Dedication

Optical Powers is dedicated to the memory of Walter J. Wild, Senior Research Associate, The University of Chicago.  Walter contributed to mathematical models of Adaptive Optics (AO) and conducted AO experiments at The University of Chicago Yerkes Observatory.

Optical Powers
Introduction for Teachers

Amazing images and volumes of astronomy information fill the news and Internet everyday from large telescopes here on earth, or space-based telescopes and spacecraft speeding their way through our solar system in search of spectacular close-ups.  Our scientific understanding of the universe we live in is expanding and so is the public's fascination with astronomy.  Astronomical images spark our imaginations and ignite our excitement with new discoveries. With the increasing affordability of telescopes equipped with high quality CCD cameras, the opportunities for anyone with the interest to make significant contributions to science are exploding.  The personal satisfaction alone of successfully targeting and capturing an image of one's choosing, perhaps one too dim to been seen with the unaided eye, fuels many amateurs to push the limits of their equipment. 

Many astronomy curricula tap young people's natural curiosity about the universe. Generating interest in astronomical images is not a problem.  The challenge is providing an approach that engages students in scientific thinking and analysis of images that leads to an understanding of the technology of telescopes, optical systems, and imaging cameras.  Our effort has been to find a way for teachers with only minimal experience in this area to guide their students efficiently through the maze of variables that go into producing useful images while maintaining a foundation in understanding the science involved. 

Goals of Optical Powers Workshops and Curriculum:

• To enhance teacher and student understanding of the process of science and technological design of scientific instrumentation, within the context of astronomy.
• To provide students with a rich experience of telescopes and astronomical imaging, scientific inquiry, experimental methods, the process of science, mathematical analysis of quantitative data, and the interplay of components in systems design.
• To engage students in active lab activities that are hands-on and computer-based, using image processing software.
• To emphasize the light-collecting, magnifying, and resolving powers of astronomical telescopes.
• To create a structure for a professional development workshop for teachers of middle, high school, or junior college students.

It is expected that teachers attending workshops for Optical Powers, who are also involved in the Hands-On Universe project or other educational telescope projects, will be able to plan and complete more efficiently observing sessions for themselves and their students. Teachers and their students will be able to choose and manipulate telescope/imaging systems to match the goals of observing projects. Conversely, they will be able to design an astronomy project to match the characteristics of available telescope and imaging systems. It is also expected that as a result of engaging in these activities participants will appreciate the engineering and design involved in telescope and imaging systems of major NSF and NASA astronomy projects and missions, as well as the science cases which drive such missions.

Optical Powers Experiments

The Optical Powers experiments are simple in design and could be replicated by an amateur astronomer for visual observations or CCD imaging.  So, a teacher, who is also an amateur astronomer, or a teacher who has joined Project ASTRO or invited a local astronomy club to support her by helping with a school-centered Star Party, can use this module to guide practical experiments that demonstrate basic principles of telescopes and CCD  imaging systems.

Through the activities and experiments presented, Optical Powers focuses on:

• leading students through a series of investigations that explore the scientific principles that create the images produced by telescopes.
• presenting the telescope/CCD as a system with components that can be manipulated to produce images that suit the needs of the observer and the characteristics of the objects being imaged.

Assessment/Evaluation

Assessment in Optical Powers is an ongoing process. The unit begins with An Introduction to Telescopes, which is designed to assess the prior knowledge of your students as you begin. Each of the remaining activities concludes with suggestions for assessing student progress. Because activities go together to build a total understanding of telescope/CCD systems and the resulting images, we recommend that students keep a portfolio of their work. Students should choose and include assignments, journal entries and images that illustrate the key ideas and help them recall what they have learned.   Class, group or individual construction of a concept map which relates the optical systems, CCD camera attributes, and imaging variables to the qualities of resulting images will help students explain and refine their ideas about how all of  the variables involved affect images.

The Activities Included in Optical Powers

Students observe and analyze data collected from telescope and imaging experiments.  Students investigate the brightness, image size or magnification and angular size of targets, pixel scale and field of view, and resolution of detail in images. The variation of results is related to the properties of the astronomical target and the manipulation of telescope variables such as aperture, focal length, exposure times, and the imaging camera's chip and pixel size. Students are introduced to the need for adaptive optics systems in Earth-based astronomy, as they consider the limits of resolution in traditional telescope systems and compare images taken with adaptive optics systems off and on.

While all the activities in the Optical Powers unit are designed to directly engage students in exploring the topic, there are two primary formats, investigations and experiments.  Whenever possible, we have tried to create imaging experiments. Experiments allow students to uncover the effect of changing various components of the telescope/CCD system one variable at a time. In any case, the students are analyzing images which were collected in investigations and experiments conducted by teachers using telescopes. Students may conduct similar experiments directly while using different telescopes at a Star Party or when requesting images or remotely controlling telescopes in various educational observing networks and projects.

Each investigation allows students to consider and formulate their own ideas about the problem in question, to use astronomical images to gather useful data, analyze the data they gather and form conclusions about the role of each variable in the astronomical imaging.  Depending on the amount of direction students need, help them progress from teacher directed to more independent work in the following steps.

1. Guide your students in selecting the type of data to collect and the tools to use.  Student pages have tables for data collection and analysis. When computer lab time is an issue, you may choose to divide data collection tasks among different groups.
2. Based on the purpose of the investigation, let students decide which data would be useful to gather. Allow students to create their own systems for recording data. 
3. Brainstorm as a group which factors to investigate and how to present the information.
4. Allow teams to gather whatever data they decide upon.  Save sharing of approaches for the discussion of conclusions.
5. Give students some time to look at the image sets and begin gathering data before sharing options.  Then allow groups additional time to finish the task after brief discussion.

Note:  Spreadsheets can be valuable tools and can assist students in conducting more advanced analysis of the data. They can easily and clearly handle class data that can then be averaged for collaboration.  A few sample spreadsheets have been provided in the event that you need help getting started. If your students have experience with using spreadsheets already, they can design their own to match the data they collect.  But beware that students are not just filling in numbers without understanding the formulas present in the spreadsheets.

Optical Powers Project Team

Optical Powers was written by a team of teachers working with Vivian Hoette at The University of Chicago Yerkes Observatory in Williams Bay, Wisconsin; and Professors Doug Arion and Kevin Crosby and undergraduates at Carthage College in Kenosha, Wisconsin. The F-Box was designed and constructed by the Carthage College team. 

Participants involved in creating  ideas, writing lessons, and imaging at the telescopes include teachers: Jacqueline Barge, Barbara Bergmann, Sharon Carr, Kenneth Gardner, Art Griffin, James Hanna, Gail Hermann, Lori Lendio, Kevin McCarron, Frank Mills, Dennis Moore, Kim Warman, Cathy Wentworth, Sharon White, Ralph Zebell, Lynne Zielinski, Marilyn Zimny, Kaoru KIMURA of the Riken Institute in Japan, and Carthage College undergraduate Orson Bengert.  During the summer of 2000, Ken Gardner formalized the hands-on activities into a set of learning cycle style classroom lab documents. 

Kate Meredith and Vivian Hoette compiled, formatted, and edited everyone's work to create Optical Powers (August 2002).  A final review team included teachers Michael Clark, Ruth A. Czarnecki, Kenneth Gardner, James Hanna, Carol Katzberger, Rich Lohman, Kevin McCarron, Frank Mills, Pious Okoro, Vasaliki Valkanas, Sharon White, Lynne Zielinski, and Tim Barclay of TERC and Hands-On Universe. Kaoru KIMURA translated this work to Japanese for the JaHOU teachers.

Many suggestions have been incorporated into this version of Optical Powers.  However, we are continuing to add to and edit these activities for content and style.

Assistance from Experts

Education Retreats hosted by the Center for Adaptive Optics inspired the necessity for developing curriculum regarding the basics of telescope and imaging systems as a foundation for further education in the techniques and strategies of adaptive optics. Many astronomers from the Center for Adaptive Optics, The University of Chicago in particular, advised and assisted the Optical Powers team; their patience and the clarity of their explanations were greatly appreciated.  We especially wish to thank Professors Rich Kron, Al Harper, Ed Kibblewhite, and Kyle Cudworth, Director of The University of Chicago Yerkes Observatory.  We also wish to thank Associate Professor Richard Gelderman of Western Kentucky University, and Bernhard Beck-Winchatz, Associate Director of the Space Science Center for Education and Outreach at DePaul University. Please also see the Optical Powers webpage listing participating teachers, undergrads, faculty and astronomers.

Telescopes and Imaging

Most of the telescope and imaging experiments occurred at The University of Chicago Yerkes Observatory and were conducted by teachers and undergraduates.  Access to the 24 inch telescope at Yerkes Observatory and the Yerkes Rooftop Remote telescope systems (enclosure built by Kevin McCarron, remote software by Jerry Gunn) were essential resources.   Telescopes and imaging cameras purchased by the Illinois State Board of Education through the Near and Far Sciences for Illinois professional leadership program were also essential to the imaging experiments conducted for these activities.  These experiments are models which might be replicated using a school's, teacher's, or amateur astronomer's telescopes and imaging systems.

Image Processing Software and Images

Hands-On Universe (HOU) Image Processing software and analysis techniques are used throughout this module.  One can obtain this software through the HOU website: http://hou.lbl.gov or the Lawrence Hall of Science, University of California, Berkeley.  An image archive is maintained by HOU.  Many more images can be downloaded from the HOU website.  Hands-On Universe is a National Science Foundation project.

Funding and Publication

Optical Powers was funded by the National Science Foundation Science and Technology Center for Adaptive Optics, University of California, Santa Cruz, and is published on the web by Hands-On Universe through Lawrence Hall of Science, University of California, Berkeley.