Coating Provides Infrared Camouflage - Science News

COURTESY OF PATRICK RONEY, ALIREZA SHAHSAFI AND MIKHAIL KATS

         February 1, 2020
Coating Provides Infrared Camouflage

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 physics and potential technological applications of a material, discuss the various types of
electromagnetic radiation, 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
spectrum 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 information. 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 temperature.

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 wavelengths of infrared light, the
material does not get brighter as its temperature increases.

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

At the temperatures 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 electromagnetic spectrum 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 energy from one place to another. Classified by
wavelength, the types of electromagnetic radiation are gamma rays, X-rays, ultraviolet, visible light,
infrared, microwaves and radio waves.
Wavelength (and an appropriate unit used to measure it):
The distance between two consecutive crests or toughs of a wave, typically measured in meters (m).
Frequency (and an appropriate unit used to measure it):
The number of crests that pass through a certain point in one second, typically measured in Hertz (Hz) or
waves per second.
The speed of light (and an appropriate unit used to measure it):

The speed at which electromagnetic waves travel in a vacuum. 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 field 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.

3. The first images measure emitted radiation at the 10.7 μm wavelength. Using the key, what do the
colors in these images represent and how would you interpret them?

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.

4. The second images measure emitted radiation for the 6.5 μm wavelength. Using the key, what do the
colors in these images represent and how would you interpret them?

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 universe 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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