- the part of the invisible spectrum that is contiguous to the red end of the visible spectrum and that comprises electromagnetic radiation of wavelengths from 800 nm to 1 mm.
- noting or pertaining to the infrared or its component rays: infrared radiation.
Origin of infrared
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for infrared
Therefore, it is not possible for any F-35 schedule to include a video data link or infrared pointer at this point.Pentagon Misfires in Stealth Jet Scandal
January 8, 2015
Some pilots consider the infrared marker to be crucial to the close air-support mission to support ground troops.Newest U.S. Stealth Fighter ‘10 Years Behind’ Older Jets
December 26, 2014
Infrared light does not have a color which means it cannot be seen by the human eye.Richard Mosse Photographs War in Technicolor
April 11, 2014
Unlike humans, it can watch for days, even years, watch an entire city, zoom in close, use heat sensors and infrared.Why Drones Make Us Nervous
May 17, 2013
Helicopters equipped with infrared equipment flew over the area.Rogue Ex-Cop Disappears in the Snow
February 8, 2013
Malone flicked on the infrared flashlight he held in his hand.Out Like a Light
Gordon Randall Garrett
The infrared detector gave him no range information, of course.Pushbutton War
Joseph P. Martino
Their vision range is from just within the visible red on into the infrared.Cry from a Far Planet
He pressed the infrared switch and heard the dynamo whine softly.
His eye found the telescope and he pressed the infrared switch.
- the part of the electromagnetic spectrum with a longer wavelength than light but a shorter wavelength than radio waves; radiation with wavelength between 0.8 micrometres and 1 millimetre
- of, relating to, using, or consisting of radiation lying within the infraredinfrared radiation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- Of or relating to the range of invisible radiation wavelengths from about 750 nanometers, just longer than red in the visible spectrum, to 1 millimeter, on the border of the microwave region.
- Generating, using, or sensitive to infrared radiation.
- Infrared light or the infrared part of the spectrum.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- Relating to the invisible part of the electromagnetic spectrum with wavelengths longer than those of visible red light but shorter than those of microwaves. See more at electromagnetic spectrum.
A Closer Look: In 1800 the astronomer Sir William Herschel discovered infrared light while exploring the relationship between heat and light. Herschel used a prism to split a beam of sunlight into a spectrum and then placed a thermometer in each of the bands of light. When he placed the thermometer just outside the red band, where there was no visible color, the temperature rose, as if light were shining on the thermometer. Further experiment showed that this invisible radiation behaved like visible light in many ways; for example, it could be reflected by a mirror. Infrared radiation is simply electromagnetic radiation with a lower frequency than visible light, having longer wavelengths of 0.7 micrometer to 1 millimeter. Ultraviolet radiation, like infrared radiation, lies just outside the visible part of the spectrum, but with higher frequencies; some animals, such as bees, are capable of seeing such radiation. Both infrared and ultraviolet radiation are often referred to as forms of light, though they cannot be seen by human beings. Heat energy is often transferred in the form of infrared radiation, which is given off from an object as a result of molecular collisions within it. Molecules typically have a characteristic infrared absorption spectrum, and infrared spectroscopy is a common technique for identifying the molecular structure of substances. Astronomers similarly analyze the infrared radiation emitted by celestial bodies to determine their temperature and composition.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.