmology as an Example of Fringe Science
Abstract: "Big Bang" cosmology is widely regarded as a highly successful theory of the universe, a theory supported by convincing data. A handful of cosmologists, however, still prefer "Steady State" cosmology, in which the history of the universe stretches infinitely far back in time. Geoffrey Burbidge, Fred Hoyle, and Jayant Narlikar, three well-respected cosmologists, recently explained and defended steady-state cosmology in _Physics_Today_ (April 1999, "A Different Approach to Cosmology"; copies are available). We will discuss the scientific issues raised in this article. We will also use the article as a case study in "fringe science." Why do some scientists stick to a model which has been rejected by a large majority of workers in the field? What pitfalls can scientists fall into in this situation? When does properly-done "fringe science" become improperly-done "folk science" -- scientific-appearing activities done merely to reinforce a philosophical position? What similarities and differences are there between these steady-state cosmologists and the Young Earth Creationist movement?

May 2:
Nathan Miller, Calvin junior
Spring Research Project on Trapped Krypton
MOTs, or Magneto Optical Traps, provide a way to contain atoms in a small area for a very long time. This paves the way for new experiments that would otherwise be impossible. This semester, for the first time at Calvin, we have obtained such a trap in Krypton. We are now beginning to use it in the study of the long lifetimes of particular Krypton energy states.

May 9:
Viewing and discussion of Cosmic Voyage
The department recently acquired this 35 minute film, which was originally made in IMAX format (since there isn't a 3-story IMAX theater on campus, we'll be viewing it on the 21" departmental TV). Many of you have seen the old science film "Powers of Ten". Cosmic Voyage is a new presentation of powers of ten, zooming across 42 orders of magnitude from a quark to the observable universe. The film also zooms across time from the Big Bang to the rise of humans on Earth. The images of galaxy formation and a galaxy collision are based directly on research-quality numerical simulations.

Web page maintained by dhaarsma@calvin.edu. Last updated May 1, 2000