Lesson Protecting the Mummified Troll

Quick Look

Grade Level: 7 (6-8)

Time Required: 45 minutes

Lesson Dependency: None

Subject Areas: Physics, Science and Technology

Photo shows a silver hooded metal box mounted on a street pole.
A closed-circuit surveillance camera near a German train station.
Copyright © Florina Hurlbrink, Wikimedia Commons http://commons.wikimedia.org/wiki/File:Surveillance_camera_Train_station_NSMA_Schnaittach_DE.jpg


Students are introduced to the (hypothetical) task of developing an invisible (non-intrusive) security system to protect the school's treasured mummified troll! Solving the challenge depends on an understanding of the properties of light. After being introduced to the challenge question, students generate ideas and consider the knowledge required find solutions. They watch a portion of the "Mythbuster's Crimes and Myth-Demeanors" episode ($20), which helps direct their research and learning toward solving the challenge. They begin to study laser applications in security systems, coming to realize the role of lasers in today's society.

Engineering Connection

Lasers are used in many engineering applications and it is essential for engineers to understand the properties of light and the physics behind them. Biomedical engineers use and design lasers in therapeutic settings, including ablation and coagulation, and diagnostic settings, with optical trapping / micromanipulation of cells and optical imaging through optical biopsies. Mechanical engineers use lasers in design and manufacturing for precision cutting and welding purposes. Other engineers incorporate lasers into such everyday items as CD reader/writers and security system sensors.

Learning Objectives

After this lesson, students should be able to:

  • Explain the challenge problem.
  • List what information might be needed to address the problem.
  • Group together similar areas of knowledge needed for the challenge.

This lesson also meets the following Tennessee Foundations of Technology educational technology content standards: 3.0, 5.0, 6.0, 7.0 and 8.0; see https://www.teta.org/

This lesson also meets the following National Science Education Standards (NSES) teaching standards: A, B, C, D, E, F; see https://www.nap.edu/topic/

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

  • Brainstorming is a group problem-solving design process in which each person in the group presents his or her ideas in an open forum. (Grades 6 - 8) More Details

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  • Illustrate the benefits and opportunities associated with different approaches to design. (Grades 6 - 8) More Details

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Have you ever thought about how you could possibly protect your most prized possession? Or how to know if your little sister went into your room while you were away? Have you ever wondered exactly how security systems work? Or how many different types of security systems exist? What if this happened:

A mummified troll was discovered this past summer at our school and it has generated lots of interest worldwide. The principal asked us, the technology classes, to design a security system that alerts the police if someone tries to steal our most prized possession. How can we construct a system that allows visitors to view our artifact during the day, but invisibly protects it at night in a cost-effective way?"

Over the next two weeks, it is our task to solve this engineering challenge assigned by the principal.

Are you ready to think like engineers?!? To accomplish our goal, we must first consider what we already know and what we think we must learn. Then, we will watch an episode of the Discovery Channel's show MythBusters! Listening to an expert's opinion on security systems will help us improve upon our initial ideas, so we can move closer to solving the engineering challenge. After modifying our initial thoughts, we will spend a few days learning the properties of light and exploring various demonstrations to understand exactly how light can be used to protect a mummified troll. So, in just a few weeks, we will have the ability to think like engineers and solve our engineering challenge.

For today, let's stick to exploring our mummified troll challenge!

Lesson Background and Concepts for Teachers

Legacy Cycle Information

This lesson covers the Challenge, Generates Ideas, and Multiple Perspectives phases of the legacy cycle, during which students begin to brainstorm ideas and organize the information they deem necessary to solve the challenge. Through the video, students are introduced to the input of a professional, which helps to guide their learning.

Delivery Information

Begin by introducing students briefly to the legacy cycle and how they will learn the concepts of light. This helps them understand why they are going through each phase of the cycle. Next, read the challenge question aloud to the class. Then, conduct the associated activity The Mummified Troll: Devising a Protection Plan (in which students first record their personal thoughts and ideas on a worksheet, then the class generates a list on the board of concepts to consider in solving the challenge question, then students generate a list of knowledge areas and categorize the concepts into three comparative knowledge areas: basic properties of light, laser types / applications, and the construction of the laser security system).

After ideas have been generated, show the MythBusters: Crime and Myth-Demeanors episode and give students time to brainstorm additional ideas for needed information.

Associated Activities

  • The Mummified Troll: Devising a Protection Plan - Students are introduced to the concepts of the challenge. They generate ideas for solving the grand challenge first independently, then in small groups. As a class, they compile their ideas with a visual as a learning supplement.

Lesson Closure

(Show the Mythbusters episode video. Conduct a class or team brainstorm session[s].)

What have we learned, from the experts that can help us improve our initial ideas on creating a security system to protect the mummified troll? What else should we learn about so we can solve this engineering challenge?

(Give students some time to capture the discussion ideas in their journals, as described in the post-lesson assessment in the Assessment section.)


Post-Lesson Assessment

Journaling: Ask students to compose answers in their journals to the following questions:

  1. How might light relate to a security system?
  2. What properties of light might be relevant to answering this question?
  3. Do you have a security system at home? How does it work?
  4. What are some characteristics the security system must have to keep the troll safe?

Additional Multimedia Support

Purchase the 50-minute episode titled, "MythBusters: Crimes and Myth-Demeanors – Part 1," online fromAmazon: https://www.amazon.com/gp/product/B001NY3UJ0/ref=dv_dp_ep17


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© 2013 by Regents of the University of Colorado; original © 2008 Vanderbilt University


Terry Carter, Meghan Murphy

Supporting Program

VU Bioengineering RET Program, School of Engineering, Vanderbilt University


The contents of this digital library curriculum were developed under National Science Foundation RET grant nos. 0338092 and 0742871. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.

Last modified: June 30, 2019

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