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COURTESY OF PATRICK RONEY, ALIREZA SHAHSAFI AND MIKHAIL KATS

February 1, 2020 Coating Provides

February 1, 2020 Coating Provides Infrared Camouflage

About this Guide

This Guide, based on the Science News article “Coating provides infrared camouflage,” asks students to explore the and potential technological applications of a material, discuss the various types of electromagnetic , analyze infrared images and research how infrared imaging is used across a range of fields.

This Guide includes:

Article-based Comprehension Q&A — These questions, based on the Science News article “Coating provides infrared camouflage,” Readability: 12.7, ask students to explore the physics and potential technological applications of a material. Related standards include NGSS-DCI: HS-PS4; HS-PS3; HS-PS2; HS-ETS1.

Student Comprehension Worksheet — These questions are formatted so it’s easy to print them out as a worksheet.

Cross-curricular Discussion Q&A — Students will watch a NASA video about the electromagnetic to learn about properties of the various types of radiation. Then, students will explore and discuss technologies that use specific types of electromagnetic radiation. Related standards include NGSS- DCI: HS-PS4; HS-PS3; HS-PS2.

Student Discussion Worksheet — These questions are formatted so it’s easy to print them out as a worksheet.

Activity: Seeing in Infrared

Summary: In this activity, students will analyze infrared images and then explore how infrared imaging is used across a range of fields of work. Skills include researching, evaluating, synthesizing and presenting . Related standards include NGSS-DCI: HS-PS4; HS-PS3; HS-ETS1.

Approximate class time: 1 class period to complete the discussion, research, presentations and debriefing as a class.

February 1, 2020 Coating Provides Infrared Camouflage

Article-based Comprehension, Q&A

Directions for teachers: After your students read “Coating provides infrared camouflage,” ask them to answer the following questions.

1. How do infrared cameras work?

Infrared cameras measure the amount of thermal radiation an object emits within the infrared region. The measurements are used to estimate the object’s .

2. What is the relationship between an object’s temperature and the brightness of the thermal radiation it emits? What do physicists call this relationship?

The hotter an object gets, the brighter its thermal radiation. This relationship is called the Stefan- Boltzmann law.

3. Name one way you can see this relationship in everyday life?

When you turn on an electric stove, the heating coils glow brighter.

4. In what way does samarium nickel oxide appear to defy this relationship?

When samarium nickel oxide is viewed by an infrared camera in certain of infrared , the material does not get brighter as its temperature increases.

5. What properties of the material explain this defiant behavior?

At the described, the material switches from an insulator to a metal and its tendency to emit thermal radiation decreases. This decrease in emissivity counteracts the increase in brightness from the Stefan-Boltzmann law.

6. How did scientists apply samarium nickel oxide? What did they apply it to and what data did they collect?

Scientists made a thin coating of samarium nickel oxide and used it to coat samples of sapphire. The scientists imaged heated samples with infrared cameras to see how brightly the samples glowed.

7. Why does the author describe the coating as a potential “camouflage”?

Camouflage is a disguise that allows people or objects to hide. The material’s ability to maintain a constant brightness despite increasing temperature could be used to hide people or objects from infrared cameras, which image things based on the thermal radiation they emit.

8. Describe two limitations of using samarium nickel oxide as a camouflage.

The temperature range in which the material’s brightness stays mostly constant is from 105° degrees Celsius to 135° Celsius — too high to hide people from detection by infrared cameras. Plus, the camouflage effect applies only at certain infrared wavelengths; cameras looking at different wavelengths would detect the change in brightness.

9. How does applied physicist Mikhail Kats plan to overcome one of the limitations?

Kats suggests testing alloys of samarium nickel oxide. These materials may have different properties and so show the camouflage effect at lower temperatures.

February 1, 2020 Coating Provides Infrared Camouflage

Student Comprehension Worksheet

Directions: After reading “Coating provides infrared camouflage,” answer the following questions.

1. How do infrared cameras work?

2. What is the relationship between an object’s temperature and the brightness of the thermal radiation it emits? What do physicists call this relationship?

3. Name one way you can see this relationship in everyday life?

4. In what way does samarium nickel oxide appear to defy this relationship?

5. What properties of the material explain this defiant behavior?

6. How did scientists apply samarium nickel oxide? What did they apply it to and what data did they collect?

7. Why does the author describe the coating as a potential “camouflage”?

8. Describe two limitations of using samarium nickel oxide as a camouflage.

9. How does applied physicist Mikhail Kats plan to overcome one of the limitations?

February 1, 2020 Coating Provides Infrared Camouflage

Cross-curricular Discussion, Q&A

Directions for teachers: Use this exercise to introduce or review the with your class. Begin by showing the NASA video “Introduction to the Electromagnetic Spectrum.” Students should work with a partner through the prompts in “Properties of electromagnetic radiation.” Example answers are given. Then, students should choose a specific type of electromagnetic radiation to explore and research a technology that uses their chosen type. They can use the prompts in “Applications of technology using electromagnetic radiation” to prepare and give a brief presentation to their classmates.

Directions for students:

Properties of electromagnetic radiation Watch NASA’s “Introduction to the Electromagnetic Spectrum,” and answer the following prompts with a partner. Make sure you discuss the relationships between properties of electromagnetic radiation with your partner. Use additional resources if necessary. For instance, you could look up a diagram of the spectrum, such as this one provided by NASA. 1. Define the following terms:

Electromagnetic radiation (make sure to include the name of each type): Waves with electrical and magnetic properties that carry from one place to another. Classified by , the types of electromagnetic radiation are gamma rays, X-rays, , visible light, infrared, and radio waves. Wavelength (and an appropriate unit used to measure it): The between two consecutive crests or toughs of a wave, typically measured in meters (m). (and an appropriate unit used to measure it): The number of crests that pass through a certain point in one second, typically measured in (Hz) or waves per second. The (and an appropriate unit used to measure it):

The speed at which electromagnetic waves travel in a . The speed of light is typically measured in meters per second, and is equal to 3.0 x 108 m/s for all types of electromagnetic radiation.

2. Are the wavelength and frequency of electromagnetic waves directly or inversely related? Explain.

Wavelength and frequency are inversely related. As the wavelength gets longer, the frequency gets smaller — fewer waves will pass through a certain point in a second — and vice versa.

3. Are the frequency and energy of electromagnetic waves directly or inversely related?

Energy and frequency are directly related. As the energy increases, so does frequency — more waves will pass through a certain point in a second. As the energy decreases, fewer waves will pass through a certain point in a second.

4. Based on your answers to questions No. 2 and No. 3, what is the relationship between electromagnetic waves’ wavelength and energy?

Since energy and frequency are directly related, and frequency and wavelength are inversely related, wavelength and energy must be inversely related. As a wave’s energy grows, its wavelength gets shorter, and vice versa.

5. To better understand how different types of electromagnetic radiation relate to each other, rank gamma rays, infrared, ultraviolet and radio waves in order of increasing:

Wavelength Gamma rays, ultraviolet waves, infrared waves, radio waves

Frequency Radio waves, infrared waves, ultraviolet waves, gamma rays

Energy Radio waves, infrared waves, ultraviolet waves, gamma rays

6. What property is the same across all types of electromagnetic radiation in a vacuum?

All types of electromagnetic radiation travel at the same speed in a vacuum, the speed of light.

Applications of technology using electromagnetic radiation With your partner, choose a type of electromagnetic radiation and research a technology that uses that specific type of radiation. Then, answer the questions below using NASA’s “Tour of the Electromagnetic Spectrum” and outside resources if necessary. The Science News archive is one of many useful resources. Use your answers to give a brief presentation on the technology to your classmates.

1. Does the video mention a technology you already knew about that uses electromagnetic radiation? Is there an application of that technology that was new to you, or surprised you? Explain.

2. Choose a type of electromagnetic radiation that you and your partner wish to explore and find a technology that uses this type of radiation. What is the technology called? What type of electromagnetic radiation does it use?

3. What is the goal or purpose of the technology?

4. Explain how the technology uses electromagnetic radiation.

5. Can this technology use only one type of electromagnetic radiation? Explain why or why not.

6. What are some other technologies that use your chosen type of electromagnetic radiation?

February 1, 2020 Coating Provides Infrared Camouflage

Student Discussion Worksheet

Directions:

Properties of electromagnetic radiation Watch NASA’s “Introduction to the Electromagnetic Spectrum,” and answer the following prompts with a partner. Make sure you discuss the relationships between properties of electromagnetic radiation with your partner. Use additional resources if necessary. For instance, you could look up a diagram of the spectrum, such as this one provided by NASA.

1. Define the following terms:

Electromagnetic radiation (make sure to include the name of each type):

Wavelength (and an appropriate unit used to measure it):

Frequency (and an appropriate unit used to measure it):

The speed of light (and an appropriate unit used to measure it):

2. Are the wavelength and frequency of electromagnetic waves directly or inversely related? Explain.

3. Are the frequency and energy of electromagnetic waves directly or inversely related?

4. Based on your answers to questions No. 2 and No. 3, what is the relationship between electromagnetic waves’ wavelength and energy?

5. To better understand how different types of electromagnetic radiation relate to each other, rank gamma rays, infrared, ultraviolet and radio waves in order of increasing:

Wavelength

Frequency

Energy

6. What property is the same across all types of electromagnetic radiation in a vacuum?

Applications of technology using electromagnetic radiation With your partner, choose a type of electromagnetic radiation and research a technology that uses that specific type of radiation. Then, answer the questions below using NASA’s “Tour of the Electromagnetic Spectrum” and outside resources if necessary. The Science News archive is one of many useful resources. Use your answers to give a brief presentation on the technology to your classmates.

1. Does the video mention a technology you already knew about that uses electromagnetic radiation? Is there an application of that technology that was new to you, or surprised you? Explain.

2. Choose a type of electromagnetic radiation that you and your partner wish to explore and find a technology that uses this type of radiation. What is the technology called? What type of electromagnetic radiation does it use?

3. What is the goal or purpose of the technology?

4. Explain how the technology uses electromagnetic radiation.

5. Can this technology use only one type of electromagnetic radiation? Explain why or why not.

6. What are some other technologies that use your chosen type of electromagnetic radiation?

February 1, 2020 Coating Provides Infrared Camouflage

Activity Guide for Teachers: Seeing in Infrared

Purpose: Students will explore how infrared radiation is used across a range of fields of work. Skills include researching, evaluating, synthesizing and presenting information, as well as analyzing images.

Procedural overview: After analyzing infrared images and answering associated questions, student groups will research how infrared imaging is used in a of their choice. They will then present their findings to the class.

Approximate class time: 1 class period to complete the discussion, research, presentations and debriefing as a class.

Supplies: Poster boards (one for each student research group) Various art supplies (markers, colored pencils, glue, scissors, etc.) Computer access A printer Printer paper A projector for introducing the activity (optional) Seeing in infrared student activity guide

Directions for teachers: Introduce students to the idea of infrared light by having them read “Coating provides infrared camouflage,” Readability: 12.7. The story mentions how infrared cameras can be used to search for medical conditions or detect sources of heat behind thin walls. But infrared imaging is used in many fields of work to study a variety of phenomena. In this activity, students will explore the various applications of infrared technology. (For a good introduction to infrared waves, check out this NASA site.)

Also, review basic information about the electromagnetic spectrum and about how light is absorbed, transmitted or reflected by objects. All objects also emit energy, in the form of electromagnetic radiation, based on their temperature. To ensure that students understand how to interpret an infrared image, look at the first and second series of images at “Transverse banding: a signature of potential turbulence.” These visuals were taken by a weather satellite. You can project the visuals or hand out color copies.

Explain that the images are from a weather satellite viewing Earth at infrared wavelengths. The images measure the emission at two wavelengths, 10.7 µm and 6.5 µm. Infrared light emitted at a wavelength of 10.7 µm is a measure of thermal heat. The infrared light at a wavelength of 6.5 µm can be used to estimate the amount of water vapor in the atmosphere.

As a class, answer the following questions about the visuals.

1. What main weather event are the infrared images showing?

The progress of a collection of thunderstorms as they move eastward across Nebraska and Iowa on July 19, 2016.

2. Instead of true-color, these visuals are called false-color images. What do you think this phrase means?

The colors used represent emissions of a specific wavelength and are not what we would see with our eyes or capture with a photograph.

colors in these images represent and how would you interpret them? 3. The first images measure emitted radiation at the 10.7 μm wavelength. Using the key, what do the The colors represent different amounts of light being emitted from the clouds based on their different temperatures. From the key at top, I would think that the black and red areas are warmest and green and blue are cooler.

wavelength. Using the key, what do the colors in these images represent and how would you interpret them? 4. The second images measure emitted radiation for the 6.5 μm The colors represent different amounts of water vapor in the air, indicating the locations of clouds. From the key at top, I would think that the green areas have the most water vapor, white areas have the second most water vapor and the blue areas have less water vapor but still have some water vapor.

5. A set of numbers are shown in both series of images, in yellow text in the first series and in blue text in the second. What does this data indicate?

The numbers represent places where pilots experienced turbulence.

6. How might these images be used?

These images might be used to identify the location and path of a storm system, to warn people, including pilots, of nearby weather, and to better study the formation and movement of storms and the turbulence they create.

7. How do images of Earth taken with a regular camera look different from these infrared images?

Images taken by a regular camera would correspond to what we see with our eyes — green vegetation, blue water, white clouds and snow and tan deserts — according to the wavelengths of light that these surfaces reflect within the visible region of the electromagnetic spectrum. These images instead use visible color to represent reflected wavelengths that are outside of the visible portion of the spectrum.

Explain to your students that infrared technology has many applications in a variety of fields of work. Ask students to form pairs or small groups and choose a field to explore. The website Cool Cosmos can provide some ideas, or students can select one of the fields listed below:

Astronomy Archeology Art history

Firefighting Geology Law enforcement Medicine Meteorology Military/tactical Oceanography Search and rescue Veterinary medicine

Instruct each group to find an infrared image that represents one example of how the technology is used in the field selected. Be sure to instruct students to use reputable sources (textbooks, peer-reviewed journal articles, websites ending with “.edu,” “.gov” or “.org,” and so on) when searching for images. One good resource is the Science News archive.

Students should select an image that has links to the source, so they can find out what technology was used to capture the image and how it works. The image should include text information about what is shown and, if possible, a scale or key. If the image does not include a key, students should explain how color is used in the image.

Groups should answer the student questions provided and use those answers to prepare a poster board about their image and how infrared technology has been applied. Students can set up their poster boards as “museum exhibits” in the library or your classroom. Have the groups prepare two-minute oral presentations describing the image they selected and the infrared technology application it represents. The rubric below (out of a total of 100 points) can help you evaluate each group’s poster and oral presentation.

Poster (60 points):

Is there at least one infrared image in color? (10 points) Does the infrared image include a written or visual key or student note explaining the coloring of the image? (10 points) Does the infrared image have an explanation of what it is, how it is created and what information is gained from it? (10 points) Is there an explanation of why this image is representative of infrared images in the selected field? (10 points) Is the importance of infrared imaging to the field expressed in words as well as images? (15 points) Does the poster include reputable sources? (5 points)

Oral presentation (40 points):

Was the infrared image and what it shows clearly explained? (10 points) Was the reason this image is representative of the field’s use of infrared imaging explained? (10 points) Was the importance of infrared imaging to the field explained? (10 points) Did each member of the team contribute to the presentation? (5 points) Did the group complete its presentation in the time allotted? (5 points)

After students share their presentations, answer these final questions to debrief as a class.

1. Which of the fields of work presented by the class use infrared technology for similar reasons? Make sure to include evidence to support any claims that you make.

Shared goals may include learning about the past, providing medical assistance to living beings, learning about the and helping to protect people or protect the planet from natural disasters. In order to support their answers, students should include details from peers’ presentations.

2. Which of the fields selected by other groups is most complementary to yours? Why? Explain the similarities and differences between how infrared imaging is used in the two fields.

3. Identify a possible project that people in two complementary fields could collaborate on with the help of infrared technology. How would that collaboration benefit each field?

Directions for students: People in many different areas of work use infrared technology to study a variety of phenomena. Infrared radiation is used to monitor volcanic eruptions and temperature trends across Earth. It can be used to detect the presence of drawings underneath paintings, to diagnose diseases and to locate people and animals trapped in fires.

In your small group, you will research how infrared technology is used in a field of your choice. Once you have completed your research by answering the questions that follow, you will create a poster board of your findings and present your research to the rest of the class. Your findings will explain how infrared technology is used in your selected field and why it is important.

Selecting a field that uses infrared images There are many applications of infrared imaging. Follow your teacher’s instructions to identify and select a field of work that uses infrared technology and answer the questions below.

1. What is the field your team chose and why are you interested in this field?

2. Summarize how you think infrared imaging might be used in this field.

3. Why might infrared in this field be an advantage over regular photography?

Selecting your infrared image Using reputable sources (textbooks, peer-reviewed journal articles, websites ending with “.edu,” “.gov” or “.org,” and so on.), find an infrared image that shows an example of how infrared imaging is used in the field you selected. The Science News archive is a good source.

Be sure to select an image that has links to the source, so you can find out what technology was used to capture the image and how it works. The image should include text information about what is shown and, if possible, a scale or key. If the image does not include a key, you should understand how color is used in the image. You may want to select an image that is accompanied by a regular photograph of the same (or very similar) area or object to show how the two images differ.

After selecting and studying your image, answer the questions below.

4. What is the infrared image you have selected? Describe the image in a short paragraph.

5. How is this image representative of how infrared imaging is used in the field you selected?

6. Why did your team select this particular image?

7. What does the infrared image you selected show that a regular photograph of the same location or object would not show?

8. Why is this important?

9. What do the various colors in your image represent?

10. What can you find out about the technology used to capture the infrared radiation and how it works? What is the wavelength and/or frequency of the captured radiation?

Creating your poster board Your poster board is a visual representation of how infrared imaging is used in the field you selected. Include the image you selected on your poster. Include a description of the image, explaining what it is and why it is important. Include how the image was created, how it should be interpreted and why an infrared image provides an advantage over a regular camera photograph of the same location or object. Include other infrared images and/or diagrams to illustrate the importance of infrared technology to your selected field.

Also, be sure to incorporate the answers to your research questions and cite the sources you used for data and images.

Preparing your presentation Based on your research, prepare a two-minute presentation with your group about how infrared imaging is used in the field you selected. Be sure to incorporate the answers to your research questions.

Tips on creating your presentation:

Use descriptive language. Keep track of the resources and references you are using so you can easily cite them at the end of your project. Create a list of key speaking points, and divvy them up among your group members. Practice your presentation as a group, making sure each group member has a defined and equal role in the presentation.

After the presentations, your teacher will provide instructions for debriefing as a class.

February 1, 2020 Coating Provides Infrared Camouflage

Activity Guide for Students: Seeing in Infrared

Directions for students:

People in many different areas of work use infrared technology to study a variety of phenomena. Infrared radiation is used to monitor volcanic eruptions and temperature trends across Earth. It can be used to detect the presence of drawings underneath paintings, to diagnose diseases and to locate people and animals trapped in fires.

In your small group, you will research how infrared technology is used in a field of your choice. Once you have completed your research by answering the questions that follow, you will create a poster board of your findings and present your research to the rest of the class. Your findings will explain how infrared technology is used in your selected field and why it is important.

Selecting a field that uses infrared images There are many applications of infrared imaging. Follow your teacher’s instructions to identify and select a field of work that uses infrared technology and answer the questions below.

1. What is the field your team chose and why are you interested in this field?

2. Summarize how you think infrared imaging might be used in this field.

3. Why might infrared in this field be an advantage over regular photography?

Selecting your infrared image Using reputable sources (textbooks, peer-reviewed journal articles, websites ending with “.edu,” “.gov” or “.org,” and so on.), find an infrared image that shows an example of how infrared imaging is used in the field you selected. The Science News archive is a good source.

Be sure to select an image that has links to the source, so you can find out what technology was used to capture the image and how it works. The image should include text information about what is shown and, if possible, a scale or key. If the image does not include a key, you should understand how color is used in the image. You may want to select an image that is accompanied by a regular photograph of the same (or very similar) area or object to show how the two images differ.

After selecting and studying your image, answer the questions below.

4. What is the infrared image you have selected? Describe the image in a short paragraph.

5. How is this image representative of how infrared imaging is used in the field you selected?

6. Why did your team select this particular image?

7. What does the infrared image you selected show that a regular photograph of the same location or object would not show?

8. Why is this important?

9. What do the various colors in your image represent?

10. What can you find out about the technology used to capture the infrared radiation and how it works? What is the wavelength and/or frequency of the captured radiation?

Creating your poster board Your poster board is a visual representation of how infrared imaging is used in the field you selected. Include the image you selected on your poster. Include a description of the image, explaining what it is and why it is important. Include how the image was created, how it should be interpreted and why an infrared image provides an advantage over a regular camera photograph of the same location or object. Include other infrared images and/or diagrams to illustrate the importance of infrared technology to your selected field.

Also, be sure to incorporate the answers to your research questions and cite the sources you used for data and images.

Preparing your presentation Based on your research, prepare a two-minute presentation with your group about how infrared imaging is used in the field you selected. Be sure to incorporate the answers to your research questions.

Tips on creating your presentation:

Use descriptive language.

Keep track of the resources and references you are using so you can easily cite them at the end of your project. Create a list of key speaking points, and divvy them up among your group members. Practice your presentation as a group, making sure each group member has a defined and equal role in the presentation.

After the presentations, your teacher will provide instructions for debriefing as a class.

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