About This Vignette

This is meant to present a picture of some of the possibilities available when using simulations from MASTER, tools from HOU, and collaboration in the classroom. It is not intended to show the only way they can be incorporated, nor should it be construed to indicate dependencies. In short, it is a description of what can be done, not a directive stating what must be done.

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Galaxies and Science

Ms. H sees that the science curriculum this year includes a chapter on galaxies. She has learned that many aspects of galaxy formation--why some galaxies are spiral in shape, while others are elliptical and still others are irregular--are not yet understood by scientists, and she plans to use this fact to capture the students' interest and imagination.

Ms. H knows one of the most important tools in the attack on this problem is modeling galaxy formation on supercomputers. She wants to help her students get a feel for what these scientists are doing in order to enable them to see science as a process of inquiry, and to provide a natural way of incorporating simple research projects involving the development and use of models.

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An Astronomical Mystery

The chapter previous to the one on galaxies covers the solar system. In order to set the stage for the section on galaxies, Ms. H used some of the solar system related activities to stimulate questions in the students' minds about mysteries of the observable universe. During a night field trip with a local astronomy club, she arranged for the students to view not only the planets, but several other objects as well--things such as nebulas, clusters, and galaxies which appear only as fuzzy blobs of light to the naked eye or in a small telescope. She focused particular attention on the andromeda galaxy, dubbing it the "Astronomical Mystery Object," and asked them to think about what it might be.

In class the next day, Ms. H asked how they might solve the mystery of the the actual nature of this object. Although some of the students had learned the true identity of the object by looking in books or asking their parents, Ms. H simply capitalized on this as an opportunity to help the students understand that science is more than a set of facts available in books or from those that have read books. She commended the students for seeking further knowledge outside of the classroom, then presented them with a question--how did the book, parent, or other source know what the mystery object was?

The class eventually agreed that the scientists learn these things through observations. Ms. H asked the students if they could make the same observations that the scientists made. Many students suggested requesting an image of the Mystery Object through Hands-On Universe (HOU). The image was requested in plenty of time for use by the day of the first galaxy lesson.

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Researching and Publishing

When it came time to begin the galaxy unit, Ms. H presented the HOU image of the Mystery Object. She told them that they were to pretend that they were the first people ever to see an image of this object through a telescope, and that they were to come up with a press release about the true nature of the object that they had discovered.

In order to add a touch of realism to the activity, Ms. H suggested that the "press release" be "published" on a classroom collaboration discussion list, where students from other classes could respond to it.

The students split into groups, with each group given a copy of the image. Using the image processing tools of HOU and the guidance of Ms. H, the student groups each came up with arguments as to the nature of the mystery object. As the ideas began to develop, Ms. H helped the students realize that they should look for other similar "mystery objects." This would help them understand whether the Mystery Object was a common phenomenon or "one-of-a-kind". She introduced the Messier catalog of "fuzzy objects," and the students requested images of several other Messier objects for comparison.

As the students began to see the various types of galaxies, clusters, and nebulas in the heavens, Ms. H narrowed the focus of their study to galaxies. She discussed with the class the fact that certain features are present in some galaxies, but not others. Once the students began to identify these features for themselves, Ms. H pointed them to the galaxy feature identification activity at the HOU web site. Time was set aside for the students to spend time taking the online quizzes and mastering the vocabulary and identification of features of galaxies.

Finally the press release was finished and uploaded to the classroom collaboration site complete with pictures of the images they collected. Ms. H wrapped up this phase of the project with a discussion of what the students had agreed to put in the press release, and assigned them to write a report individually as a technical follow-up to the press release. In this report they were to give a scientific justification for each claim made in the release.

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Moving to Modeling

Now that the students were familiar with galaxies, Ms. H began implementing the next phase of the project--introducing computational modeling.

Ms. H first pointed out how strong the similarities were between certain galaxy types. She reminded the students that when a scientist notices a pattern, it is a natural step to be curious about it and attempt to investigate it. She asked the students to think about what questions a scientist studying galaxies might have about the patterns that appeared in their observations.

The following list was generated:

Why aren't all galaxies the same?
What causes spiral arms?
What makes some galaxies egg-shaped?

Now Ms. H asked the class how they might find the answers to these questions. She encouraged discussion and listed suggestions. Eventually Ms. H pointed out to the students that one of the most difficult things about answering this question was that there is no way to watch the actual formation of a galaxy. She explained that there are many things in nature that we cannot observe directly. She listed a few examples and asked the students if they could come up with more. They made a list of phenomena, giving in each case the reason that the phenomenon in question was hard or impossible to observe.
Some examples:

Galaxy formation (too slow)
Air and water currents (invisible)
Magma in the earth's mantle (hard to get to)
The center of the galaxy (too far away, too much stuff in the way to see it)
Explosions (too fast, too dangerous to be near)

Ms. H told the students that scientists now use computers to help them understand these hard-to-observe phenomena. They do this through a process called modeling. She explained that scientists use what they have learned from observations to simulate on the computer what they cannot observe. For example, they can use what they know about explosions to simulate one on the computer, where they can watch it in super-slow motion. Similarly, scientists simulate galaxy formation using laws of physics, but they watch it in super-fast forward.

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Using Modeling Technology

Ms. H showed the class a few animations of simulations of galaxy formation she had downloaded from the World Wide Web previously. As they watched the animations, she pointed out how much simulated time was passing in each picture. She asked the students to see if they observed anything in the movies that they had seen in the HOU images. Several phenomena (spiral arms, galactic nucleus) were observable in the animations. Ms. H told them that identifying behavior of a model with the behavior of its real-life counterpart is essential in order to know if the model is valid. Finally, Ms. H told the class that they were going to use a simulation tool similar to the ones that scientists used to understand galaxy formation.

As an introduction to the MASTER software package GalaxSee, Ms. H presented the lesson "Rotation and Flattening", which shows how a large group of gravitationally bound objects will flatten out if a rotation is applied to it. She helped the students understand that this could be a partial explanation of why many of the galaxies they had observed were flat. In the process of presenting the lesson, she explained the options and functionality of GalaxSee so that the students would be familiar with its operation when they started working with it themselves.

Her next step was to present the guided activity "Intruder Galaxy," in which students experiment with the effect that gravitational interaction with another galaxy can have on galactic structure. She emphasized the part of the lesson discussing the careful recording of observations, explaining that success in scientific inquiry is highly dependent on accurate and honest reporting of data.

To demonstrate the role that collaboration plays in science, Ms. H once again used the classroom collaboration site. This time she had the students prepare technical reports of their findings in the "Intruder Galaxy" activity and post them to a discussion on the site. In preparation for this activity, she had corresponded with a computational scientist, Dr. M, who agreed to mentor this project. Dr. M read the reports on the site and posted questions for each report designed to help the students see what kinds of questions scientists ask when they see a report. Since Dr. M was in contact with another group of students doing similar things, he proposed that Ms. H's class join in the discussion that they were already mediating with their classroom collaboration site.

Soon to Come

Suggestions for more collaboration activities
Astronomy resource sites
Assessment Activities

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