Infrared

qas: question: Along with industrial and medical, in what applications is infrared radiation used?
answers: text: scientific

question: What technology is used by night-vision devices?
answers: text: active near-infrared illumination

question: What discipline uses infrared telescopes to see through molecular clouds?
answers: text: Infrared astronomy

question: What color shift indicates that space objects date from the early days of the universe?
answers: text: red

question: What devices are used to observe insulated system heat loss?
answers: text: Infrared thermal-imaging cameras

question: What technology allows infrared thermal imaging cameras to observe people or animals without being detected?

question: What technology is used by night vision devices to observe changing blood flow in the skin?

question: What science discipline uses infrared thermal-imaging cameras to penetrate dusty regions of space?

question: Along with industrial and medical, in what applications is infrared astronomy used?

question: What type of radiation is used to detect heat loss in insulated systems?
context: Infrared radiation is used in industrial, scientific, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space, such as molecular clouds; detect objects such as planets, and to view highly red-shifted objects from the early days of the universe. Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect overheating of electrical apparatus.

qas: question: At what wavelength does the human eye become significantly less sensitive to light?
answers: text: 700 nm

question: What sort of light is generated by IR lasers?
answers: text: near-IR

question: Up to what wavelength does the human eye perceive IR LED sources as red?
answers: text: 780 nm

question: Up to what wavelength does the human eye perceive certain intense lights as being dull red in color?
answers: text: 1050 nm

question: What objects are notably bright in near IR?
answers: text: Leaves

question: What is the defined boundary between visible and infrared light?

question: At what wavelength does the human eye perceive red light?

question: What light is generated by an IR-passing photographic filter?

question: What objects are hard to see if all visible light leaks are blocked?

question: What value measures wavelengths as long as 1050?
context: The onset of infrared is defined (according to different standards) at various values typically between 700 nm and 800 nm, but the boundary between visible and infrared light is not precisely defined. The human eye is markedly less sensitive to light above 700 nm wavelength, so longer wavelengths make insignificant contributions to scenes illuminated by common light sources. However, particularly intense near-IR light (e.g., from IR lasers, IR LED sources, or from bright daylight with the visible light removed by colored gels) can be detected up to approximately 780 nm, and will be perceived as red light. Sources providing wavelengths as long as 1050 nm can be seen as a dull red glow in intense sources, causing some difficulty in near-IR illumination of scenes in the dark (usually this practical problem is solved by indirect illumination). Leaves are particularly bright in the near IR, and if all visible light leaks from around an IR-filter are blocked, and the eye is given a moment to adjust to the extremely dim image coming through a visually opaque IR-passing photographic filter, it is possible to see the Wood effect that consists of IR-glowing foliage.

qas: question: What is the term for the property that describes how a surface's thermal emissions deviate from the ideal of a black body?
answers: text: emissivity

question: How will the infrared image of an object with a higher emissivity appear in relation to one with lower emissivity?
answers: text: hotter

question: Along with pyrometers, what devices can receive inaccurate results if emissivity is not set correctly?
answers: text: infrared cameras

question: What property describes how a surfaces thermal emissions give inaccurate results when using infrared cameras and pyrometers?

question: What shows the same image of two objects with differing emissivity?

question: What ideal shows inaccurate results when using infrared cameras?

question: How does pre-set emissivity help infrared cameras give accurate results?

question: How does comparing two differing objects to a black body give you accurate results?
context: The concept of emissivity is important in understanding the infrared emissions of objects. This is a property of a surface that describes how its thermal emissions deviate from the ideal of a black body. To further explain, two objects at the same physical temperature will not show the same infrared image if they have differing emissivity. For example, for any pre-set emissivity value, objects with higher emissivity will appear hotter, and those with a lower emissivity will appear cooler. For that reason, incorrect selection of emissivity will give inaccurate results when using infrared cameras and pyrometers.

qas: question: What is the technique that analyzes the constituent bonds of molecules to identify them?
answers: text: Infrared vibrational spectroscopy

question: What happens to a molecule if an oscillation results in a dipole being changed?
answers: text: it will absorb a photon that has the same frequency

question: What do the vibrational frequencies of molecules usually correspond to?
answers: text: the frequencies of infrared light

question: What is the term for light radiation in the 4000–400 cm−1 spectrum?
answers: text: the mid-infrared

question: What technique can be used to identify organic compounds by analysis of their constituent bonds?

question: A group of chemical bonds in a molecule may have how many modes of oscillation?

question: What do most vibrations correspond to the frequencies of?

question: What are multiple modes of oscillation in a spectrum caused by?

question: What is the amount of absorption a group of atoms will show in cm?
context: Infrared vibrational spectroscopy (see also near-infrared spectroscopy) is a technique that can be used to identify molecules by analysis of their constituent bonds. Each chemical bond in a molecule vibrates at a frequency characteristic of that bond. A group of atoms in a molecule (e.g., CH2) may have multiple modes of oscillation caused by the stretching and bending motions of the group as a whole. If an oscillation leads to a change in dipole in the molecule then it will absorb a photon that has the same frequency. The vibrational frequencies of most molecules correspond to the frequencies of infrared light. Typically, the technique is used to study organic compounds using light radiation from 4000–400 cm−1, the mid-infrared. A spectrum of all the frequencies of absorption in a sample is recorded. This can be used to gain information about the sample composition in terms of chemical groups present and also its purity (for example, a wet sample will show a broad O-H absorption around 3200 cm−1).

qas: question: What is used in infrared photography to capture the near-infrared spectrum?
answers: text: infrared filters

question: What devices are often equipped with infrared blockers?
answers: text: Digital cameras

question: What is the technique that involves imaging with terahertz radiation?
answers: text: 'T-ray' imaging

question: What is another name for terahertz radiation?
answers: text: far-infrared

question: What is a notable recent development in T-ray imaging?
answers: text: terahertz time-domain spectroscopy

question: What does T-ray imaging use to capture the near-infrared spectrum?

question: What is a recent development in infrared photography?

question: What is another name for IR bright areas?

question: What device uses far-infrared or terahertz radiation?

question: How do infrared blockers wash out an image?
context: In infrared photography, infrared filters are used to capture the near-infrared spectrum. Digital cameras often use infrared blockers. Cheaper digital cameras and camera phones have less effective filters and can "see" intense near-infrared, appearing as a bright purple-white color. This is especially pronounced when taking pictures of subjects near IR-bright areas (such as near a lamp), where the resulting infrared interference can wash out the image. There is also a technique called 'T-ray' imaging, which is imaging using far-infrared or terahertz radiation. Lack of bright sources can make terahertz photography more challenging than most other infrared imaging techniques. Recently T-ray imaging has been of considerable interest due to a number of new developments such as terahertz time-domain spectroscopy.

qas: question: What technique is used in art to examine underlying layers of a painting without damaging it?
answers: text: Infrared reflectography

question: What shows up particularly well in reflectograms?
answers: text: carbon black

question: What is the term for differences in the painting and underdrawing made by the original artist?
answers: text: pentimenti

question: What painting technique is used to reveal working practices?

question: What is visible in alterations of paintings?

question: What is it called when visible layers differ from the reflectogram?

question: What is useful to show if a painting is original or part of a reflectogram?

question: With carbon black what is the painting more likely to be?
context: Infrared reflectography (fr; it; es), as called by art conservators, can be applied to paintings to reveal underlying layers in a completely non-destructive manner, in particular the underdrawing or outline drawn by the artist as a guide. This often reveals the artist's use of carbon black, which shows up well in reflectograms, as long as it has not also been used in the ground underlying the whole painting. Art conservators are looking to see whether the visible layers of paint differ from the underdrawing or layers in between – such alterations are called pentimenti when made by the original artist. This is very useful information in deciding whether a painting is the prime version by the original artist or a copy, and whether it has been altered by over-enthusiastic restoration work. In general, the more pentimenti the more likely a painting is to be the prime version. It also gives useful insights into working practices.

qas: question: Who discovered infrared radiation?
answers: text: William Herschel

question: In what year did Herschel publish his work on infrared radiation?
answers: text: 1800

question: To whom did Herschel present his work on infrared radiation?
answers: text: the Royal Society of London

question: What device did Herschel use to discover the infrared?
answers: text: a prism

question: What did Herschel call the infrared spectrum?
answers: text: Calorific Rays

question: Who discovered spectrum radiation?

question: When did the term Calorific Rays start to be used?

question: What did Herschel use to detect light from the sun?

question: What did Herschel refract from Calorific Rays?

question: What society did Herschel present his work on the red spectrum?
context: The discovery of infrared radiation is ascribed to William Herschel, the astronomer, in the early 19th century. Herschel published his results in 1800 before the Royal Society of London. Herschel used a prism to refract light from the sun and detected the infrared, beyond the red part of the spectrum, through an increase in the temperature recorded on a thermometer. He was surprised at the result and called them "Calorific Rays". The term 'Infrared' did not appear until late in the 19th century.

qas: question: What is a commonly used term for infrared radiation?
answers: text: heat radiation

question: What percentage of the Earth's heat is derived from the Sun's infrared light?
answers: text: 49%

question: What is the common range of emitted radiation of room temperature objects, in micrometers? 
answers: text: 8 to 25

question: Other than infrared light, what type of light is responsible for heating the Earth?
answers: text: visible

question: What radiation is responsible for 49% of the heating of the Earth?

question: Other than infrared light, what type of light is responsible for emitting visible radiation?

question: What type of light or laser will emit radiation concentrated mostly in the 8 to 25 um band?

question: What type of waves will char paper?
context: Infrared radiation is popularly known as "heat radiation"[citation needed], but light and electromagnetic waves of any frequency will heat surfaces that absorb them. Infrared light from the Sun accounts for 49% of the heating of Earth, with the rest being caused by visible light that is absorbed then re-radiated at longer wavelengths. Visible light or ultraviolet-emitting lasers can char paper and incandescently hot objects emit visible radiation. Objects at room temperature will emit radiation concentrated mostly in the 8 to 25 µm band, but this is not distinct from the emission of visible light by incandescent objects and ultraviolet by even hotter objects (see black body and Wien's displacement law).

qas: question: What is another term for infrared homing?
answers: text: Infrared tracking

question: What devices make use of infrared homing?
answers: text: Missiles

question: What is a common name for missiles that make use of infrared seeking?
answers: text: heat-seekers

question: Along with aircraft and people, what objects notably create and retain heat?
answers: text: vehicle engines

question: What does IR stand for?
answers: text: infrared

question: What is another term for heat seekers?

question: Besides vehicle engines and people what other objects create and retain heat?

question: What term means to generate heat and is especially visible in infrared wavelengths of light?

question: What is the term that uses the infrared spectrum that is radiated by hot bodies?

question: What term describes the spectrum of light that is part of the visible spectrum?
context: Infrared tracking, also known as infrared homing, refers to a passive missile guidance system, which uses the emission from a target of electromagnetic radiation in the infrared part of the spectrum to track it. Missiles that use infrared seeking are often referred to as "heat-seekers", since infrared (IR) is just below the visible spectrum of light in frequency and is radiated strongly by hot bodies. Many objects such as people, vehicle engines, and aircraft generate and retain heat, and as such, are especially visible in the infrared wavelengths of light compared to objects in the background.

qas: question: Along with Cirrus, what types of clouds are cold and high?
answers: text: Cumulonimbus

question: What color do Cirrus clouds appear in infrared?
answers: text: white

question: Along with Stratus, what clouds are lower and warmer?
answers: text: Stratocumulus

question: What color are Strarus clouds in infrared?
answers: text: grey

question: What is the range of the near-infrared channel in micrometers?
answers: text: 1.58–1.64

question: Besides cumulonimbus, what types of clouds are lower and warmer?

question: What ice clouds show up grey in infrared?

question: What land surface can be a similar temperature to the surrounding land?

question: What color are lower intermediate clouds on infrared?

question: What difference allows high clouds to be distinguished?
context: High, cold ice clouds such as Cirrus or Cumulonimbus show up bright white, lower warmer clouds such as Stratus or Stratocumulus show up as grey with intermediate clouds shaded accordingly. Hot land surfaces will show up as dark-grey or black. One disadvantage of infrared imagery is that low cloud such as stratus or fog can be a similar temperature to the surrounding land or sea surface and does not show up. However, using the difference in brightness of the IR4 channel (10.3–11.5 µm) and the near-infrared channel (1.58–1.64 µm), low cloud can be distinguished, producing a fog satellite picture. The main advantage of infrared is that images can be produced at night, allowing a continuous sequence of weather to be studied.

qas: question: What limits the sensitivity of infrared telescopes on Earth?
answers: text: water vapor in the atmosphere

question: To somewhat avoid the water vapor in the atmosphere, where can an observatory be sited?
answers: text: at a high altitude

question: Along with aircraft, what object can be used to carry a telescope aloft?
answers: text: balloon

question: What sorts of telescopes completely avoid water vapor in Earth's atmosphere?
answers: text: Space telescopes

question: What limits the sensitivity of high altitude observatories?

question: What is the ideal location for atmospheric windows?

question: What kind of telescopes avoid absorbing infrared radiation?

question: Where can you place an observatory to avoid the atmospheric window?

question: What absorbs infrared radiation from space away from high altitude?
context: The sensitivity of Earth-based infrared telescopes is significantly limited by water vapor in the atmosphere, which absorbs a portion of the infrared radiation arriving from space outside of selected atmospheric windows. This limitation can be partially alleviated by placing the telescope observatory at a high altitude, or by carrying the telescope aloft with a balloon or an aircraft. Space telescopes do not suffer from this handicap, and so outer space is considered the ideal location for infrared astronomy.

qas: question: What is the nearest wavelength to the radiation that a human eye can see?
answers: text: Near-infrared

question: Along with the emission peaks and vs. bands mechanisms, what other physical mechanism is used to define near-infrared?
answers: text: water absorption

question: In micrometers, when do common silicon detectors cease to be sensitive?
answers: text: 1,050

question: What is the lowest level of sensitivity, in micrometers, for InGaAs?
answers: text: 950

question: What is the lowest international standard in micrometers for InGaAs?

question: What is the nearest emission peak visible to the human eye?

question: Along with the emission peaks and vs. bands mechanisms, what other physical mechanism is used to define common silicon detectors?

question: What InGaAs is progressively further from the visible spectrum for the human eye?

question: At what measurement do different physical mechanisms cease to be sensitive?
context: Near-infrared is the region closest in wavelength to the radiation detectable by the human eye, mid- and far-infrared are progressively further from the visible spectrum. Other definitions follow different physical mechanisms (emission peaks, vs. bands, water absorption) and the newest follow technical reasons (the common silicon detectors are sensitive to about 1,050 nm, while InGaAs's sensitivity starts around 950 nm and ends between 1,700 and 2,600 nm, depending on the specific configuration). Unfortunately, international standards for these specifications are not currently available.

qas: question: What is the term for transit energy flowing as a result of differences in temperature?
answers: text: Heat

question: What type of heat transmission can propagate through a vacuum?
answers: text: thermal radiation

question: What object emits thermal radiation in the X-ray spectrum?
answers: text: the solar corona

question: The visible, ultraviolet and X-ray spectra are all above what spectrum?
answers: text: infrared

question: How does heat propagate through a vaccuum?

question: What object emits heat in the x-ray spectrum?

question: How is heat associated with emission from an object?

question: What spectra is heat extended into?

question: What is the association of heat with thermal radiation?
context: Heat is energy in transit that flows due to temperature difference. Unlike heat transmitted by thermal conduction or thermal convection, thermal radiation can propagate through a vacuum. Thermal radiation is characterized by a particular spectrum of many wavelengths that is associated with emission from an object, due to the vibration of its molecules at a given temperature. Thermal radiation can be emitted from objects at any wavelength, and at very high temperatures such radiations are associated with spectra far above the infrared, extending into visible, ultraviolet, and even X-ray regions (i.e., the solar corona). Thus, the popular association of infrared radiation with thermal radiation is only a coincidence based on typical (comparatively low) temperatures often found near the surface of planet Earth.

qas: question: What is the range of the electromagnetic spectrum in micrometers?
answers: text: 0.9–14

question: In nanometers, what is the electromagnetic spectrum's range?
answers: text: 900–14,000

question: What law states that infrared radiation is emitted by objects based on temperature?
answers: text: the black body radiation law

question: What happens to the amount of radiation an object emits as temperature increases?
answers: text: increases

question: What type of cameras see infrared radiation?
answers: text: Thermographic

question: What camera detects temperature in the infrared range?

question: What law states that infrared radiation is emitted by objects based on environment?

question: When an object has visible illumination, what happens to the amount of radiation an object emits?

question: What is the range of the black body radiation law?

question: What is the nanometer range that allows you to see temperature variations?
context: Thermographic cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 900–14,000 nanometers or 0.9–14 μm) and produce images of that radiation. Since infrared radiation is emitted by all objects based on their temperatures, according to the black body radiation law, thermography makes it possible to "see" one's environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature, therefore thermography allows one to see variations in temperature (hence the name).

qas: question: What irradiates clouds of gas in the galaxy and makes them glow?
answers: text: imbedded stars

question: What can be detected via infrared prior to their emitting visible light?
answers: text: protostars

question: What objects emit less of their energy as infrared light versus visible light?
answers: text: Stars

question: What glows with heat and shows visible light?

question: What can be used to detect protostars when they are cool?

question: What spectrum benefits stars?

question: What heats clouds of gas and makes them readily detected?

question: What do stars emit a smaller portion of in our galaxy?
context: The infrared portion of the spectrum has several useful benefits for astronomers. Cold, dark molecular clouds of gas and dust in our galaxy will glow with radiated heat as they are irradiated by imbedded stars. Infrared can also be used to detect protostars before they begin to emit visible light. Stars emit a smaller portion of their energy in the infrared spectrum, so nearby cool objects such as planets can be more readily detected. (In the visible light spectrum, the glare from the star will drown out the reflected light from a planet.)

qas: question: What sort of equipment uses the infrared spectrum in the absence of sufficient visible light?
answers: text: night vision

question: What do night vision devices convert ambient light photons into?
answers: text: electrons

question: Along with a chemical process, what type of process is used by night vision devices to convert infrared into visible light?
answers: text: electrical

question: What equipment uses the infrared spectrum with visible light?

question: What do night vision devices convert electrons into?

question: By what process do night vision devices convert infrared into photons?

question: What process uses a chemical source to augment ambient light?

question: What does a visible light source increase for a night vision device?
context: Infrared is used in night vision equipment when there is insufficient visible light to see. Night vision devices operate through a process involving the conversion of ambient light photons into electrons that are then amplified by a chemical and electrical process and then converted back into visible light. Infrared light sources can be used to augment the available ambient light for conversion by night vision devices, increasing in-the-dark visibility without actually using a visible light source.

qas: question: What is the IrDA?
answers: text: the Infrared Data Association

question: What does the acronym LEDs stand for?
answers: text: light-emitting diodes

question: What is a term for when something is switched on and off?
answers: text: modulated

question: What device is used to transform infrared radiation into an electric current?
answers: text: silicon photodiode

question: Why does infrared not cause trouble for devices in adjacent rooms?
answers: text: IR does not penetrate walls

question: What term means filtering out slowly to change infrared radiation from ambient light?

question: What device changes infrared radiation to standards published by the Ir DA?

question: What devices use IR data transmission in short range communication to command appliances?

question: Name the devices that use IrDA to emit infrared radiation that is focused by a plastic lens into a narrow beam. 

question: What infrared remote control protocols are used in areas of high population density?
context: IR data transmission is also employed in short-range communication among computer peripherals and personal digital assistants. These devices usually conform to standards published by IrDA, the Infrared Data Association. Remote controls and IrDA devices use infrared light-emitting diodes (LEDs) to emit infrared radiation that is focused by a plastic lens into a narrow beam. The beam is modulated, i.e. switched on and off, to encode the data. The receiver uses a silicon photodiode to convert the infrared radiation to an electric current. It responds only to the rapidly pulsing signal created by the transmitter, and filters out slowly changing infrared radiation from ambient light. Infrared communications are useful for indoor use in areas of high population density. IR does not penetrate walls and so does not interfere with other devices in adjoining rooms. Infrared is the most common way for remote controls to command appliances. Infrared remote control protocols like RC-5, SIRC, are used to communicate with infrared.

qas: question: What letter represents the index of refraction?
answers: text: n

question: What letter represents the extinction Coefficient?
answers: text: k

question: What equations are used to figure out the index of refraction and extinction Coefficient?
answers: text: Forouhi-Bloomer dispersion

question: Along with critical dimension and depth, what can the infrared light reflectance be used to determine in regard to high aspect ratio trench structures?
answers: text: sidewall angle

question: What reflectance is measured from a semiconductor wafer's surface to determine the index of refraction?
answers: text: light

question: What industry can use infrared light to characterize the extinction Coefficient?

question: What reflectance is measured from the surface of a critical dimension?

question: What letter represents trench structures?

question: Along with critical dimension and depth, what can infrared light reflectance be used to determine in regard to index of refraction?
context: In the semiconductor industry, infrared light can be used to characterize materials such as thin films and periodic trench structures. By measuring the reflectance of light from the surface of a semiconductor wafer, the index of refraction (n) and the extinction Coefficient (k) can be determined via the Forouhi-Bloomer dispersion equations. The reflectance from the infrared light can also be used to determine the critical dimension, depth, and sidewall angle of high aspect ratio trench structures.

qas: question: What is the name of the technique used in scanners to minimize the effects of dust and scratches?
answers: text: Infrared cleaning

question: Along with red and blue, what is the third visible color channel?
answers: text: green

question: Along with replacement via inpainting, what procedure is used in infrared cleaning to remove the effect of scratches and dust?
answers: text: scaling

question: Along with the visible light channels, what channel is used to locate scratches and dust in scanners?
answers: text: infrared

question: What cleaning technique is used to find position and resolution?

question: What can be corrected by scanning or scaling?

question: What color channels are used to detect inpainting?

question: What does infrared cleaning do to detect scaling?

question: What removes the effects of an additional infrared channel on the scanner? 
context: Infrared cleaning is a technique used by some Motion picture film scanner, film scanners and flatbed scanners to reduce or remove the effect of dust and scratches upon the finished scan. It works by collecting an additional infrared channel from the scan at the same position and resolution as the three visible color channels (red, green, and blue). The infrared channel, in combination with the other channels, is used to detect the location of scratches and dust. Once located, those defects can be corrected by scaling or replaced by inpainting.

qas: question: Along with the surface of the Earth, what objects absorb radiation from the sun?
answers: text: clouds

question: After Earth surface's absorbs radiation, in what spectrum is much of it re-emitted?
answers: text: infrared

question: Along with water vapor, what atmospheric substance primarily absorbs the infrared emitted by the Earth?
answers: text: cloud droplets

question: What notable warming effect does the presence of infrared absorbers contribute to?
answers: text: greenhouse

question: What does the greenhouse effect absorb from the sun?

question: After Earth absorbs methane, in what spectrum is it re-emitted?

question: What substances absorb the sulfur hexafluoride emitted by the Earth?

question: What keeps the atmosphere and surface re-radiated?

question: What substances emit water vapor back to the atmosphere?
context: Earth's surface and the clouds absorb visible and invisible radiation from the sun and re-emit much of the energy as infrared back to atmosphere. Certain substances in the atmosphere, chiefly cloud droplets and water vapor, but also carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, and chlorofluorocarbons, absorb this infrared, and re-radiate it in all directions including back to Earth. Thus, the greenhouse effect keeps the atmosphere and surface much warmer than if the infrared absorbers were absent from the atmosphere.