The infrared portion of the spectrum has many uses including:
- targeting and tracking by the military
- remote temperature sensing
- short-ranged wireless communication
- weather forecasting
In infrared astronomy telescopes equipped with infrared sensors are used to penetrate dusty regions of space, such as molecular clouds.
Infrared energy causes vibration in a molecule. Infrared spectroscopy exams the absorption and transmission of photons in the infrared energy range, based on their frequency and intensity.
Infrared radiation is often known as heat radiation. Infrared light from the sun accounts for 50% of the heating of the Earth, the rest being caused by visible light. Unlike heat transmitted by thermal conduction or thermal convection, radiation can propagate through a vacuum.