Infrared radiation is felt as heat and can travel through a vacuum. The sun’s infrared heat warms the Earth, and artificial infrared heat is used in industry and therapy. Near infrared is used for data transmission, while medium and far infrared waves are felt as heat.
Infrared refers to the wavelengths of the electromagnetic spectrum that lie between visible light and microwaves. Infrared radiation is perceived by us as heat, even if we cannot see it. The origin of infrared heat is at the atomic level, where the heat generated by the movement of subatomic particles is transformed into electromagnetic radiation in the infrared range. Infrared heat should be distinguished from thermal convection and thermal conduction because it can travel through a vacuum.
To look at how infrared heat works, heating and cooling the earth is probably the most useful example. In addition to driving all weather events and patterns, as well as ocean currents, the sun’s infrared heat is what warms the Earth during the day, and it’s what the land gives off at night after dark. Interestingly, while the sun gives off a huge amount of infrared heat, only about half of the heat we feel on the ground comes from the sun’s direct infrared radiation. The other half comes from visible light energy that is absorbed by objects on earth and then emitted as infrared heat.
Artificial infrared heat is used in a variety of applications. In industrial settings, the heating and welding of plastics is accomplished by infrared heaters, as are the curing of some coatings and some steps in glass manufacturing. Many of us have seen infrared heat lamps in restaurants, which are used to keep food warm before it’s served. These are specially designed bulbs that are made to emit as much infrared energy as possible, with less emphasis on producing light.
Infrared heat can also be produced deliberately in such a way that it has a therapeutic effect. Far infrared radiation is sometimes used to provide pain relief for arthritis patients and others suffering from chronic pain. It is also used to defrost aircraft wings and in infrared saunas.
Not all infrared wavelengths are perceived by us as heat. The light that is just beyond the red side of the visible spectrum isn’t hot at all, and this is the kind of infrared light used by remote controls and some computing devices to transmit data. This part of the infrared range is called the near infrared because it is close to the visible spectrum. The medium and far infrared waves are what we notice as caloric heat.
Protect your devices with Threat Protection by NordVPN
