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What are shortwave and long wave radiation in regards to heat?
Great question! As strange as it may seem, ALL objects actually radiate energy as waves depending on how hot the are. The higher the temperature of an object, the shorter the waves it will produce. Everyday items like books, tables, or your computer keyboard are at roughly room temperature and radiate in what's called the 'long-wave infrared region.'
In order for your skin to register something as heat, though, it has to have a much shorter wavelength... in what's called the 'shorter-wavelength infrared region.' Even hotter things produce even shorter waves that are actually in the range of visible light instead of infrared! This is why extremely hot objects might look like they're glowing. If you want to see where infrared and visible light lay in the scheme of things, you can look at this picture...
(From The Physics Classroom
(published on 10/22/2007)
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