Discussion Questions: Infrared Energy

Before Viewing

• Fire is an example of something that gives off both light and heat. The Sun is another such example. Can you think of an object that gives off "invisible" heat - heat you can "feel" but can't "see?"
• Do you give off heat? What's your evidence?
• Think of a time when you saw an x-ray - yours or someone else's. What do you think the x-ray machine was "seeing" when it created the image?

While Viewing

• What kinds of objects give off thermal energy?
• On the electromagnetic spectrum, what is the relationship between infrared energy and visible light?
• What are some of the things scientists study with infrared energy?
• How did Sir William Herschel discover infrared energy?
• Tip: Pause video at 00:35 and rewind to 00:19 to see the visible/infrared comparisons a second time. Pause again at 00:35 and ask students to share their observations about how the images compare.

After Viewing

• In your own words, describe what infrared energy is.
• How is infrared energy similar to energy from other parts of the electromagnetic spectrum – and how is it different?
• Why are satellites able to capture infrared images of the Earth during both daytime and nighttime?
• How do you think an infrared image of a fire in a fireplace would differ from the same scene viewed normally with your eyes?
• Bonus question: What do you think a lizard might look like when viewed through a thermal imaging camera? Hint: Remember that lizards are cold-blooded, so a lizard’s body temperature changes based on its surrounding environment.