Electromagnetic spectrum is lying between the visible and the microwave region is the infrared band spectrum. Like visible light, infrared also has a range of wavelengths. Closer to the visible spectrum band is the 'near infrared' while closer to the microwave spectrum band is the 'far infrared'. The shorter wavelengths are nearly cell-sized and microscopic, while the longer ones have size of pin head.
Longer wavelengths of infrared waves, far infrared, are more energetic. The warmth from the Sun can be experienced as heat energy from the Sun as in warm sidewalk which owes its warmth to infrared radiations. Fast food restaurants often employ infrared in specifically designed lamps and in cooking food. Remote controls that come with the television sets use shorter wavelengths of infrared radiations that are less energetic and not at all hotter.
The warmer the body, the more infrared waves it radiates. Therefore hotter bodies are the major source of the infrared radiations; rather colder bodies like ice cubes also radiate waves in the infrared region. A body unable to radiate in visible region radiate in the infrared region. For instance, heat felt from hot charcoal is the result of the infrared waves radiated from it. At ordinary temperature human body emit infrared waves of 10 microns more consistently. Infrared imaging using specially designed cameras, by giving different brightness, is used to distinguish differences in body temperature which are otherwise undetectable in visible light.
Humans are unable to sense infrared waves while snakes, like rattlesnakes, identify warm-blooded animals with their sensory pits used to image infrared radiations. Apart from animals and human bodies, various heavenly bodies radiate in infrared region like the Earth, the Sun, distant stars, etc. Infrared radiations reflected or radiated from the surface of the Earth are studied with the special sensors like those installed on GOES 6 and Landsat 7 satellites. Infrared coming from the large clouds of dust and gas, stars, and galaxies are explored using Infrared Astronomy Satellite and other satellites.
Longer wavelengths of infrared waves, far infrared, are more energetic. The warmth from the Sun can be experienced as heat energy from the Sun as in warm sidewalk which owes its warmth to infrared radiations. Fast food restaurants often employ infrared in specifically designed lamps and in cooking food. Remote controls that come with the television sets use shorter wavelengths of infrared radiations that are less energetic and not at all hotter.
The warmer the body, the more infrared waves it radiates. Therefore hotter bodies are the major source of the infrared radiations; rather colder bodies like ice cubes also radiate waves in the infrared region. A body unable to radiate in visible region radiate in the infrared region. For instance, heat felt from hot charcoal is the result of the infrared waves radiated from it. At ordinary temperature human body emit infrared waves of 10 microns more consistently. Infrared imaging using specially designed cameras, by giving different brightness, is used to distinguish differences in body temperature which are otherwise undetectable in visible light.
Humans are unable to sense infrared waves while snakes, like rattlesnakes, identify warm-blooded animals with their sensory pits used to image infrared radiations. Apart from animals and human bodies, various heavenly bodies radiate in infrared region like the Earth, the Sun, distant stars, etc. Infrared radiations reflected or radiated from the surface of the Earth are studied with the special sensors like those installed on GOES 6 and Landsat 7 satellites. Infrared coming from the large clouds of dust and gas, stars, and galaxies are explored using Infrared Astronomy Satellite and other satellites.
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