Infrared

light · heat · invisible · super useful

Invisible to us. Infrared light has waves that are too long for human eyes to see, even though all warm things around us are constantly giving it off. It sits between visible red light and microwaves on the spectrum of electromagnetic radiation.

Carries heat energy. Almost everything warm emits infrared radiation. That's why thermal cameras can detect heat signatures, and why you feel warmth from a campfire or the sun, even when it's not touching you directly.

Measured in wavelengths. Infrared waves range from about 780 nanometers (just past red light) to 1 millimeter long. Scientists divide it into near infrared, which is closer to visible light, and thermal infrared, which carries more heat energy.

Powers amazing tech. Night vision goggles, thermal cameras, heat sensors, and even TV remotes all use infrared radiation. These tools let us see in darkness and measure temperatures without touching anything.

Wave and particle both. Infrared acts like both a wave (with ups and downs) and like tiny energy packets called photons. This dual nature is true of all light, and it helps scientists understand how radiation works.