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YOUR NAME |
Eric Anderson |
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LESSON TITLE |
Get the Drift? |
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GRADE LEVELS |
8-12 |
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TIME ALLOTMENT |
This lesson may be completed in six-eight 50-minute class periods, depending on pacing and ability of students. |
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OVERVIEW |
The emphasis on students acquiring scientific knowledge often overwhelms their understanding of how that knowledge came to be in the first place. Historical contexts and deep understandings of the nature of science are an essential component of scientific literacy. In this unit, students will discover how scientific theories change over time. The vehicle for the unit will be the development of the theory of plate tectonics. Students will engage in a jigsaw model of cooperative learning in a way that authentically simulates how scientists share information and build theories. Each student group will represent a different team of scientists. First, these teams "meet" in the year 1926, at a symposium on continental drift organized by Alfred Wegener, the lead proponent of the theory of continental drift. Student-scientists present a range of ideas and data - not all of it in support of the theory, and then debate the merits and shortcomings of the theory from a 1926 perspective. (In 1926, a real symposium actually took place. Scientists who attended the symposium went away feeling that there was great evidence for continental drift, but without a mechanism for the drift, the idea was not a viable theory.) Then, the unit fast-forwards to 1963. Recent advances in technology have revealed information about the structure of the earth that hints at a mechanism that can move continents, and the idea is revived, modified, and the idea of plate tectonics emerges. Today, plate tectonics is regarded as a viable theory, one of the fundamental "big ideas" in science that ties all of geology together and links it to climatology and evolutionary biology. |
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KEYWORDS
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Alfred Wegener continental drift scientific theories plate tectonics earthquakes volcanoes mountain building Note: It is assumed that the student has already learned about the surface processes related to earthquakes and volcanoes, and has learned about the properties of rocks and minerals. |
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LEARNING OBJECTIVES |
Students will be able to: Relate the occurrence of earthquakes and volcanoes to plate tectonics Explain the theory of plate tectonics. Model the development of theories by simulating historical science symposia. |
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STANDARDS |
Nevada State Standards: 18.12.6 Explain that scientific knowledge builds on previous information,& rarely are entire theories completely discarded in favor of new ones. 18.12.3 Investigate & explain how scientific innovations that were originally challenged are now widely accepted. 18.8.4 Explain that scientists may work in teams & some may work alone, but all communicate extensively with each other. 18.8.6 Explain that scientific knowledge is revised through a process of incorporating new evidence gained through continual investigation. 19.12.4 Distinguish between hypotheses, laws, theories & rules,& explain the level of their limitations. 22.8.3 Discuss scientific topics by paraphrasing, asking for clarification or elaboration, & expressing alternative positions using available multimedia resources. 13.12.8 Model & explain how the energy that propels the Earth’s lithosphere plates is dominantly a result of nuclear processes deep in the Earth. |
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MEDIA COMPONENTS |
Web Sites: See attached student sheets for student websites – the sites listed below are for teacher reference. Plate Tectonics The Birth of Plate Tectonics (3 pages) Evolution of Continents and Oceans (warning - this site has enormous, slow-loading, high-resolution graphic files so it might be best to “whack” the site first and store it on a local computer for students to view) Alfred Wegener biographical sites Alfred Wegener (1880-1930) A Science Odyssey: Alfred Wegener Alfred Wegener: A Man Ahead of His Time The Meteorologist Who Started a Revolution Historical Perspectives Plate Tectonics: The Rocky History of an Idea Continental Drift (first in series of pages outlining the history of plate tectonics) The Great Continental Drift Mystery Video: Miracle Planet: The Heat Within (Annenburg) |
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MATERIALS |
Student
Materials
Per cooperative group of 3-4: Simulation prepsheets and abstract/review sheets; colored pencils; plain white paper; blank overhead transparencies and markers; any other construction/presentation materials you can make available (e.g., scissors, tape, glue); lab journal (student provided); lab/activity guides for each group; theatrical props (costumes, flags, lab coats, etc., provided by students) Computer ResourcesPer cooperative group of 3-4 students: One multimedia computer workstation with Internet access. Minimum recommendations: Macintosh PowerPC series running system 7.0 or higher, or a 486 IBM-compatible PC running Windows 3.1 or higher. Either platform should have Netscape Navigator or Internet Explorer. Some sites require Java, and others require Shockwave plug-ins. For group presentations, Microsoft PowerPoint and Microsoft Word are useful (but not required), as is a printer. Video ResourcesThe Miracle Planet: Heat From Within Underwater flyby – download this from Seawifs.gsfc.nasa.gov:80/OCEAN_PLANET/HTML/oceanography_flyby.html |
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PREP FOR TEACHERS |
Computer setup: bookmark the web sites listed above and load any plug-ins that are required. Be sure that you have the appropriate browser installed. Print preparation: Run off copies of the simulation prep sheets and symposium abstract/review sheets for each student. Special Note: The first symposium on Continental Drift is an activity from the 9th grade edition of Prime Science. It is copyrighted, and so you must obtain copies or permission to make copies from Kendall Hunt Publishing Company. However, the information listed in the symposium prep sheet should be sufficient for you to re-create the activities and avoid unethical plagiarism. If you want to "ham it up," then obtain early 20th century clothes and dress up as Dr. Wegener to introduce the unit. If you are a female teacher, you may wish to introduce the unit as an associate or relative or Dr. Wegener. Focus for Media (Internet): As preparation for acquiring information from the Internet, hand out symposium briefing guides (attached) which explain the nature of the information they are to collect. Then distribute the activity guides, which students conduct to reinforce their Internet information. |
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INTRODUCTORY ACTIVITY: SETTING THE STAGE |
Day One: Introduce the unit and distribute the symposium briefing guides and activities. If you have not done so already, put the students into groups. (It is recommended that you use groups of four students, each group composed of a high learner, and low learner, and two middle learners. For a useful tool for evaluating the cognitive levels of your students, see the NSTA Publication What Research Says to the Science Teacher: The Process of Knowing.) Show the first clip from "The Heat Within" (Note: all time references are relative to the appearance of the title at the beginning of the program, following the narrated introduction. The times are approximate, and will vary from VCR to VCR). FAST FORWARD to 12:05 MUTE PLAY from 12:05 to 12:45. (Start cue: Narrator says "..nowhere on land are fissures more common than in Iceland." End cue: view of fissure dissolves to graphic showing the geographic distribution of fissures throughout Iceland) While the film is playing, tell students they are looking at an area in Iceland. Ask, "What do you think this is?" (It’s a large crack in the ground.) "What do you think caused this crack?" (Accept all answers.) FAST FORWARD to 30:47 SOUND ON PLAY from 30:47 to 36:20 (Start cue: scene shows vistas of the Himalayas, and narrator says, "The lofty peaks of the Himalayas reach through the clouds." End cue: Narrator says, "...are found near the top of the world’s highest mountains. STOP: Ask, "How could ocean sediments and fossils of sea life end up in the tallest mountain range on Earth?" (Accept all answers) Ask the students, “How do you think mountains, earthquakes, and volcanoes form?” Accept all answers and compile them on an overhead chart, chalkboard/whiteboard, or chart paper. (Save these responses for later – alternatively, you could assign these questions in a written pre-test). Introduce the unit as Dr. Wegener. Say, "Hello, I am Alfred Wegener. I’d like to introduce you to the 1926 [name of school] Academy of Science Symposium on Continental Drift. We are fortunate to have gathered here scientists from around the globe." At this point, while students stare at you as if you’ve lost your mind, introduce each team of scientists. Be sure to announce their nationalities. Describe Wegener’s theory of continental drift. Use the fit of South America and Africa as an example of how continents were once together (place cutout shapes on an overhead and demonstrate). If students object to the way that these two continents are not fitting perfectly, remind them that over time erosion changes the shapes of coastlines, and that if we consider the continental shelf to be the actual edges of continents, then they do fit together much better. Define theory for the students. Use the following, from the National Academy of Science’s Teaching About Evolution and the Nature of Science: A theory is a well-substantiated explanation of the natural world that incorporates facts, laws, inferences, and tested hypotheses. Explain to students what the terms well-substantiated, facts, laws, inferences, and tested hypotheses mean. Review the assignment with students and tell them how they will be graded (see rubric that is provided in the student simulation guide). Make sure they are clear as to their expectations. |
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LEARNING ACTIVITIES |
Day Two: Allow students time to create brief presentations. Try to restrict them to multimedia resources of the 1920’s - there were overhead projection units then, so transparencies are okay, as well as any poster-style graphics. Day Three: Symposium One presentations. Use a grading rubric (attached) to evaluate presentations; alternatively, you may distribute this and have students grade other students’ presentations and construct a fair way to average those scores with the overall grade. Day Four: Introduce Symposium Two. Explain to students that in 1926 continental drift theory died for lack of a mechanism. Tell the students that we will now fast-forward in time to the early 1960’s, when a rich new set of data allowed scientists to begin constructing the structural history of the Earth. Video Component: The Miracle Planet: Heat From WithinFAST FORWARD to 13:58 SOUND ON. Tell students they are going to see what it looks like when lava comes out of the Earth under the ocean PLAY from 13:58 to 14:45. (Start cue: Shots of lava extruding underwater. Stop cue: Picture zooms shut, beginning to show old pillow lavas on the ocean floor.) PAUSE: Tell students they are now going to see what the ocean floor looks like near the middle of the Atlantic Ocean MUTE PLAY from 14:45 to 15:09 (Start cue: The end of the lava extruding clips, beginning of showing pillow lavas on the ocean floor. Stop cue: A wipe right transition from pillow lavas to a shot of the submersible Alvin.) PAUSE:
Ask students what they think they are seeing (pillow lavas)
Ask, Day Five: Allow time for students to prepare presentations. This time, allow students to compile and present PowerPoint graphics, even though this technology did not exist in the 1960’s. Day Six: Symposium Two presentations. Evaluate as before. |
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CULMINATING ACTIVITY |
Day Seven: The Big Picture. Video Component: The Miracle Planet: Heat From Within Focus for Viewing: Review the earlier questions: What causes earthquakes, volcanoes, and mountains? How can pillow lavas exist in the middle of the Atlantic Ocean, and rifts in Greenland? How did ocean sediments and fossils get on top of the Himalayan mountains? SOUND ONFAST FORWARD to 17:48 CUE: Narrator: PLAY: 17:48-21:02 (Start cue: Narrator says, "The heat from within our planet is constantly flowing toward the surface." Stop cue: Narrator says, "...continuously radiating heat from within our planet.") STOPTell students that in one place on Earth, a continent is splitting apart. This is happening in Africa. FAST FORWARD to 27:46 PLAY 27:46-29:30:47 (Start cue: A 3-D graphic of the interior of the Earth. Stop cue: Narrator says: "50 million years from now, the map may show an African Sea.") STOP Tell students that the crust of the Earth doesn’t just pull apart. FAST FORWARD to 36:02 SOUND ON PLAY from 36:02-42:03 (Start cue: Narrator says, "This is a computer-generated view of the Earth." Stop cue: Narrator says, "...until they formed the tallest range on Earth.") STOP: Explain the theory of plate tectonics to students in its entirety. Help them build this big idea from the groups that presented the day before, and fill in any gaps in their understanding with diagrams and discussion. Distribute the abstract/review sheet and ask students to work on this in their groups. Collect this as a summative assessment. |
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CROSS-CURRICULAR EXTENSIONS |
Art: Have students build papier-mâché models of plate boundaries Music: relate seismic waves to acoustical waves Social Studies: explore the issues of living in tectonically active places Biology: research the impact of plate tectonics on the evolution of species |
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COMMUNITY CONNECTIONS |
Have students assess the tectonic setting of their community, and examine the emergency preparedness of the community for events such as earthquakes and volcanoes. |
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STUDENT MATERIALS |
Per team of four (1 set for EACH symposium): 1 manila folder, 4 simulation guides, 4 abstract/review sheets, presentation materials (may include colored pencils, crayons, poster board, plain white paper, scissors, computers with PowerPoint - typically, I provide every "grade school construction" materials I have available) To re-create the symposium 1 guides used in this activity, use the following as a guideline: There are up to 8 teams of students, representing 8 different countries. The scientists in these countries are presenting the following research ideas:
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