Prior to this, students have learned about REMUS and how it is deployed to study the behavior of white sharks. Additionally, they learned that electromagnetic reception was the primary method that sharks use to sense the world around them, leading students to wonder if white sharks are bothered by REMUS.

In this lesson, students will construct claims about the ability of white sharks to detect the electric and/ or magnetic fields produced from REMUS. Students will investigate the strength of a magnetic field that is produced by a current and how this magnetic field can interact with an additional magnet to create a motor. To do this, students plan and conduct an investigation to understand how fields are produced, deciding on variables and measurements to be recorded, and utilize their understanding of modeling complex and microscopic structures and systems to help them visualize how their function depends on the composition and relationship among parts. They also analyze many complex natural structures and systems to determine how they function and apply understanding that structures can be designed to serve particular functions by taking into account properties of different materials. Students build on their understanding of magnetic fields by engaging deeply in arguing from evidence, and compare and critique arguments on the same topic, provide and receive critique, and use evidence and scientific reasoning to refute an explanation.

In the next lesson, students will learn how tags use acoustic (sound) and radio waves to transmit to a receiver such as REMUS.

Throughout the lesson, a flag () denotes formative assessment opportunities where you may change instruction in response to students’ level of understanding and making sense of phenomena.

4. As students identify areas where additional information may be needed in order to have a strong explanation, let them know you have readings that may be useful. Point out also that the Ocean Portal website they used in Lesson 8.4: REMUS referred to electric fields as well as magnetic fields, so you have found some articles that will discuss both. Arrange students into groups of 4 and give each student in the group one of the following articles: 8.5.G1: Snout Goo May Help Sharks Sense Prey, 8.5.G2: Scientists Repel Sharks–to Save Them, 8.5.G3: A Shark’s Sixth Sense, and 8.5.G4: A Biological Function for Electroreception in Sharks and Rays.

   Write the following codes on the board for the students to use as they read their article. Have them underline and code the following:

   “SA”:
   Shark Anatomy–basic information about the structure/function of a shark
   “EE”:
   Electrical Evidence–evidence that supports an understanding of how sharks are influenced by electric fields
   “ME”:
   Magnetic Evidence–evidence that supports an understanding of how sharks are influenced by magnetic fields

   Differentiation: At your discretion, put students into expert groups if they need peer support while working through the readings. Make sure that students needing language support are focusing on the content of the article rather than words that are unclear. Ask students to skim their article and highlight any words whose meaning is uncertain. Before students read the articles, offer to have students look up the meaning of highlighted words and/or as a whole class go over words that might cause some confusion or prevent them from moving forward with the reading.

5. When students have completed their reading, arrange students into expert groups with others that read the same article. Record the following on the board for students to see:

   Sharks are influenced by electric fields.

   Sharks are influenced by magnetic fields.

   Sharks are influenced by BOTH magnetic and electric fields.

   1. Ask students, in their expert groups, to compare their coding and discuss which claim they think their evidence supports best and why. Encourage students to record this discussion (especially evidence identified) in their Science Notebook.
   2. Students return to their home group and share their expert findings with their group. (Each student should have read a different article.)
      • Direct students to share what they found. Emphasize that everyone will have a chance to share before anyone can discuss or ask questions about how their evidence supports the claim they picked. During sharing, encourage students to record a couple of “big ideas” from each report.
      • After groups have shared, have a brief class discussion asking students to recall what is required for something to be considered quality evidence and a quality source.
      • Then invite groups to hold a discussion on the reading. Direct students to ask questions about the evidence of others, making sure to ask them about the source of the material. What makes for quality evidence? Why would one claim be preferred over another? Encourage students to add anything they feel is important from the discussion to their Science Notebook.
      • Ask groups to then come to consensus on which claim their evidence best supports (which one best addresses the question). If there are students who need help, guide groups to recall that that their conversation needs to consider both the quality of the evidence that was gathered and discussed, as well as which claim (sharks are influenced by electric fields, or sharks are influenced by magnetic fields) had the fewest counters to said evidence (rebuttal). Students can make additional notes in their Science Notebook about which claim they are supporting and any subsequent evidence.

      During discussions, encourage students to use discussion norms such as wait time, encouraging others to say more, asking for evidence, paraphrasing or repeating, adding on, etc.

TEACHER NOTE

The articles (8.5.G1–8.5.G4) were intentionally chosen from a wide range of sources, from a transcribed radio interview to an academic article. The reading levels of the articles range from 6th grade through high school. It may be best to arrange that students receive articles that are most appropriate for their reading levels. In case differentiation by reading level is needed for students, they are arranged in increasing complexity of reading level (e.g., 8.5.G1: Snout Goo May Help Sharks Sense Prey is the easiest and 8.5.G4: A Biological Function for Electroreception in Sharks and Rays is the most difficult).

6. Ask students to discuss which part of REMUS they think contributes the most to the white shark being able to sense it in the water. If students do not remember the parts of REMUS ask them to refer back to their Science Notebook notes on REMUS (taken in Lesson 8.4: REMUS, Part 7.b); they can also visit http://www.whoi.edu/osl/sharkcam again if needed.
   • Have students make a list in their Science Notebook of the parts of REMUS in the order that they think a white shark can sense them. (A rough model can replace a list depending on student preference or need as a way to differentiate.) Have students record/identify what sense they think the white shark is using to detect the respective parts they identified, and have the students pay particular attention to electroreception. If students do not automatically do this, encourage them to think about internal components as well as external; for example, if students identify the propeller, ask what makes the propeller work (internal motor).
   • Ask a few students to share their lists/models with the class. Be sure to choose one student that identified a motor.

   TEACHER NOTE

   The next part of this sequence will focus on building a simple motor for better understanding of the scientific properties that govern the function of a motor and to establish the connection between electricity and magnetism. For your reference, the actual motor used within REMUS is extremely complex, but we are keeping it simple to build student understanding of magnetic fields in context.

7. Establish that students are going to focus on just one of the aspects of REMUS they identified, the motor, and how it uses electricity (and, as students will soon discover, magnetism).
   1. To first establish the connection between electricity and magnetism and to introduce the idea that an electric current creates a magnetic field, have students work in groups to create an electric current by connecting the ends of a long straight wire to each end of a D cell (or 9-volt) battery and lay the wire flat on the table. This creates a magnetic field. If a student in the room already knows how to do this, allow this student to introduce the idea. If possible, have these materials for each group so each may build the circuit. Be sure to demonstrate this at the front of the room as well.

   

   2. Invite a student from each group to bring a compass up to the wire in several locations. Students can also do this at their tables if materials are available, but focus the conversation from the front of the room. Ask students to record observations in their Science Notebook. If possible, recreate the set-up under a document cam so there is opportunity for group discussions when manipulating the set-up. Encourage students to try out several things. (Make sure that students are bringing the compass to both sides of the wire and different distances from the wire.) Students should observe the following phenomena:
      • The needle of the compass will spin when brought close to the wire.
      • The needle of the compass will spin in different directions depending on which end of the wire it is near.
      • The rate of spin of the compass needle will change depending on how far it is located from the wire.
   3. Put the compass away and ask another student to bring a small magnet close to the wire. Students can also do this at their tables if materials are available, but focus the conversation from the front of the room. Ask students to make additional observations of the interaction between the wire and the magnet.

      If students are struggling, the following questions can help to guide students to build understanding of and explain the phenomenon:

      • What is the effect of holding a magnet near the wire?
      • Are the wire and magnet attracting or repelling?
      • Is there a way to change the interaction (from repel to attract or vice versa)?
      • Does the distance between the magnet and the wire change the strength of the attraction/repulsion?

      (For teacher reference, when an electric current travels through a conductor, in this case a wire, a weak magnetic field is produced by that current. The magnetic field produced will deflect the compass needle. The arrow of the compass will point in the direction of the magnetic field.)

   TEACHER NOTE

   

   If there is a way to allow the wire to be perpendicular to a surface where the compasses are located, students can observe that the needle of each compass actually points to the compass next to it in a circle around the wire. While it is only necessary for students to understand that an electrical current produces a magnetic field, it is a nice “next step” for students to see that there is a pattern to the magnetic field that is produced. If the strength of the current is not enough to produce visible changes of the compass direction, this can be addressed by using a 9-volt battery instead of a D cell battery. Additionally, students could make an electromagnet, which will produce a stronger magnetic field. In either case, some safety precautions should be taken if a stronger battery or electromagnet is used, as they heat up quickly. Students can use erasers as an “insulator” between their fingers and circuit components to avoid feeling heat.

8. Following these observations, let students know they will now be designing their own investigation to help answer some of their questions. Have a discussion with students about what constitutes a fair test and variables (as this should be prior knowledge). If students struggle, you can prompt them with one or more of the following questions or statements:
   • If we want to know if something has had an effect, what would be a fair test?
   • Why should we test only one thing at a time?
   • Are there aspects of a test that don’t change? Why is it important to have those?
   • When students begin describing the parts of the investigation that “we” manipulate, confirm that these are called independent variables.
   • When students describe things that change because of that manipulation, confirm. that these are called dependent variables.
   • When students describe something we would keep constant, confirm that this is a control.
9. Distribute 8.5.H1: Motor Apparatus and materials to students. Ask students for their ideas about motors–why we need them, why we test them, and how testing motors can help us explain why the white shark attacked REMUS.
   1. Ask student groups to come up with four different variables to test for the motor apparatus. Here are some of the variables that students might elect to test:
      • Number of turns
      • Diameter of the turns
      • Strength of the magnets
      • Distance the magnet is away from the coiled wire
      • Gauge of the wire
      • Strength of the battery (This might require changing the apparatus to accommodate the new battery)

   TEACHER NOTE

   The following variables would be more suited to highly motivated students as they are either not as directly observable or require a more sophisticated understanding of the variable as to how it is effecting change; diameter of the turns and gauge of the wire.

   2. Once students have established what they would like to test and begun planning their investigation, ask them to record the following in their Science Notebook. Consider allowing students who need literacy support to work in pairs; later you can make a copy of the work completed for the other student to add to their Science Notebook.
      • What question of theirs are they testing? (This doesn’t necessarily need to be a formal research question; it may simply be a question that emerged in the discussion above that the group would like to test.)
      • Explain their test; give a brief description of what they will do.
      • List variable(s) (independent and dependent) and control(s).
      • Specify the type of data they will measure and how.
      • Make a prediction of what they think will happen (with rationale).
      • Record observations. (How will they record observations/data?)

      Students can collaboratively discuss, but each should maintain their own record of the plan in their Science Notebook, in addition, students are realistically doing several tests; this is intended to be a “rough” plan in their Science Notebook to track what they are doing and what they observe.

      Encourage highly motivated students to develop even more tests.

   3. Once groups have recorded their plan, allow access to materials to begin testing their plan. Instruct students to record their findings in their Science Notebook.
   4. After groups have done their investigations and had time to make meaning in their Science Notebook (via small models and/or notes), have a class conversation about how the two magnetic fields were interacting. Depending on the types of investigations that students conducted, some of the questions generated might sound like the following:
      • Were the magnetic fields attracting or repelling? What is your evidence?
      • What caused the motor to spin slower/faster?
      • How do you think this compares to the motor in REMUS?
   5. Ask students to record any aha moments about magnetic fields in their Science Notebook and what phenomena they could predict using the cause and effect relationship they just discovered. Inform students that this will be used for sticky note feedback (as described in Lesson 8.2: Fossil Evidences).

When showing a short video, it’s often helpful to students to watch the video once to get a sense of the purpose. Showing the video a second (and sometimes third) time allows students to focus on important details that can be recorded in their Science Notebook and discussed.

To accommodate students who need help with reading tasks, ask the class to skim the article first, and identify any words that might need clarification. Clarify the directions, then ask students to do a group read (have one person in the group read the article out loud), but encourage students to withhold group discussions until everyone has had a chance to do their own thinking and make notes in their Science Notebook first, then discuss with their group, and revise Science Notebook work accordingly.

During literature circles, plan extra accommodations for those who need literacy support. These students can be paired with a peer for the initial attempt at the reading. When expert groups decide on their three pieces of information, encourage the class to allow those that are quiet to speak first. Have the expert group verify that all have information recorded in their Science Notebook before rejoining their home groups.

By seating students in groups (groups of 4 work well) and encouraging regular conversation, students have time to interact more with content and naturally help those that need more support. Use of 8.1.H2: Scientist Communication Survival Kit helps to make sure that students who don’t feel comfortable sharing (often because of language, literacy level, uncertainty of content knowledge, etc.) are prompted to do so in a supportive way.

Use of a sense-making Science Notebook supports student language development, conceptual development, and metacognition. Students should be prompted to use their Science Notebook for

• prior knowledge of phenomena,
• exploration of phenomena and data collection,
• making sense of phenomena, and
• metacognition.

By writing about topics in their Science Notebook BEFORE discussing, second language learners and low language students can gain confidence and organize their thoughts before speaking in front of a group. Also, sharing ideas in a small group throughout the rest of the lesson lowers the affective filter of low language students. Having students work in teacher-selected partnerships or groups allows you to match students in a way that both are being supported. Advanced students have the opportunity to explore additional questions that arise.

Consider providing sentence frames for low literacy and second language learners. The use of graphic organizers can help struggling students manage Science Notebook work.

As this lesson is rich with discourse opportunities, consider pairing second language learners with a “language broker” (another student who is bilingual in English and the student’s home language) to allow these partners to first discuss ideas in their home language. Monitor this paring and provide additional language support as needed.

For students new to a socratic seminar and in need of speaking support, review the discussion norms and questions from “Socratic Seminars in Science Class” (Chowning, 2009). Consider including additional talk moves (for ideas, see Talk Science Primer, Michaels and O’Connor, 2012). As students begin to share ideas, use specific prompts such as, “Can you say more about that,” “What do you mean by that,” and “Can you give an example.” Asking another student in the seminar to repeat what the speaker said, or to add on to what the speaker said is also helpful. Once students understand the structure of the seminar, these prompts should come less from you and more from the students participating in the seminar.

Boise State College of Engineering. (2011). How to Make a Simple DC Motor. Retrieved March 4, 2020, from http://coen.boisestate.edu/k-12/files/2011/06/How-to-Make-a-Simple-DC-Motor.pdf

Chowning, Jeanne Ting. (2009). Socratic Seminars in Science Class. The Science Teacher, 76(7), 36-41. Retrieved from https://learningcenter.nsta.org/resource/?id=10.2505/4/tst09_076_07_36

Conover, Emily. (2106, June 30). Snout goo may help sharks sense prey. Retrieved from https://www.sciencenewsforstudents.org/article/snout-goo-may-help-sharks-sense-prey

Daniel, Ari. (2012, April 4). Scientists Repel Sharks – to Save Them. Retrieved from https://www.pri.org/stories/2012-04-04/scientists-repel-sharks-save-them

Hopkins, Carl D. (2010, March 12). A Biological Function for Electroreception in Sharks and Rays. Journal of Experimental Biology, 213(7), 1005–1007. https://doi.org/10.1242/jeb.034439

KQED (2016, August 11). How Do Sharks and Rays Use Electricity to Find Hidden Prey? | Deep Look. YouTube. Retrieved from https://www.youtube.com/watch?v=JDPFR6n8tAQ

MacIver, Malcolm. (2009, July 31). A Shark’s Sixth Sense. Retrieved from https://helix.northwestern.edu/article/sharks-sixth-sense

Michaels, Sarah & O’Connor, Cathy. (2012). Talk Science Primer. TERC. Retrieved from https://inquiryproject.terc.edu/shared/pd/TalkScience_Primer.pdf

Carl D. Hopkins discusses Adrianus J. Kalmijn’s 1971 paper entitled ‘The electric sense of sharks and rays’. A copy of the paper can be obtained from http://jeb.biologists.org/cgi/content/abstract/55/2/371

Woods Hole Oceanographic Institution (2016). Oceanographic Systems Laboratory Autonomous Underwater Vehicle, REMUS: Shark Cam, Retrieved from http://www.whoi.edu/osl/sharkcam