sentence-transformers/squad huggingface dataset:
Passage: Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

Question: What is the basic SI unit of measurement?

Question: What is the SI unit for lumiance?

Question: What is the CGS unit of lumiance?

Question: What is the amount of useful light emitted from a luminous flux measured in?
Passage: The SI unit of illuminance and luminous emittance, being the luminous power per area, is measured in Lux. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface. It is analogous to the radiometric unit watts per square metre, but with the power at each wavelength weighted according to the luminosity function, a standardized model of human visual brightness perception. In English, "lux" is used in both singular and plural.

Question: What is a standardized model of human visual brightness?

Question: What is the SI unit of illuminace and luminous emittance?
Passage: Several measurement methods have been developed to control glare resulting from indoor lighting design. The Unified Glare Rating (UGR), the Visual Comfort Probability, and the Daylight Glare Index are some of the most well-known methods of measurement. In addition to these new methods, four main factors influence the degree of discomfort glare; the luminance of the glare source, the solid angle of the glare source, the background luminance, and the position of the glare source in the field of view must all be taken into account.

Question: What does UGR stand for?
Passage: To define light source color properties, the lighting industry predominantly relies on two metrics, correlated color temperature (CCT), commonly used as an indication of the apparent "warmth" or "coolness" of the light emitted by a source, and color rendering index (CRI), an indication of the light source’s ability to make objects appear natural.

Question: What does CCT stand for?

Question: What does CRI stand for?

Question: What metric indicates a lights ability to make object appear natural?

Question: What metric indicates "warmth" or "coolness"?
Passage: For example, in order to meet the expectations for good color rendering in retail applications, research suggests using the well-established CRI along with another metric called gamut area index (GAI). GAI represents the relative separation of object colors illuminated by a light source; the greater the GAI, the greater the apparent saturation or vividness of the object colors. As a result, light sources which balance both CRI and GAI are generally preferred over ones that have only high CRI or only high GAI.

Question: What does GAI stand for?

Question: The relative separating of object colors illuminated by a light source is known as?

Question: Would a lower GAI mean higher apparent saturation or vividness of object colors?
Passage: Typical measurements of light have used a Dosimeter. Dosimeters measure an individual's or an object's exposure to something in the environment, such as light dosimeters and ultraviolet dosimeters.

Question: What is typically used to measure light?
Passage: In order to specifically measure the amount of light entering the eye, personal circadian light meter called the Daysimeter has been developed. This is the first device created to accurately measure and characterize light (intensity, spectrum, timing, and duration) entering the eye that affects the human body's clock.

Question: What measures the amount of light entering the eye?

Question: A Daysimeter what type of personal meter?
Passage: The small, head-mounted device measures an individual's daily rest and activity patterns, as well as exposure to short-wavelength light that stimulates the circadian system. The device measures activity and light together at regular time intervals and electronically stores and logs its operating temperature. The Daysimeter can gather data for up to 30 days for analysis.

Question: How many days can the Daysimeter gather for analysis?

Question: What type of light stimulates the circadian system?
Passage: Specification of illumination requirements is the basic concept of deciding how much illumination is required for a given task. Clearly, much less light is required to illuminate a hallway compared to that needed for a word processing work station. Generally speaking, the energy expended is proportional to the design illumination level. For example, a lighting level of 400 lux might be chosen for a work environment involving meeting rooms and conferences, whereas a level of 80 lux could be selected for building hallways. If the hallway standard simply emulates the conference room needs, then much more energy will be consumed than is needed. Unfortunately, most of the lighting standards even today have been specified by industrial groups who manufacture and sell lighting, so that a historical commercial bias exists in designing most building lighting, especially for office and industrial settings.

Question: What is a basic concept of deciding how much illumination is required for a given task?
Passage: Lighting control systems reduce energy usage and cost by helping to provide light only when and where it is needed. Lighting control systems typically incorporate the use of time schedules, occupancy control, and photocell control (i.e.daylight harvesting). Some systems also support demand response and will automatically dim or turn off lights to take advantage of utility incentives. Lighting control systems are sometimes incorporated into larger building automation systems.

Question: What can help reduce energy and usage cost by providing light only when or where it is needed?
Passage: Many newer control systems are using wireless mesh open standards (such as ZigBee), which provides benefits including easier installation (no need to run control wires) and interoperability with other standards-based building control systems (e.g. security).

Question: What type of standard do newer control systems use?

Question: What is the name of one type of control system used?

Question: Does a wireless mesh open standard make installation harder?
Passage: Occupancy sensors to allow operation for whenever someone is within the area being scanned can control lighting. When motion can no longer be detected, the lights shut off. Passive infrared sensors react to changes in heat, such as the pattern created by a moving person. The control must have an unobstructed view of the building area being scanned. Doors, partitions, stairways, etc. will block motion detection and reduce its effectiveness. The best applications for passive infrared occupancy sensors are open spaces with a clear view of the area being scanned. Ultrasonic sensors transmit sound above the range of human hearing and monitor the time it takes for the sound waves to return. A break in the pattern caused by any motion in the area triggers the control. Ultrasonic sensors can see around obstructions and are best for areas with cabinets and shelving, restrooms, and open areas requiring 360-degree coverage. Some occupancy sensors utilize both passive infrared and ultrasonic technology, but are usually more expensive. They can be used to control one lamp, one fixture or many fixtures.

Question: What sensor controls light with motion sensors?

Question: What does a passive infrared sensor react to?

Question: What type of sensor transmits sound above the range of human hearing?

Question: Would you want to use passive infrared sensor in a area requiring 360-degree coverage?
Passage: Daylighting is the oldest method of interior lighting. Daylighting is simply designing a space to use as much natural light as possible. This decreases energy consumption and costs, and requires less heating and cooling from the building. Daylighting has also been proven to have positive effects on patients in hospitals as well as work and school performance. Due to a lack of information that indicate the likely energy savings, daylighting schemes are not yet popular among most buildings.

Question: What is the oldest method of interior lighting?

Question: Daylighting has been proven to have negative effects on people?
Passage: In recent years light emitting diodes (LEDs) are becoming increasingly efficient leading to an extraordinary increase in the use of solid state lighting. In many situations, controlling the light emission of LEDs may be done most effectively by using the principles of nonimaging optics.

Question: What is a form of solid state lighting?

Question: What is the best way to control light emissions of LEDs?
Passage: Beyond the energy factors being considered, it is important not to over-design illumination, lest adverse health effects such as headache frequency, stress, and increased blood pressure be induced by the higher lighting levels. In addition, glare or excess light can decrease worker efficiency.

Question: What can cause health effects such headache frequency?
Passage: Analysis of lighting quality particularly emphasizes use of natural lighting, but also considers spectral content if artificial light is to be used. Not only will greater reliance on natural light reduce energy consumption, but will favorably impact human health and performance. New studies have shown that the performance of students is influenced by the time and duration of daylight in their regular schedules. Designing school facilities to incorporate the right types of light at the right time of day for the right duration may improve student performance and well-being. Similarly, designing lighting systems that maximize the right amount of light at the appropriate time of day for the elderly may help relieve symptoms of Alzheimer's Disease. The human circadian system is entrained to a 24-hour light-dark pattern that mimics the earth’s natural light/dark pattern. When those patterns are disrupted, they disrupt the natural circadian cycle. Circadian disruption may lead to numerous health problems including breast cancer, seasonal affective disorder, delayed sleep phase syndrome, and other ailments.

Question: Maximizing the right amount of light at the appropriate time for elderly may help systems of what?

Question: The human circadian system is entrained to how many hours light-dark pattern?

Question: What happens to the natural carcidan cycle when light-dark patterns are disrupted?
Passage: A study conducted in 1972 and 1981, documented by Robert Ulrich, surveyed 23 surgical patients assigned to rooms looking out on a natural scene. The study concluded that patients assigned to rooms with windows allowing lots of natural light had shorter postoperative hospital stays, received fewer negative evaluative comments in nurses’ notes, and took fewer potent analegesics than 23 matched patients in similar rooms with windows facing a brick wall. This study suggests that due to the nature of the scenery and daylight exposure was indeed healthier for patients as opposed to those exposed to little light from the brick wall. In addition to increased work performance, proper usage of windows and daylighting crosses the boundaries between pure aesthetics and overall health.

Question: Who documented 23 surgical patients assigned rooms looking out on a natural scene?

Question: Did the patients with natural scenes have longer postoperative hospital stays?

Question: Did patients that have natural scenes require more potent analgesics?
Passage: Alison Jing Xu, assistant professor of management at the University of Toronto Scarborough and Aparna Labroo of Northwestern University conducted a series of studies analyzing the correlation between lighting and human emotion. The researchers asked participants to rate a number of things such as: the spiciness of chicken-wing sauce, the aggressiveness of a fictional character, how attractive someone was, their feelings about specific words, and the taste of two juices–all under different lighting conditions. In their study, they found that both positive and negative human emotions are felt more intensely in bright light. Professor Xu stated, "we found that on sunny days depression-prone people actually become more depressed." They also found that dim light makes people make more rational decisions and settle negotiations easier. In the dark, emotions are slightly suppressed. However, emotions are intensified in the bright light.

Question: What University was Alision Jing Xu the assistant professor of management at?

Question: What Univerity was Aparna Labroo associated with?
Passage: In 1849, Dr. Abraham Gesner, a Canadian geologist, devised a method where kerosene could be distilled from petroleum. Earlier coal-gas methods had been used for lighting since the 1820s, but they were expensive. Gesner's kerosene was cheap, easy to produce, could be burned in existing lamps, and did not produce an offensive odor as did most whale oil. It could be stored indefinitely, unlike whale oil, which would eventually spoil. The American petroleum boom began in the 1850s. By the end of the decade there were 30 kerosene plants operating in the United States. The cheaper, more efficient fuel began to drive whale oil out of the market. John D. Rockefeller was most responsible for the commercial success of kerosene. He set up a network of kerosene distilleries which would later become Standard Oil, thus completely abolishing the need for whale-oil lamps. These types of lamps may catch fire or emit carbon-monoxide and sometimes are odorous making them problematic for asthmatic people.

Question: What devised a method where kerosene could be distilled from petroleum?

Question: What year was it discovered that petroleum could be distilled into kerosene?

Question: What method of lighting have been used since 1820s?
Passage: Compact fluorescent lamps (aka 'CFLs') use less power to supply the same amount of light as an incandescent lamp, however they contain mercury which is a dispose hazard. Due to the ability to reduce electric consumption, many organizations have undertaken measures to encourage the adoption of CFLs. Some electric utilities and local governments have subsidized CFLs or provided them free to customers as a means of reducing electric demand. For a given light output, CFLs use between one fifth and one quarter of the power of an equivalent incandescent lamp. One of the simplest and quickest ways for a household or business to become more energy efficient is to adopt CFLs as the main lamp source, as suggested by the Alliance for Climate Protection. Unlike incandescent lamps CFL's need a little time to 'warm up' and reach full brightness. Care should be taken when selecting CFL's because not all of them are suitable for dimming.

Question: What does CFL stand for?

Question: Are all CFLs suitable for dimming?
Passage: LED lamps have been advocated as the newest and best environmental lighting method. According to the Energy Saving Trust, LED lamps use only 10% power compared to a standard incandescent bulb, where compact fluorescent lamps use 20% and energy saving halogen lamps 70%. The lifetime is also much longer — up to 50,000 hours. A downside is still the initial cost, which is higher than that of compact fluorescent lamps.

Question: How much more power does a standard incandescent bulb use compared to LED?

Question: What is the average lifetime of a CFL?

Question: What is the average lifetime of a CFL?

Question: How much power does a halogen lamp save compared to a standard blub?
Passage: Light pollution is a growing problem in reaction to excess light being given off by numerous signs, houses, and buildings. Polluting light is often wasted light involving unnecessary energy costs and carbon dioxide emissions. Light pollution is described as artificial light that is excessive or intrudes where it is not wanted. Well-designed lighting sends light only where it is needed without scattering it elsewhere. Poorly designed lighting can also compromise safety. For example, glare creates safety issues around buildings by causing very sharp shadows, temporarily blinding passersby making them vulnerable to would-be assailants.

Question: What is known as artificial light that is excessive or intrusive?

Question: What causes sharp shadows around buildings?
Passage: From a military standpoint, lighting is a critical part of the battlefield conditions. Shadows are good places to hide, while bright areas are more exposed. It is often beneficial to fight with the Sun or other light source behind you, giving your enemy disturbing visual glare and partially hiding your own movements in backlight. If natural light is not present searchlights and flares can be used. However the use of light may disclose your own hidden position and modern warfare have seen increased use of night vision through the use of infrared cameras and image intensifiers.

Question: In a battlefield does not have natural light what could you use instead?

Question: The use of what may disclose your own hidden position on a battlefield?

Question: Modern warfare has seen the increased use of what?
Passage: Flares can also be used by the military to mark positions, usually for targeting, but laser-guided and GPS weapons have eliminated this need for the most part.

Question: What can be used by military for targeting?

Question: What has eliminated the need for flares on a battlefield?
Passage: The International Commission on Illumination (CIE) is an international authority and standard defining organization on color and lighting. Publishing widely used standard metrics such as various CIE color spaces and the color rendering index.

Question: What does the CIE stand for?
Passage: The Illuminating Engineering Society of North America (IESNA), in conjunction with organizations like ANSI and ASHRAE, publishes guidelines, standards, and handbooks that allow categorization of the illumination needs of different built environments. Manufacturers of lighting equipment publish photometric data for their products, which defines the distribution of light released by a specific luminaire. This data is typically expressed in standardized form defined by the IESNA.

Question: What does the IESNA stand for?

Question: Who else publishes along with IESNA?

Question: What defines photo metric data?
Passage: The International Association of Lighting Designers (IALD) is an organization which focuses on the advancement of lighting design education and the recognition of independent professional lighting designers. Those fully independent designers who meet the requirements for professional membership in the association typically append the abbreviation IALD to their name.

Question: What does IALD stand for?
Passage: The Professional Lighting Designers Association (PLDA), formerly known as ELDA is an organisation focusing on the promotion of the profession of Architectural Lighting Design. They publish a monthly newsletter and organise different events throughout the world.

Question: What does PLDA stand for?

Question: What was the PLDA formerly known as?
Passage: The National Council on Qualifications for the Lighting Professions (NCQLP) offers the Lighting Certification Examination which tests rudimentary lighting design principles. Individuals who pass this exam become ‘Lighting Certified’ and may append the abbreviation LC to their name. This certification process is one of three national (U.S.) examinations (the others are CLEP and CLMC) in the lighting industry and is open not only to designers, but to lighting equipment manufacturers, electric utility employees, etc.

Question: Who offers the Lighting Certification Examination?

Question: What does NCQLP stand for?

Question: Which abbreviation can you append to your name after becoming Lighting Certified?

Question: What other national examinations are available?
Passage: The Professional Lighting And Sound Association (PLASA) is a UK-based trade organisation representing the 500+ individual and corporate members drawn from the technical services sector. Its members include manufacturers and distributors of stage and entertainment lighting, sound, rigging and similar products and services, and affiliated professionals in the area. They lobby for and represent the interests of the industry at various levels, interacting with government and regulating bodies and presenting the case for the entertainment industry. Example subjects of this representation include the ongoing review of radio frequencies (which may or may not affect the radio bands in which wireless microphones and other devices use) and engaging with the issues surrounding the introduction of the RoHS (Restriction of Hazardous Substances Directive) regulations.

Question: What does PLASA stand for?

Question: Where is PLASA based?

Question: How many individuals does PLASA represent?

Question: What does RoHS stand for?
Passage: Separation of powers is a political doctrine originating in the writings of Montesquieu in The Spirit of the Laws where he urged for a constitutional government with three separate branches of government. Each of the three branches would have defined abilities to check the powers of the other branches. This idea was called separation of powers. This philosophy heavily influenced the writing of the United States Constitution, according to which the Legislative, Executive, and Judicial branches of the United States government are kept distinct in order to prevent abuse of power. This United States form of separation of powers is associated with a system of checks and balances.

Question: Which political practice did Montesquieu originate?

Question: How many divisions of the government did Montesquieu call for?

Question: What document was greatly informed by the idea of separation of powers?

Question: What kind of oversight does the separation of powers help to promote?

Question: What was the doctrine called that allowed the three branches of government to check the powers of each other?
Passage: During the Age of Enlightenment, philosophers such as John Locke advocated the principle in their writings, whereas others, such as Thomas Hobbes, strongly opposed it. Montesquieu was one of the foremost supporters of separating the legislature, the executive, and the judiciary. His writings considerably influenced the opinions of the framers of the United States Constitution.

Question: Which Enlightenment thinker supported the idea of separation of powers?

Question: Which Enlightenment thinker was against the separation of powers?

Question: Who was a leading advocate of dividing government into different branches?

Question: Whose thoughts were impacted by Montesquieu's philosophy?

Question: Who was an advocate of separation of powers?

Question: Who was an opponent of separation of powers?

Question: Who's writing were very influential on the design of the United States Constitution?