Infrared is a type of invisible light that often carries heat. While our eyes can only see colors from red to violet, infrared light exists just beyond red on the spectrum. We can't see it, but we often feel it as warmth.

When you stand near a campfire, the heat you feel on your face is mostly infrared radiation traveling through the air. The sun bathes Earth in infrared light along with visible light, which is one reason sunshine feels warm. Even your own body constantly gives off infrared light, which is how some animals like pit vipers can “see” warm-blooded prey in total darkness.

Scientists and engineers use infrared technology in fascinating ways. Infrared cameras let firefighters see through smoke to find people trapped in burning buildings. Astronomers use infrared telescopes to study distant stars hidden behind clouds of dust. Television remotes send infrared signals to your TV, flashing patterns of invisible light that tell it to change channels or adjust the volume. Military night-vision goggles can detect infrared light radiating from vehicles, buildings, and people, turning darkness into a visible green-tinted world.

Understanding infrared helps us learn about things our eyes alone can't detect, revealing a hidden world of heat and energy all around us.