Over time, electric lighting became ubiquitous in developed countries. Segmented sleep patterns disappeared, improved nighttime lighting made more activities possible at night, and more street lights reduced urban crime.


Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.


An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the surroundings. The more transparent the lighting fixture is, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability.


Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.


Lighting is classified by intended use as general, accent, or task lighting, depending largely on the distribution of the light produced by the fixture.


Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.


A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. A torchiere is an uplight intended for ambient lighting. It is typically a floor lamp but may be wall-mounted like a sconce.


The portable or table lamp is probably the most common fixture, found in many homes and offices. The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting. Magnifier lamps are also task lighting.


The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. This would probably fall under accent lighting, though in a dark nightclub it could be considered general lighting.


In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with LED based versions.


Street Lights are used to light roadways and walkways at night. Some manufacturers are designing LED and photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures.


Floodlights can be used to illuminate outdoor playing fields or work zones during nighttime hours. The most common type of floodlights are metal halide and high pressure sodium lights.


Sometimes security lighting can be used along roadways in urban areas, or behind homes or commercial facilities. These are extremely bright lights used to deter crime. Security lights may include floodlights.


Entry lights can be used outside to illuminate and signal the entrance to a property. These lights are installed for safety, security, and for decoration.


Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.


Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.


Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.


In some design instances, materials used on walls and furniture play a key role in the lighting effect< for example dark paint tends to absorb light, making the room appear smaller and more dim than it is, whereas light paint does the opposite. In addition to paint, reflective surfaces also have an effect on lighting design.


Photometric studies (also sometimes referred to as "layouts" or "point by points") are often used to simulate lighting designs for projects before they are built or renovated. This enables architects, lighting designers, and engineers to determine whether a proposed lighting setup will deliver the amount of light intended. They will also be able to determine the contrast ratio between light and dark areas. In many cases these studies are referenced against IESNA or CIBSE recommended lighting practices for the type of application. Depending on the type of area, different design aspects may be emphasized for safety or practicality (i.e. such as maintaining uniform light levels, avoiding glare or highlighting certain areas). Specialized software is often used to create these, which typically combine the use of two-dimensional digital CAD drawings and lighting calculation software (i.e. AGi32or Dialux).


Lighting illuminates the performers and artists in a live theatre, dance, or musical performance, and is selected and arranged to create dramatic effects. Stage lighting uses general illumination technology in devices configured for easy adjustment of their output characteristics.[citation needed] The setup of stage lighting is tailored for each scene of each production. Dimmers, colored filters, reflectors, lenses, motorized or manually aimed lamps, and different kinds of flood and spot lights are among the tools used by a stage lighting designer to produce the desired effects. A set of lighting cues are prepared so that the lighting operator can control the lights in step with the performance; complex theatre lighting systems use computer control of lighting instruments.


Motion picture and television production use many of the same tools and methods of stage lighting. Especially in the early days of these industries, very high light levels were required and heat produced by lighting equipment presented substantial challenges. Modern cameras require less light, and modern light sources emit less heat.


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).


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.


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.


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.


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.


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.


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.


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.


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.


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.


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).


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


Strict separation of powers did not operate in The United Kingdom, the political structure of which served in most instances[citation needed] as a model for the government created by the U.S. Constitution.[citation needed] Under the UK Westminster system, based on parliamentary sovereignty and responsible government, Parliament (consisting of the Sovereign (King-in-Parliament), House of Lords and House of Commons) was the supreme lawmaking authority. The executive branch acted in the name of the King ("His Majesty's Government"), as did the judiciary. The King's Ministers were in most cases members of one of the two Houses of Parliament, and the Government needed to sustain the support of a majority in the House of Commons. One minister, the Lord Chancellor, was at the same time the sole judge in the Court of Chancery and the presiding officer in the House of Lords. Therefore, it may be seen that the three branches of British government often violated the strict principle of separation of powers, even though there were many occasions when the different branches of the government disagreed with each other. Some U.S. states did not observe a strict separation of powers in the 18th century. In New Jersey, the Governor also functioned as a member of the state's highest court and as the presiding officer of one house of the New Jersey Legislature. The President of Delaware was a member of the Court of Appeals; the presiding officers of the two houses of the state legislature also served in the executive department as Vice Presidents. In both Delaware and Pennsylvania, members of the executive council served at the same time as judges. On the other hand, many southern states explicitly required separation of powers. Maryland, Virginia, North Carolina and Georgia all kept the branches of government "separate and distinct."


Congress has the sole power to legislate for the United States. Under the nondelegation doctrine, Congress may not delegate its lawmaking responsibilities to any other agency. In this vein, the Supreme Court held in the 1998 case Clinton v. City of New York that Congress could not delegate a "line-item veto" to the President, by powers vested in the government by the Constitution.


Where Congress does not make great and sweeping delegations of its authority, the Supreme Court has been less stringent. One of the earliest cases involving the exact limits of non-delegation was Wayman v. Southard 23 U.S. (10 Wet.) 1, 42 (1825). Congress had delegated to the courts the power to prescribe judicial procedure; it was contended that Congress had thereby unconstitutionally clothed the judiciary with legislative powers. While Chief Justice John Marshall conceded that the determination of rules of procedure was a legislative function, he distinguished between "important" subjects and mere details. Marshall wrote that "a general provision may be made, and power given to those who are to act under such general provisions, to fill up the details."


Marshall's words and future court decisions gave Congress much latitude in delegating powers. It was not until the 1930s that the Supreme Court held a delegation of authority unconstitutional. In a case involving the creation of the National Recovery Administration called A.L.A. Schechter Poultry Corp. v. United States, 295 U.S. 495 (1935), Congress could not authorize the president to formulate codes of "fair competition." It was held that Congress must set some standards governing the actions of executive officers. The Court, however, has deemed that phrases such as "just and reasonable," "public interest" and "public convenience" suffice.


Executive power is vested, with exceptions and qualifications, in the President. By law (Section 2.) the president becomes the Commander in Chief of the Army and Navy, Militia of several states when called into service, has power to make treaties and appointments to office "with the Advice and Consent of the Senate," receive Ambassadors and Public Ministers, and "take care that the laws be faithfully executed" (Section 3.) By using these words, the Constitution does not require the president to personally enforce the law; rather, officers subordinate to the president may perform such duties. The Constitution empowers the president to ensure the faithful execution of the laws made by Congress and approved by the President. Congress may itself terminate such appointments, by impeachment, and restrict the president. Bodies such as the War Claims Commission, the Interstate Commerce Commission and the Federal Trade Commission—all quasi-judicial—often have direct Congressional oversight.


Congress often writes legislation to restrain executive officials to the performance of their duties, as laid out by the laws Congress passes. In INS v. Chadha (1983), the Supreme Court decided (a) The prescription for legislative action in Art. I, § 1—requiring all legislative powers to be vested in a Congress consisting of a Senate and a House of Representatives—and § 7—requiring every bill passed by the House and Senate, before becoming law, to be presented to the president, and, if he disapproves, to be repassed by two-thirds of the Senate and House—represents the Framers' decision that the legislative power of the Federal Government be exercised in accord with a single, finely wrought and exhaustively considered procedure. This procedure is an integral part of the constitutional design for the separation of powers. Further rulings clarified the case; even both Houses acting together cannot override Executive vetos without a 2⁄3 majority. Legislation may always prescribe regulations governing executive officers.


Judicial power—the power to decide cases and controversies—is vested in the Supreme Court and inferior courts established by Congress. The judges must be appointed by the president with the advice and consent of the Senate, hold office during good behavior and receive compensations that may not be diminished during their continuance in office. If a court's judges do not have such attributes, the court may not exercise the judicial power of the United States. Courts exercising the judicial power are called "constitutional courts."


Congress may establish "legislative courts," which do not take the form of judicial agencies or commissions, whose members do not have the same security of tenure or compensation as the constitutional court judges. Legislative courts may not exercise the judicial power of the United States. In Murray's Lessee v. Hoboken Land & Improvement Co. (1856), the Supreme Court held that a legislative court may not decide "a suit at the common law, or in equity, or admiralty," as such a suit is inherently judicial. Legislative courts may only adjudicate "public rights" questions (cases between the government and an individual and political determinations).


The president exercises a check over Congress through his power to veto bills, but Congress may override any veto (excluding the so-called "pocket veto") by a two-thirds majority in each house. When the two houses of Congress cannot agree on a date for adjournment, the president may settle the dispute. Either house or both houses may be called into emergency session by the president. The Vice President serves as president of the Senate, but he may only vote to break a tie.


The president, as noted above, appoints judges with the Senate's advice and consent. He also has the power to issue pardons and reprieves. Such pardons are not subject to confirmation by either the House of Representatives or the Senate, or even to acceptance by the recipient.


The president is the civilian Commander in Chief of the Army and Navy of the United States. He has the authority to command them to take appropriate military action in the event of a sudden crisis. However, only the Congress is explicitly granted the power to declare war per se, as well as to raise, fund and maintain the armed forces. Congress also has the duty and authority to prescribe the laws and regulations under which the armed forces operate, such as the Uniform Code of Military Justice, and requires that all Generals and Admirals appointed by the president be confirmed by a majority vote of the Senate before they can assume their office.


Courts check both the executive branch and the legislative branch through judicial review. This concept is not written into the Constitution, but was envisioned by many of the Constitution's Framers (for example, The Federalist Papers mention it). The Supreme Court established a precedent for judicial review in Marbury v. Madison. There were protests by some at this decision, born chiefly of political expediency, but political realities in the particular case paradoxically restrained opposing views from asserting themselves. For this reason, precedent alone established the principle that a court may strike down a law it deems unconstitutional.


A common misperception is that the Supreme Court is the only court that may determine constitutionality; the power is exercised even by the inferior courts. But only Supreme Court decisions are binding across the nation. Decisions of a Court of Appeals, for instance, are binding only in the circuit over which the court has jurisdiction.


The power to review the constitutionality of laws may be limited by Congress, which has the power to set the jurisdiction of the courts. The only constitutional limit on Congress' power to set the jurisdiction of the judiciary relates to the Supreme Court; the Supreme Court may exercise only appellate jurisdiction except in cases involving states and cases affecting foreign ambassadors, ministers or consuls.


The Chief Justice presides in the Senate during a president's impeachment trial. The rules of the Senate, however, generally do not grant much authority to the presiding officer. Thus, the Chief Justice's role in this regard is a limited one.


The Constitution does not explicitly indicate the pre-eminence of any particular branch of government. However, James Madison wrote in Federalist 51, regarding the ability of each branch to defend itself from actions by the others, that "it is not possible to give to each department an equal power of self-defense. In republican government, the legislative authority necessarily predominates."


Throughout America's history dominance of one of the three branches has essentially been a see-saw struggle between Congress and the president. Both have had periods of great power and weakness such as immediately after the Civil War when republicans had a majority in Congress and were able to pass major legislation and shoot down most of the president's vetoes. They also passed acts to essentially make the president subordinate to Congress, such as the Tenure of Office Act. Johnson's later impeachment also cost the presidency much political power. However the president has also exercised greater power largely during the 20th century. Both Roosevelts greatly expanded the powers of the president and wielded great power during their terms.


The first six presidents of the United States did not make extensive use of the veto power: George Washington only vetoed two bills, James Monroe one, and John Adams, Thomas Jefferson and John Quincy Adams none. James Madison, a firm believer in a strong executive, vetoed seven bills. None of the first six Presidents, however, used the veto to direct national policy. It was Andrew Jackson, the seventh President, who was the first to use the veto as a political weapon. During his two terms in office, he vetoed twelve bills—more than all of his predecessors combined. Furthermore, he defied the Supreme Court in enforcing the policy of ethnically cleansing Native American tribes ("Indian Removal"); he stated (perhaps apocryphally), "John Marshall has made his decision. Now let him enforce it!"


Some of Jackson's successors made no use of the veto power, while others used it intermittently. It was only after the Civil War that presidents began to use the power to truly counterbalance Congress. Andrew Johnson, a Democrat, vetoed several Reconstruction bills passed by the "Radical Republicans." Congress, however, managed to override fifteen of Johnson's twenty-nine vetoes. Furthermore, it attempted to curb the power of the presidency by passing the Tenure of Office Act. The Act required Senate approval for the dismissal of senior Cabinet officials. When Johnson deliberately violated the Act, which he felt was unconstitutional (Supreme Court decisions later vindicated such a position), the House of Representatives impeached him; he was acquitted in the Senate by one vote.


Johnson's impeachment was perceived to have done great damage to the presidency, which came to be almost subordinate to Congress. Some believed that the president would become a mere figurehead, with the Speaker of the House of Representatives becoming a de facto Prime Minister. Grover Cleveland, the first Democratic President following Johnson, attempted to restore the power of his office. During his first term, he vetoed over four hundred bills—twice as many bills as his twenty-one predecessors combined. He also began to suspend bureaucrats who were appointed as a result of the patronage system, replacing them with more "deserving" individuals. The Senate, however, refused to confirm many new nominations, instead demanding that Cleveland turn over the confidential records relating to the suspensions. Cleveland steadfastly refused, asserting, "These suspensions are my executive acts ... I am not responsible to the Senate, and I am unwilling to submit my actions to them for judgment." Cleveland's popular support forced the Senate to back down and confirm the nominees. Furthermore, Congress finally repealed the controversial Tenure of Office Act that had been passed during the Johnson Administration. Overall, this meant that Cleveland's Administration marked the end of presidential subordination.


Several twentieth-century presidents have attempted to greatly expand the power of the presidency. Theodore Roosevelt, for instance, claimed that the president was permitted to do whatever was not explicitly prohibited by the law—in direct contrast to his immediate successor, William Howard Taft. Franklin Delano Roosevelt held considerable power during the Great Depression. Congress had granted Franklin Roosevelt sweeping authority; in Panama Refining v. Ryan, the Court for the first time struck down a Congressional delegation of power as violative of the doctrine of separation of powers. The aforementioned Schechter Poultry Corp. v. United States, another separation of powers case, was also decided during Franklin Roosevelt's presidency. In response to many unfavorable Supreme Court decisions, Roosevelt introduced a "Court Packing" plan, under which more seats would be added to the Supreme Court for the president to fill. Such a plan (which was defeated in Congress) would have seriously undermined the judiciary's independence and power.


Richard Nixon used national security as a basis for his expansion of power. He asserted, for example, that "the inherent power of the President to safeguard the security of the nation" authorized him to order a wiretap without a judge's warrant. Nixon also asserted that "executive privilege" shielded him from all legislative oversight; furthermore, he impounded federal funds (that is to say, he refused to spend money that Congress had appropriated for government programs). In the specific cases aforementioned, however, the Supreme Court ruled against Nixon. This was also because of an ongoing criminal investigation into the Watergate tapes, even though they acknowledged the general need for executive privilege. Since then, Nixon's successors have sometimes asserted that they may act in the interests of national security or that executive privilege shields them from Congressional oversight. Though such claims have in general been more limited than Nixon's, one may still conclude that the presidency's power has been greatly augmented since the eighteenth and nineteenth centuries.


It is said[by whom?] on one side of this debate that separation of powers means that powers are shared among different branches; no one branch may act unilaterally on issues (other than perhaps minor questions), but must obtain some form of agreement across branches. That is, it is argued that "checks and balances" apply to the Judicial branch as well as to the other branches.


An example of the first view is the regulation of attorneys and judges, and the establishment of rules for the conduct of the courts, by the Congress and in the states the legislatures. Although in practice these matters are delegated to the Supreme Court, the Congress holds these powers and delegates them to the Supreme Court only for convenience in light of the Supreme Court's expertise, but can withdraw that delegation at any time.


An example of the second view at the State level is found in the view of the Florida Supreme Court, that only the Florida Supreme Court may license and regulate attorneys appearing before the courts of Florida, and only the Florida Supreme Court may set rules for procedures in the Florida courts.[citation needed] The State of New Hampshire also follows this system.[citation needed]


Architecture (Latin architectura, from the Greek ἀρχιτέκτων arkhitekton "architect", from ἀρχι- "chief" and τέκτων "builder") is both the process and the product of planning, designing, and constructing buildings and other physical structures. Architectural works, in the material form of buildings, are often perceived as cultural symbols and as works of art. Historical civilizations are often identified with their surviving architectural achievements.


The earliest surviving written work on the subject of architecture is De architectura, by the Roman architect Vitruvius in the early 1st century AD. According to Vitruvius, a good building should satisfy the three principles of firmitas, utilitas, venustas, commonly known by the original translation – firmness, commodity and delight. An equivalent in modern English would be:


According to Vitruvius, the architect should strive to fulfill each of these three attributes as well as possible. Leon Battista Alberti, who elaborates on the ideas of Vitruvius in his treatise, De Re Aedificatoria, saw beauty primarily as a matter of proportion, although ornament also played a part. For Alberti, the rules of proportion were those that governed the idealised human figure, the Golden mean. The most important aspect of beauty was therefore an inherent part of an object, rather than something applied superficially; and was based on universal, recognisable truths. The notion of style in the arts was not developed until the 16th century, with the writing of Vasari: by the 18th century, his Lives of the Most Excellent Painters, Sculptors, and Architects had been translated into Italian, French, Spanish and English.


In the early 19th century, Augustus Welby Northmore Pugin wrote Contrasts (1836) that, as the titled suggested, contrasted the modern, industrial world, which he disparaged, with an idealized image of neo-medieval world. Gothic architecture, Pugin believed, was the only "true Christian form of architecture."


The 19th-century English art critic, John Ruskin, in his Seven Lamps of Architecture, published 1849, was much narrower in his view of what constituted architecture. Architecture was the "art which so disposes and adorns the edifices raised by men ... that the sight of them" contributes "to his mental health, power, and pleasure".


For Ruskin, the aesthetic was of overriding significance. His work goes on to state that a building is not truly a work of architecture unless it is in some way "adorned". For Ruskin, a well-constructed, well-proportioned, functional building needed string courses or rustication, at the very least.


On the difference between the ideals of architecture and mere construction, the renowned 20th-century architect Le Corbusier wrote: "You employ stone, wood, and concrete, and with these materials you build houses and palaces: that is construction. Ingenuity is at work. But suddenly you touch my heart, you do me good. I am happy and I say: This is beautiful. That is Architecture".


While the notion that structural and aesthetic considerations should be entirely subject to functionality was met with both popularity and skepticism, it had the effect of introducing the concept of "function" in place of Vitruvius' "utility". "Function" came to be seen as encompassing all criteria of the use, perception and enjoyment of a building, not only practical but also aesthetic, psychological and cultural.


Among the philosophies that have influenced modern architects and their approach to building design are rationalism, empiricism, structuralism, poststructuralism, and phenomenology.


In the late 20th century a new concept was added to those included in the compass of both structure and function, the consideration of sustainability, hence sustainable architecture. To satisfy the contemporary ethos a building should be constructed in a manner which is environmentally friendly in terms of the production of its materials, its impact upon the natural and built environment of its surrounding area and the demands that it makes upon non-sustainable power sources for heating, cooling, water and waste management and lighting.


Building first evolved out of the dynamics between needs (shelter, security, worship, etc.) and means (available building materials and attendant skills). As human cultures developed and knowledge began to be formalized through oral traditions and practices, building became a craft, and "architecture" is the name given to the most highly formalized and respected versions of that craft.


It is widely assumed that architectural success was the product of a process of trial and error, with progressively less trial and more replication as the results of the process proved increasingly satisfactory. What is termed vernacular architecture continues to be produced in many parts of the world. Indeed, vernacular buildings make up most of the built world that people experience every day. Early human settlements were mostly rural. Due to a surplus in production the economy began to expand resulting in urbanization thus creating urban areas which grew and evolved very rapidly in some cases, such as that of Çatal Höyük in Anatolia and Mohenjo Daro of the Indus Valley Civilization in modern-day Pakistan.


In many ancient civilizations, such as those of Egypt and Mesopotamia, architecture and urbanism reflected the constant engagement with the divine and the supernatural, and many ancient cultures resorted to monumentality in architecture to represent symbolically the political power of the ruler, the ruling elite, or the state itself.


Early Asian writings on architecture include the Kao Gong Ji of China from the 7th–5th centuries BCE; the Shilpa Shastras of ancient India and Manjusri Vasthu Vidya Sastra of Sri Lanka.


The architecture of different parts of Asia developed along different lines from that of Europe; Buddhist, Hindu and Sikh architecture each having different characteristics. Buddhist architecture, in particular, showed great regional diversity. Hindu temple architecture, which developed around the 3rd century BCE, is governed by concepts laid down in the Shastras, and is concerned with expressing the macrocosm and the microcosm. In many Asian countries, pantheistic religion led to architectural forms that were designed specifically to enhance the natural landscape.


Islamic architecture began in the 7th century CE, incorporating architectural forms from the ancient Middle East and Byzantium, but also developing features to suit the religious and social needs of the society. Examples can be found throughout the Middle East, North Africa, Spain and the Indian Sub-continent. The widespread application of the pointed arch was to influence European architecture of the Medieval period.


The major architectural undertakings were the buildings of abbeys and cathedrals. From about 900 CE onwards, the movements of both clerics and tradesmen carried architectural knowledge across Europe, resulting in the pan-European styles Romanesque and Gothic.


In Renaissance Europe, from about 1400 onwards, there was a revival of Classical learning accompanied by the development of Renaissance Humanism which placed greater emphasis on the role of the individual in society than had been the case during the Medieval period. Buildings were ascribed to specific architects – Brunelleschi, Alberti, Michelangelo, Palladio – and the cult of the individual had begun. There was still no dividing line between artist, architect and engineer, or any of the related vocations, and the appellation was often one of regional preference.


Architecture has to do with planning and designing form, space and ambience to reflect functional, technical, social, environmental and aesthetic considerations. It requires the creative manipulation and coordination of materials and technology, and of light and shadow. Often, conflicting requirements must be resolved. The practice of Architecture also encompasses the pragmatic aspects of realizing buildings and structures, including scheduling, cost estimation and construction administration. Documentation produced by architects, typically drawings, plans and technical specifications, defines the structure and/or behavior of a building or other kind of system that is to be or has been constructed.


Nunzia Rondanini stated, "Through its aesthetic dimension architecture goes beyond the functional aspects that it has in common with other human sciences. Through its own particular way of expressing values, architecture can stimulate and influence social life without presuming that, in and of itself, it will promote social development.'


To restrict the meaning of (architectural) formalism to art for art's sake is not only reactionary; it can also be a purposeless quest for perfection or originality which degrades form into a mere instrumentality".


The architecture and urbanism of the Classical civilizations such as the Greek and the Roman evolved from civic ideals rather than religious or empirical ones and new building types emerged. Architectural "style" developed in the form of the Classical orders.


Texts on architecture have been written since ancient time. These texts provided both general advice and specific formal prescriptions or canons. Some examples of canons are found in the writings of the 1st-century BCE Roman Architect Vitruvius. Some of the most important early examples of canonic architecture are religious.


In Europe during the Medieval period, guilds were formed by craftsmen to organise their trades and written contracts have survived, particularly in relation to ecclesiastical buildings. The role of architect was usually one with that of master mason, or Magister lathomorum as they are sometimes described in contemporary documents.


A revival of the Classical style in architecture was accompanied by a burgeoning of science and engineering which affected the proportions and structure of buildings. At this stage, it was still possible for an artist to design a bridge as the level of structural calculations involved was within the scope of the generalist.


With the emerging knowledge in scientific fields and the rise of new materials and technology, architecture and engineering began to separate, and the architect began to concentrate on aesthetics and the humanist aspects, often at the expense of technical aspects of building design. There was also the rise of the "gentleman architect" who usually dealt with wealthy clients and concentrated predominantly on visual qualities derived usually from historical prototypes, typified by the many country houses of Great Britain that were created in the Neo Gothic or Scottish Baronial styles. Formal architectural training in the 19th century, for example at École des Beaux-Arts in France, gave much emphasis to the production of beautiful drawings and little to context and feasibility. Effective architects generally received their training in the offices of other architects, graduating to the role from draughtsmen or clerks.


Meanwhile, the Industrial Revolution laid open the door for mass production and consumption. Aesthetics became a criterion for the middle class as ornamented products, once within the province of expensive craftsmanship, became cheaper under machine production.


Vernacular architecture became increasingly ornamental. House builders could use current architectural design in their work by combining features found in pattern books and architectural journals.


Around the beginning of the 20th century, a general dissatisfaction with the emphasis on revivalist architecture and elaborate decoration gave rise to many new lines of thought that served as precursors to Modern Architecture. Notable among these is the Deutscher Werkbund, formed in 1907 to produce better quality machine made objects. The rise of the profession of industrial design is usually placed here. Following this lead, the Bauhaus school, founded in Weimar, Germany in 1919, redefined the architectural bounds prior set throughout history, viewing the creation of a building as the ultimate synthesis—the apex—of art, craft, and technology.


When modern architecture was first practiced, it was an avant-garde movement with moral, philosophical, and aesthetic underpinnings. Immediately after World War I, pioneering modernist architects sought to develop a completely new style appropriate for a new post-war social and economic order, focused on meeting the needs of the middle and working classes. They rejected the architectural practice of the academic refinement of historical styles which served the rapidly declining aristocratic order. The approach of the Modernist architects was to reduce buildings to pure forms, removing historical references and ornament in favor of functionalist details. Buildings displayed their functional and structural elements, exposing steel beams and concrete surfaces instead of hiding them behind decorative forms.


Architects such as Frank Lloyd Wright developed Organic architecture, in which the form was defined by its environment and purpose, with an aim to promote harmony between human habitation and the natural world with prime examples being Robie House and Fallingwater.


Architects such as Mies van der Rohe, Philip Johnson and Marcel Breuer worked to create beauty based on the inherent qualities of building materials and modern construction techniques, trading traditional historic forms for simplified geometric forms, celebrating the new means and methods made possible by the Industrial Revolution, including steel-frame construction, which gave birth to high-rise superstructures. By mid-century, Modernism had morphed into the International Style, an aesthetic epitomized in many ways by the Twin Towers of New York's World Trade Center designed by Minoru Yamasaki.


Many architects resisted modernism, finding it devoid of the decorative richness of historical styles. As the first generation of modernists began to die after WWII, a second generation of architects including Paul Rudolph, Marcel Breuer, and Eero Saarinen tried to expand the aesthetics of modernism with Brutalism, buildings with expressive sculptural facades made of unfinished concrete. But an even new younger postwar generation critiqued modernism and Brutalism for being too austere, standardized, monotone, and not taking into account the richness of human experience offered in historical buildings across time and in different places and cultures.


One such reaction to the cold aesthetic of modernism and Brutalism is the school of metaphoric architecture, which includes such things as biomorphism and zoomorphic architecture, both using nature as the primary source of inspiration and design. While it is considered by some to be merely an aspect of postmodernism, others consider it to be a school in its own right and a later development of expressionist architecture.


Beginning in the late 1950s and 1960s, architectural phenomenology emerged as an important movement in the early reaction against modernism, with architects like Charles Moore in the USA, Christian Norberg-Schulz in Norway, and Ernesto Nathan Rogers and Vittorio Gregotti in Italy, who collectively popularized an interest in a new contemporary architecture aimed at expanding human experience using historical buildings as models and precedents. Postmodernism produced a style that combined contemporary building technology and cheap materials, with the aesthetics of older pre-modern and non-modern styles, from high classical architecture to popular or vernacular regional building styles. Robert Venturi famously defined postmodern architecture as a "decorated shed" (an ordinary building which is functionally designed inside and embellished on the outside), and upheld it against modernist and brutalist "ducks" (buildings with unnecessarily expressive tectonic forms).


Since the 1980s, as the complexity of buildings began to increase (in terms of structural systems, services, energy and technologies), the field of architecture became multi-disciplinary with specializations for each project type, technological expertise or project delivery methods. In addition, there has been an increased separation of the 'design' architect [Notes 1] from the 'project' architect who ensures that the project meets the required standards and deals with matters of liability.[Notes 2] The preparatory processes for the design of any large building have become increasingly complicated, and require preliminary studies of such matters as durability, sustainability, quality, money, and compliance with local laws. A large structure can no longer be the design of one person but must be the work of many. Modernism and Postmodernism have been criticised by some members of the architectural profession who feel that successful architecture is not a personal, philosophical, or aesthetic pursuit by individualists; rather it has to consider everyday needs of people and use technology to create liveable environments, with the design process being informed by studies of behavioral, environmental, and social sciences.


Environmental sustainability has become a mainstream issue, with profound effect on the architectural profession. Many developers, those who support the financing of buildings, have become educated to encourage the facilitation of environmentally sustainable design, rather than solutions based primarily on immediate cost. Major examples of this can be found in Passive solar building design, greener roof designs, biodegradable materials, and more attention to a structure's energy usage. This major shift in architecture has also changed architecture schools to focus more on the environment. Sustainability in architecture was pioneered by Frank Lloyd Wright, in the 1960s by Buckminster Fuller and in the 1970s by architects such as Ian McHarg and Sim Van der Ryn in the US and Brenda and Robert Vale in the UK and New Zealand. There has been an acceleration in the number of buildings which seek to meet green building sustainable design principles. Sustainable practices that were at the core of vernacular architecture increasingly provide inspiration for environmentally and socially sustainable contemporary techniques. The U.S. Green Building Council's LEED (Leadership in Energy and Environmental Design) rating system has been instrumental in this.


Concurrently, the recent movements of New Urbanism, Metaphoric architecture and New Classical Architecture promote a sustainable approach towards construction, that appreciates and develops smart growth, architectural tradition and classical design. This in contrast to modernist and globally uniform architecture, as well as leaning against solitary housing estates and suburban sprawl.


The Human Development Index (HDI) is a composite statistic of life expectancy, education, and income per capita indicators, which are used to rank countries into four tiers of human development. A country scores higher HDI when the life expectancy at birth is longer, the education period is longer, and the income per capita is higher. The HDI was developed by the Pakistani economist Mahbub ul Haq, often framed in terms of whether people are able to "be" and "do" desirable things in their life, and was published by the United Nations Development Programme.


The 2010 Human Development Report introduced an Inequality-adjusted Human Development Index (IHDI). While the simple HDI remains useful, it stated that "the IHDI is the actual level of human development (accounting for inequality)," and "the HDI can be viewed as an index of 'potential' human development (or the maximum IHDI that could be achieved if there were no inequality)."


The origins of the HDI are found in the annual Development Reports of the United Nations Development Programme (UNDP). These were devised and launched by Pakistani economist Mahbub ul Haq in 1990 and had the explicit purpose "to shift the focus of development economics from national income accounting to people-centered policies". To produce the Human Development Reports, Mahbub ul Haq formed a group of development economists including Paul Streeten, Frances Stewart, Gustav Ranis, Keith Griffin, Sudhir Anand, and Meghnad Desai. Working alongside Nobel laureate Amartya Sen, they worked on capabilities and functions that provided the underlying conceptual framework. Haq was sure that a simple composite measure of human development was needed in order to convince the public, academics, and politicians that they can and should evaluate development not only by economic advances but also improvements in human well-being. Sen initially opposed this idea, but he soon went on to help Haq develop the Index. Sen was worried that it was going to be difficult to capture the full complexity of human capabilities in a single index, but Haq persuaded him that only a single number would shift the immediate attention of politicians from economic to human well-being.


LE: Life expectancy at birth
MYS: Mean years of schooling (Years that a person 25 years-of-age or older has spent in schools)
EYS: Expected years of schooling (Years that a 5-year-old child will spend in schools throughout his life)
GNIpc: Gross national income at purchasing power parity per capita


The formula defining the HDI is promulgated by the United Nations Development Programme (UNDP). In general, to transform a raw variable, say , into a unit-free index between 0 and 1 (which allows different indices to be added together), the following formula is used:


The 2015 Human Development Report by the United Nations Development Program was released on December 14, 2015, and calculates HDI values based on estimates for 2014. Below is the list of the "very high human development" countries:


The 2014 Human Development Report by the United Nations Development Program was released on July 24, 2014, and calculates HDI values based on estimates for 2013. Below is the list of the "very high human development" countries:


The Inequality-adjusted Human Development Index (IHDI) is a "measure of the average level of human development of people in a society once inequality is taken into account."


Countries in the top quartile of HDI ("very high human development" group) with a missing IHDI: New Zealand, Singapore, Hong Kong, Liechtenstein, Brunei, Qatar, Saudi Arabia, Andorra, United Arab Emirates, Bahrain, Cuba, and Kuwait.


Some countries were not included for various reasons, primarily the lack of necessary data. The following United Nations Member States were not included in the 2014 report: North Korea, Marshall Islands, Monaco, Nauru, San Marino, Somalia, India, Pakistan, South Sudan, and Tuvalu.


The 2013 Human Development Report by the United Nations Development Program was released on March 14, 2013, and calculates HDI values based on estimates for 2012. Below is the list of the "very high human development" countries:


Some countries were not included for various reasons, mainly the unavailability of certain crucial data. The following United Nations Member States were not included in the 2011 report: North Korea, Marshall Islands, Monaco, Nauru, San Marino, South Sudan, Somalia and Tuvalu.


The 2010 Human Development Report by the United Nations Development Program was released on November 4, 2010, and calculates HDI values based on estimates for 2010. Below is the list of the "very high human development" countries:


The 2010 Human Development Report was the first to calculate an Inequality-adjusted Human Development Index (IHDI), which factors in inequalities in the three basic dimensions of human development (income, life expectancy, and education). Below is a list of countries in the top quartile by IHDI:


Some countries were not included for various reasons, mainly the unavailability of certain crucial data. The following United Nations Member States were not included in the 2010 report. Cuba lodged a formal protest at its lack of inclusion. The UNDP explained that Cuba had been excluded due to the lack of an "internationally reported figure for Cuba’s Gross National Income adjusted for Purchasing Power Parity". All other indicators for Cuba were available, and reported by the UNDP, but the lack of one indicator meant that no ranking could be attributed to the country. The situation has been addressed and, in later years, Cuba has ranked as a High Human Development country.


The 2009 Human Development Report by UNDP was released on October 5, 2009, and covers the period up to 2007. It was titled "Overcoming barriers: Human mobility and development". The top countries by HDI were grouped in a new category called "very high human development". The report refers to these countries as developed countries. They are:


Some countries were not included for various reasons, such as being a non-UN member or unable or unwilling to provide the necessary data at the time of publication. Besides the states with limited recognition, the following states were also not included.


A new index was released on December 18, 2008. This so-called "statistical update" covered the period up to 2006 and was published without an accompanying Human Development Report. The update is relevant due to newly released estimates of purchasing power parities (PPP), implying substantial adjustments for many countries, resulting in changes in HDI values and, in many cases, HDI ranks.


The Human Development Report for 2007/2008 was launched in Brasília, Brazil, on November 27, 2007. Its focus was on "Fighting climate change: Human solidarity in a divided world." Most of the data used for the report are derived largely from 2005 or earlier, thus indicating an HDI for 2005. Not all UN member states choose to or are able to provide the necessary statistics.


The report showed a small increase in world HDI in comparison with last year's report. This rise was fueled by a general improvement in the developing world, especially of the least developed countries group. This marked improvement at the bottom was offset with a decrease in HDI of high income countries.


A HDI below 0.5 is considered to represent "low development". All 22 countries in that category are located in Africa. The highest-scoring Sub-Saharan countries, Gabon and South Africa, are ranked 119th and 121st, respectively. Nine countries departed from this category this year and joined the "medium development" group.


A HDI of 0.8 or more is considered to represent "high development". This includes all developed countries, such as those in North America, Western Europe, Oceania, and Eastern Asia, as well as some developing countries in Eastern Europe, Central and South America, Southeast Asia, the Caribbean, and the oil-rich Arabian Peninsula. Seven countries were promoted to this category this year, leaving the "medium development" group: Albania, Belarus, Brazil, Libya, Macedonia, Russia and Saudi Arabia.


On the following table, green arrows () represent an increase in ranking over the previous study, while red arrows () represent a decrease in ranking. They are followed by the number of spaces they moved. Blue dashes () represent a nation that did not move in the rankings since the previous study.


The list below displays the top-ranked country from each year of the Human Development Index. Norway has been ranked the highest twelve times, Canada eight times, followed by Japan which has been ranked highest three times. Iceland has been ranked highest twice.


The Human Development Index has been criticized on a number of grounds including alleged ideological biases towards egalitarianism and so-called "Western models of development", failure to include any ecological considerations, lack of consideration of technological development or contributions to the human civilization, focusing exclusively on national performance and ranking, lack of attention to development from a global perspective, measurement error of the underlying statistics, and on the UNDP's changes in formula which can lead to severe misclassification in the categorisation of 'low', 'medium', 'high' or 'very high' human development countries.


Economists Hendrik Wolff, Howard Chong and Maximilian Auffhammer discuss the HDI from the perspective of data error in the underlying health, education and income statistics used to construct the HDI. They identified three sources of data error which are due to (i) data updating, (ii) formula revisions and (iii) thresholds to classify a country’s development status and conclude that 11%, 21% and 34% of all countries can be interpreted as currently misclassified in the development bins due to the three sources of data error, respectively. The authors suggest that the United Nations should discontinue the practice of classifying countries into development bins because - they claim - the cut-off values seem arbitrary, can provide incentives for strategic behavior in reporting official statistics, and have the potential to misguide politicians, investors, charity donors and the public who use the HDI at large.[citation needed] In 2010 the UNDP reacted to the criticism and updated the thresholds to classify nations as low, medium, and high human development countries. In a comment to The Economist in early January 2011, the Human Development Report Office responded to a January 6, 2011 article in the magazine which discusses the Wolff et al. paper. The Human Development Report Office states that they undertook a systematic revision of the methods used for the calculation of the HDI and that the new methodology directly addresses the critique by Wolff et al. in that it generates a system for continuous updating of the human development categories whenever formula or data revisions take place.


The HDI has extended its geographical coverage: David Hastings, of the United Nations Economic and Social Commission for Asia and the Pacific, published a report geographically extending the HDI to 230+ economies, whereas the UNDP HDI for 2009 enumerates 182 economies and coverage for the 2010 HDI dropped to 169 countries.


Some definitions of southern Europe, also known as Mediterranean Europe, include the countries of the Iberian peninsula (Spain and Portugal), the Italian peninsula, southern France and Greece. Other definitions sometimes include the Balkan countries of southeast Europe, which are geographically in the southern part of Europe, but which have different historical, political, economic, and cultural backgrounds.


Different methods can be used to define southern Europe, including its political, economic, and cultural attributes. Southern Europe can also be defined by its natural features — its geography, climate, and flora.


Southern Europe's most emblematic climate is that of the Mediterranean climate, which has become a typically known characteristic of the area. The Mediterranean climate covers much of Portugal, Spain, Southeast France, Italy, Croatia, Albania, Montenegro, Greece, the Western and Southern coastal regions of Turkey as well as the Mediterranean islands. Those areas of Mediterranean climate present similar vegetations and landscapes throughout, including dry hills, small plains, pine forests and olive trees.


Cooler climates can be found in certain parts of Southern European countries, for example within the mountain ranges of Spain and Italy. Additionally, the north coast of Spain experiences a wetter Atlantic climate.


Southern Europe's flora is that of the Mediterranean Region, one of the phytochoria recognized by Armen Takhtajan. The Mediterranean and Submediterranean climate regions in Europe are found in much of Southern Europe, mainly in Southern Portugal, most of Spain, the southern coast of France, Italy, the Croatian coast, much of Bosnia, Montenegro, Albania, Macedonia, Greece, and the Mediterranean islands.


The period known as classical antiquity began with the rise of the city-states of Ancient Greece. Greek influence reached its zenith under the expansive empire of Alexander the Great, spreading throughout Asia.


The Roman Empire came to dominate the entire Mediterranean basin in a vast empire based on Roman law and Roman legions. It promoted trade, tolerance, and Greek culture. By 300 AD the Roman Empire was divided into the Western Roman Empire based in Rome, and the Eastern Roman Empire based in Constantinople. The attacks of the Germanic peoples of northern Europe led to the Fall of the Western Roman Empire in AD 476, a date which traditionally marks the end of the classical period and the start of the Middle Ages.


During the Middle Ages, the Eastern Roman Empire survived, though modern historians refer to this state as the Byzantine Empire. In Western Europe, Germanic peoples moved into positions of power in the remnants of the former Western Roman Empire and established kingdoms and empires of their own.


The period known as the Crusades, a series of religiously motivated military expeditions originally intended to bring the Levant back into Christian rule, began. Several Crusader states were founded in the eastern Mediterranean. These were all short-lived. The Crusaders would have a profound impact on many parts of Europe. Their Sack of Constantinople in 1204 brought an abrupt end to the Byzantine Empire. Though it would later be re-established, it would never recover its former glory. The Crusaders would establish trade routes that would develop into the Silk Road and open the way for the merchant republics of Genoa and Venice to become major economic powers. The Reconquista, a related movement, worked to reconquer Iberia for Christendom.


The Late Middle Ages represented a period of upheaval in Europe. The epidemic known as the Black Death and an associated famine caused demographic catastrophe in Europe as the population plummeted. Dynastic struggles and wars of conquest kept many of the states of Europe at war for much of the period. In the Balkans, the Ottoman Empire, a Turkish state originating in Anatolia, encroached steadily on former Byzantine lands, culminating in the Fall of Constantinople in 1453.


Beginning roughly in the 14th century in Florence, and later spreading through Europe with the development of the printing press, a Renaissance of knowledge challenged traditional doctrines in science and theology, with the Arabic texts and thought bringing about rediscovery of classical Greek and Roman knowledge.


The Reconquista of Portugal and Spain led to a series of oceanic explorations resulting in the Age of Discovery that established direct links with Africa, the Americas, and Asia, while religious wars continued to be fought in Europe, which ended in 1648 with the Peace of Westphalia. The Spanish crown maintained its hegemony in Europe and was the leading power on the continent until the signing of the Treaty of the Pyrenees, which ended a conflict between Spain and France that had begun during the Thirty Years' War. An unprecedented series of major wars and political revolutions took place around Europe and indeed the world in the period between 1610 and 1700. Observers at the time, and many historians since, have argued that wars caused the revolutions. Galileo Galilei, invented the telescope and the thermometer which allowed him to observe and describe the solar system. Leonardo da Vinci painted the most famous work in the world. Guglielmo Marconi invented the radio.


European overseas expansion led to the rise of colonial empires, producing the Columbian Exchange. The combination of resource inflows from the New World and the Industrial Revolution of Great Britain, allowed a new economy based on manufacturing instead of subsistence agriculture.


The period between 1815 and 1871 saw a large number of revolutionary attempts and independence wars. Balkan nations began to regain independence from the Ottoman Empire. Italy unified into a nation state. The capture of Rome in 1870 ended the Papal temporal power. Rivalry in a scramble for empires spread in what is known as The Age of Empire.


The outbreak of World War I in 1914 was precipitated by the rise of nationalism in Southeastern Europe as the Great Powers took up sides. The Allies defeated the Central Powers in 1918. During the Paris Peace Conference the Big Four imposed their terms in a series of treaties, especially the Treaty of Versailles.


The Nazi regime under Adolf Hitler came to power in 1933, and along with Mussolini's Italy sought to gain control of the continent by the Second World War. Following the Allied victory in the Second World War, Europe was divided by the Iron Curtain. The countries in Southeastern Europe were dominated by the Soviet Union and became communist states. The major non-communist Southern European countries joined a US-led military alliance (NATO) and formed the European Economic Community amongst themselves. The countries in the Soviet sphere of influence joined the military alliance known as the Warsaw Pact and the economic bloc called Comecon. Yugoslavia was neutal.


Italy became a major industrialized country again, due to its post-war economic miracle. The European Union (EU) involved the division of powers, with taxation, health and education handled by the nation states, while the EU had charge of market rules, competition, legal standards and environmentalism. The Soviet economic and political system collapsed, leading to the end of communism in the satellite countries in 1989, and the dissolution of the Soviet Union itself in 1991. As a consequence, Europe's integration deepened, the continent became depolarised, and the European Union expanded to subsequently include many of the formerly communist European countries – Romania and Bulgaria (2007) and Croatia (2013).


The most widely spoken family of languages in southern Europe are the Romance languages, the heirs of Latin, which have spread from the Italian peninsula, and are emblematic of Southwestern Europe. (See the Latin Arch.) By far the most common romance languages in Southern Europe are: Italian, which is spoken by over 50 million people in Italy, San Marino, and the Vatican; and Spanish, which is spoken by over 40 million people in Spain and Gibraltar. Other common romance languages include: Romanian, which is spoken in Romania and Moldova; Portuguese, which is spoken in Portugal; Catalan, which is spoken in eastern Spain; and Galician, which is spoken in northwestern Spain.


The Hellenic languages or Greek language are widely spoken in Greece and in the Greek part of Cyprus. Additionally, other varieties of Greek are spoken in small communities in parts of other European counties.


Several South Slavic languages are spoken by millions of people in Southern Europe. Serbian is spoken in Serbia, Bosnia, and Croatia; Bulgarian is spoken in Bulgaria; Croatian is spoken in Croatia and Bosnia; Bosnian is spoken in Bosnia; Slovene is spoken in Slovenia; and Macedonian is spoken in Macedonia.


English is used as a second language in parts of Southern Europe. As a primary language, however, English has only a small presence in Southern Europe, only in Gibraltar (alongside Spanish) and Malta (secondary to Maltese).


There are other language groupings in Southern Europe. Albanian is spoken in Albania, Kosovo, Macedoonia, and parts of Greece. Maltese is a Semitic language that is the official language of Malta. The Basque language is spoken in the Basque Country, a region in northern Spain and southwestern France.


The predominant religion is southern Europe is Christianity. Christianity spread throughout Southern Europe during the Roman Empire, and Christianity was adopted as the official religion of the Roman Empire in the year 380 AD. Due to the historical break of the Christian Church into the western half based in Rome and the eastern half based in Constantinople, different branches of Christianity are prodominent in different parts of Europe. Christians in the western half of Southern Europe — e.g., Portugal, Spain, Italy — are generally Roman Catholic. Christians in the eastern half of Southern Europe — e.g., Greece, Macedonia — are generally Greek Orthodox.


For its official works and publications, the United Nations Organization groups countries under a classification of regions. The assignment of countries or areas to specific groupings is for statistical convenience and does not imply any assumption regarding political or other affiliation of countries or territories by the United Nations. Southern Europe, as grouped for statistical convenience by the United Nations (the sub-regions according to the UN), includes following countries and territories:


European Travel Commission divides the European region on the basis of Tourism Decision Metrics (TDM) model. Countries which belong to the Southern/Mediterranean Europe are:


BBC Television is a service of the British Broadcasting Corporation. The corporation, which has operated in the United Kingdom under the terms of a Royal charter since 1927, has produced television programmes from its own since 1932, although the start of its regular service of television broadcasts is dated to 2 November 1936.


The domestic TV BBC television channels are broadcast without any commercial advertising and collectively they account for more than 30% of all UK viewing. The services are funded by a television licence.


The BBC operates several television networks, television stations (although there is generally very little distinction between the two terms in the UK), and related programming services in the United Kingdom. As well as being a broadcaster, the corporation also produces a large number of its own programmes in-house, thereby ranking as one of the world's largest television production companies.


Baird Television Ltd. made Britain's first television broadcast, on 30 September 1929 from its studio in Long Acre, London, via the BBC's London transmitter, using the electromechanical system pioneered by John Logie Baird. This system used a vertically-scanned image of 30 lines – just enough resolution for a close-up of one person, and with a bandwidth low enough to use existing radio transmitters. Simultaneous transmission of sound and picture was achieved on 30 March 1930, by using the BBC's new twin transmitter at Brookmans Park. By late 1930, 30 minutes of morning programmes were broadcast Monday to Friday, and 30 minutes at midnight on Tuesdays and Fridays, after BBC radio went off the air. Baird broadcasts via the BBC continued until June 1932.


The BBC began its own regular television programming from the basement of Broadcasting House, London, on 22 August 1932. The studio moved to larger quarters in 16 Portland Place, London, in February 1934, and continued broadcasting the 30-line images, carried by telephone line to the medium wave transmitter at Brookmans Park, until 11 September 1935, by which time advances in all-electronic television systems made the electromechanical broadcasts obsolete.


After a series of test transmissions and special broadcasts that began in August, regular BBC television broadcasts officially resumed on 1 October 1936, from a converted wing of Alexandra Palace in London, which housed two studios, various scenery stores, make-up areas, dressing rooms, offices, and the transmitter itself, now broadcasting on the VHF band. BBC television initially used two systems, on alternate weeks: the 240-line Baird intermediate film system and the 405-line Marconi-EMI system, each making the BBC the world's first regular high-definition television service, broadcasting Monday to Saturday from 15:00 to 16:00 and 21:00 to 22:00.


The two systems were to run on a trial basis for six months; early television sets supported both resolutions. However, the Baird system, which used a mechanical camera for filmed programming and Farnsworth image dissector cameras for live programming, proved too cumbersome and visually inferior, and ended with closedown (at 22:00) on Saturday 13 February 1937.


Initially, the station's range was officially a 40 kilometres radius of the Alexandra Palace transmitter—in practice, however, transmissions could be picked up a good deal further away, and on one occasion in 1938 were picked up by engineers at RCA in New York, who were experimenting with a British television set.


Mechanically scanned, 30-line television broadcasts by John Logie Baird began in 1929, using the BBC transmitter in London, and by 1930 a regular schedule of programmes was transmitted from the BBC antenna in Brookmans Park. Television production was switched from Baird's company to what is now known as BBC One on 2 August 1932, and continued until September 1935. Regularly scheduled electronically scanned television began from Alexandra Palace in London on 2 November 1936, to just a few hundred viewers in the immediate area. The first programme broadcast – and thus the first ever, on a dedicated TV channel – was "Opening of the BBC Television Service" at 15:00. The first major outside broadcast was the coronation of King George VI and Queen Elizabeth in May 1937. The service was reaching an estimated 25,000–40,000 homes before the outbreak of World War II which caused the service to be suspended in September 1939. The VHF broadcasts would have provided an ideal radio beacon for German bombers homing in on London, and the engineers and technicians of the service would be needed for the war effort, in particular the radar programme.


On 1 September 1939, two days before Britain declared war on Germany, the station was taken off air with little warning; the government was concerned that the VHF transmissions would act as a beacon to enemy aircraft homing in on London. Also, many of the television service's technical staff and engineers would be needed for the war effort, in particular on the radar programme. The last programme transmitted was a Mickey Mouse cartoon, Mickey's Gala Premier (1933), which was followed by test transmissions; this account refuted the popular memory according to which broadcasting was suspended before the end of the cartoon.


According to figures from Britain's Radio Manufacturers Association, 18,999 television sets had been manufactured from 1936 to September 1939, when production was halted by the war.


BBC Television returned on 7 June 1946 at 15:00. Jasmine Bligh, one of the original announcers, made the first announcement, saying, 'Good afternoon everybody. How are you? Do you remember me, Jasmine Bligh?'. The Mickey Mouse cartoon of 1939 was repeated twenty minutes later.[unreliable source?] Alexandra Palace was the home base of the channel until the early 1950s when the majority of production moved into the newly acquired Lime Grove Studios.[original research?]


Postwar broadcast coverage was extended to Birmingham in 1949 with the opening of the Sutton Coldfield transmitting station, and by the mid-1950s most of the country was covered, transmitting a 405-line interlaced image on VHF.[original research?]


Television transmissions resumed from Alexandra Palace in 1946. The BBC Television Service (renamed "BBC tv" in 1960) showed popular programming, including drama, comedies, documentaries, game shows, and soap operas, covering a wide range of genres and regularly competed with ITV to become the channel with the highest ratings for that week. The channel also introduced the science fiction show Doctor Who on 23 November 1963 - at 17:16 - which went on to become one of Britain's most iconic and beloved television programmes.


BBC TV was renamed BBC1 in 1964, after the launch of BBC2 (now BBC Two), the third television station (ITV was the second) for the UK; its remit, to provide more niche programming. The channel was due to launch on 20 April 1964, but was put off the air by a massive power failure that affected much of London, caused by a fire at Battersea Power Station. A videotape made on the opening night was rediscovered in 2003 by a BBC technician. In the end the launch went ahead the following night, hosted by Denis Tuohy holding a candle. BBC2 was the first British channel to use UHF and 625-line pictures, giving higher definition than the existing VHF 405-line system.


On 1 July 1967, BBC Two became the first television channel in Europe to broadcast regularly in colour, using the West German PAL system that is still in use today although being gradually superseded by digital systems. (BBC One and ITV began 625-line colour broadcasts simultaneously on 15 November 1969). Unlike other terrestrial channels, BBC Two does not have soap opera or standard news programming, but a range of programmes intended to be eclectic and diverse (although if a programme has high audience ratings it is often eventually repositioned to BBC One). The different remit of BBC2 allowed its first controller, Sir David Attenborough to commission the first heavyweight documentaries and documentary series such as Civilisation, The Ascent of Man and Horizon.


In 1967 Tom and Jerry cartoons first aired on BBC One, with around 2 episodes shown every evening at 17:00, with occasional morning showings on CBBC. The BBC stopped airing the famous cartoon duo in 2000.


David Attenborough was later granted sabbatical leave from his job as Controller to work with the BBC Natural History Unit which had existed since the 1950s. This unit is now famed throughout the world for producing high quality programmes with Attenborough such as Life on Earth, The Private Life of Plants, The Blue Planet, The Life of Mammals, Planet Earth and Frozen Planet.


National and regional variations also occur within the BBC One and BBC Two schedules. England's BBC One output is split up into fifteen regions (such as South West and East), which exist mainly to produce local news programming, but also occasionally opt out of the network to show programmes of local importance (such as major local events). The other nations of the United Kingdom (Wales, Scotland and Northern Ireland) have been granted more autonomy from the English network; for example, programmes are mostly introduced by local announcers, rather than by those in London. BBC One and BBC Two schedules in the other UK nations can vary immensely from BBC One and BBC Two in England.


Programmes, such as the politically fuelled Give My Head Peace (produced by BBC Northern Ireland) and the soap opera River City (produced by BBC Scotland), have been created specifically to cater for some viewers in their respective nations, who may have found programmes created for English audiences irrelevant. BBC Scotland produces daily programmes for its Gaelic-speaking viewers, including current affairs, political and children's programming such as the popular Eòrpa and Dè a-nis?. BBC Wales also produces a large amount of Welsh language programming for S4C, particularly news, sport and other programmes, especially the soap opera Pobol y Cwm ('People of the Valley'). The UK nations also produce a number of programmes that are shown across the UK, such as BBC Scotland's comedy series Chewin' the Fat, and BBC Northern Ireland's talk show Patrick Kielty Almost Live.


The BBC is also renowned for its production of costume dramas, such as Jane Austen's Pride and Prejudice and contemporary social dramas such as Boys from the Blackstuff and Our Friends in the North. The BBC has come under pressure to commission more programmes from independent British production companies, and indeed is legally required to source 25% of its output from such companies by the terms of the Broadcasting Act 1990. Programmes have also been imported mainly from English-speaking countries: notable—though no longer shown—examples include The Simpsons from the United States and Neighbours from Australia. Because of the availability of programmes in English, few programmes need use sub-titles or dubbing unlike much European television.


The BBC also introduced Ceefax, the first teletext service, starting in 1974. This service allows BBC viewers to view textual information such as the latest news on their television. CEEFAX has not made a full transition to digital television, instead being replaced by the new interactive BBCi service.


In March 2003 the BBC announced that from the end of May 2003 (subsequently deferred to 14 July) it intended to transmit all eight of its domestic television channels (including the 15 regional variations of BBC 1) unencrypted from the Astra 2D satellite. This move was estimated to save the BBC £85 million over the next five years.


While the "footprint" of the Astra 2D satellite was smaller than that of Astra 2A, from which it was previously broadcast encrypted, it meant that viewers with appropriate equipment were able to receive BBC channels "free-to-air" over much of Western Europe. Consequently, some rights concerns have needed to be resolved with programme providers such as Hollywood studios and sporting organisations, which have expressed concern about the unencrypted signal leaking out. This led to some broadcasts being made unavailable on the Sky Digital platform, such as Scottish Premier League and Scottish Cup football, while on other platforms such broadcasts were not disrupted. Later, when rights contracts were renewed, this problem was resolved.