title: Hyperloop

text: Hyperloop Transportation Technologies (HTT) reportedly signed an agreement with the government of Slovakia in March 2016 to perform impact studies, with potential links between Bratislava, Vienna, and Budapest, but there have been no further developments. In January 2017, HTT signed an agreement to explore the route Bratislava—Brno—Prague in Central Europe.


title: Hyperloop

text: In 2017, SINTEF, the largest independent research organization in Scandinavia, announced they were considering building a test lab for hyperloop in Norway.


title: Hyperloop

text: An agreement was signed in June 2017 to co-develop a hyperloop line between Seoul and Busan in South Korea.


title: Hyperloop

text: According to Musk, hyperloop would be useful on Mars as no tubes would be needed because Mars' atmosphere is about 1% the density of the Earth's at sea level. For the hyperloop concept to work on Earth, low-pressure tubes are required to reduce air resistance. However, if they were to be built on Mars, the lower air resistance would allow a hyperloop to be created with no tube, only a track, and so would be just a magnetically levitating train.


title: Hyperloop

text: In September 2013, Ansys Corporation ran computational fluid dynamics simulations to model the aerodynamics of the capsule and shear stress forces that the capsule would be subjected to. The simulation showed that the capsule design would need to be significantly reshaped to avoid creating supersonic airflow, and that the gap between the tube wall and capsule would need to be larger. Ansys employee Sandeep Sovani said the simulation showed that hyperloop has challenges but that he is convinced it is feasible.


title: Hyperloop

text: In October 2013, the development team of the OpenMDAO software framework released an unfinished, conceptual open-source model of parts of the hyperloop's propulsion system. The team asserted that the model demonstrated the concept's feasibility, although the tube would need to be in diameter, significantly larger than originally projected. However, the team's model is not a true working model of the propulsion system, as it did not account for a wide range of technical factors required to physically construct a hyperloop based on Musk's concept, and in particular had no significant estimations of component weight.


title: Hyperloop

text: In November 2013, MathWorks analyzed the proposal's suggested route and concluded that the route was mainly feasible. The analysis focused on the acceleration experienced by passengers and the necessary deviations from public roads in order to keep the accelerations reasonable; it did highlight that maintaining a trajectory along I-580 east of San Francisco at the planned speeds was not possible without significant deviation into heavily populated areas.


title: Hyperloop

text: In January 2015, a paper based on the NASA OpenMDAO open-source model reiterated the need for a larger diameter tube and a reduced cruise speed closer to Mach 0.85. It recommended removing on-board heat exchangers based on thermal models of the interactions between the compressor cycle, tube, and ambient environment. The compression cycle would only contribute 5% of the heat added to the tube, with 95% of the heat attributed to radiation and convection into the tube. The weight and volume penalty of on-board heat exchangers would not be worth the minor benefit, and regardless the steady-state temperature in the tube would only reach above ambient temperature.


title: Hyperloop

text: According to Musk, various aspects of the hyperloop have technology applications to other Musk interests, including surface transportation on Mars and electric jet propulsion.


title: Hyperloop

text: Researchers associated with MIT's department of Aeronautics and Astronautics published research in June 2017 that verified the challenge of aerodynamic design near the Kantrowitz limit that had been theorized in the original SpaceX Alpha-design concept released in 2013.


title: Hyperloop

text: In 2017, Dr. Richard Geddes and others formed the Hyperloop Advanced Research Partnership to act as a clearinghouse of Hyperloop public domain reports and data.


title: Hyperloop

text: In February 2020, Hardt Hyperloop, Hyper Poland, TransPod and Zeleros formed a consortium to drive standardization efforts, as part of a joint technical committee (JTC20) set up by European standards bodies CEN and CENELEC to develop common standards aimed at ensuring the safety and interoperability of infrastructure, rolling stock, signaling and other systems.


title: Hyperloop

text: TUM Hyperloop is a research program that emerged in 2019 from the team of hyperloop pod competition from the Technical University of Munich. The TUM Hyperloop team had won all four competitions in a row, achieving the world record of 463 km/h (288 mph), which is still valid today. The research program has the goals to investigate the technical feasibility by means of a demonstrator, as well as by simulation the economic and technical feasibility of the hyperloop system. The planned 24m demonstrator will consist of a tube and the full-size pod. The next steps after completion of the first project phase are the extension to 400m to investigate higher speeds. This is planned in the Munich area, in Taufkirchen, Ottobrunn or at the Oberpfaffenhofen airfield.


title: Hyperloop

text: EuroTube is a non-profit research organization for the development of vacuum transport technology. EuroTube is currently developing a test tube in Collombey-Muraz, Switzerland. The organization was founded in 2017 at ETH Zurich as a Swiss association and became a Swiss foundation in 2019. The test tube is planned on a 2:1 scale with a diameter of 2.2 m and designed for 900 km/h (560 mph).


title: Hyperloop

text: A number of student and non-student teams were participating in a hyperloop pod competition in 2015–16, and at least 22 of them built hardware to compete on a sponsored hyperloop test track in mid-2016.


title: Hyperloop

text: In June 2015, SpaceX announced that they would sponsor a hyperloop pod design competition and would build a subscale test track near SpaceX's headquarters in Hawthorne, California, for the competitive event in 2016. SpaceX stated in their announcement, "Neither SpaceX nor Elon Musk is affiliated with any Hyperloop companies. While we are not developing a commercial Hyperloop ourselves, we are interested in helping to accelerate development of a functional Hyperloop prototype."


title: Hyperloop

text: More than 700 teams had submitted preliminary applications by July, and detailed competition rules were released in August. "Intent to Compete" submissions were due in September 2015 with more detailed tube and technical specification released by SpaceX in October. A preliminary design briefing was held in November 2015, where more than 120 student engineering teams were selected to submit "Final Design Packages" due by 13 January 2016.


title: Hyperloop

text: A "Design Weekend" was held at Texas A&M University 29–30 January 2016, for all invited entrants. Engineers from the Massachusetts Institute of Technology were named the winners of the competition. While the University of Washington team won the Safety Subsystem Award, Delft University won the Pod Innovation Award as well as the second place, followed by the University of Wisconsin–Madison, Virginia Tech, and the University of California, Irvine. In the Design Category, the winner team was Hyperloop UPV from Universitat Politecnica de Valencia, Spain. On 29 January 2017, Delft Hyperloop (Delft University of Technology) won the prize for the "best overall design" at the final stage of the SpaceX hyperloop competition, while WARR Hyperloop of the Technical University of Munich won the prize for "fastest pod". The Massachusetts Institute of Technology placed third.


title: Hyperloop

text: The second hyperloop pod competition took place from 25 to 27 August 2017. The only judging criteria being top speed provided it is followed by successful deceleration. WARR Hyperloop from the Technical University of Munich won the competition by reaching a top speed of 324 km/h (201 mph).


title: Hyperloop

text: A third hyperloop pod competition took place in July 2018. The defending champions, the WARR Hyperloop team from the Technical University of Munich, beat their own record with a top speed of 457 km/h (284 mph) during their run. The fourth competition in August 2019 saw the team from the Technical University of Munich, now known as TUM Hyperloop (by NEXT Prototypes e.V.), again winning the competition and beating their own record with a top speed of 463 km/h (288 mph).


title: Hyperloop

text: Some critics of hyperloop focus on the experience—possibly unpleasant and frightening—of riding in a narrow, sealed, windowless capsule inside a sealed steel tunnel, that is subjected to significant acceleration forces; high noise levels due to air being compressed and ducted around the capsule at near-sonic speeds; and the vibration and jostling. Even if the tube is initially smooth, ground may shift with seismic activity. At high speeds, even minor deviations from a straight path may add considerable buffeting. This is in addition to practical and logistical questions regarding how to best deal with safety issues such as equipment malfunction, accidents, and emergency evacuations.


title: Hyperloop

text: Other maglev trains are already in use, which avoid much of the added costs of hyperloop. The SCMaglev in Japan has demonstrated without a vacuum tube, by using an extremely aerodynamic train design. It also avoids the cost and time required to pressurize and depressurize the exit and entry points of a hyperloop tube.


title: Hyperloop

text: There is also the criticism of design technicalities in the tube system. John Hansman, professor of aeronautics and astronautics at MIT, has stated problems, such as how a slight misalignment in the tube would be compensated for and the potential interplay between the air cushion and the low-pressure air. He has also questioned what would happen if the power were to go out when the pod was miles away from a city. UC Berkeley physics professor Richard Muller has also expressed concern regarding "[the Hyperloop's] novelty and the vulnerability of its tubes, [which] would be a tempting target for terrorists", and that the system could be disrupted by everyday dirt and grime.


title: Hyperloop

text: The alpha proposal projected that cost savings compared with conventional rail would come from a combination of several factors. The small profile and elevated nature of the alpha route would enable hyperloop to be constructed primarily in the median of Interstate 5. However, whether this would be truly feasible is a matter of debate. The low profile would reduce tunnel boring requirements and the light weight of the capsules is projected to reduce construction costs over conventional passenger rail. It was asserted that there would be less right-of-way opposition and environmental impact as well due to its small, sealed, elevated profile versus that of a rail easement; however, other commentators contend that a smaller footprint does not guarantee less opposition. In criticizing this assumption, mass transportation writer Alon Levy said, "In reality, an all-elevated system (which is what Musk proposes with the Hyperloop) is a bug rather than a feature. Central Valley land is cheap; pylons are expensive, as can be readily seen by the costs of elevated highways and trains all over the world". Michael Anderson, a professor of agricultural and resource economics at UC Berkeley, predicted that costs would amount to around .


title: Hyperloop

text: No total ticket price was suggested in the alpha design in Elon Musk's initial whitepaper. Projected low ticket prices by hyperloop developers have been questioned by Dan Sperling, director of the Institute of Transportation Studies at UC Davis, who stated that "there's no way the economics on that would ever work out." Some critics have argued that, since hyperloops are designed to carry fewer passengers than typical public train systems, it could make it difficult to price tickets to cover the costs of construction and running.


title: Hyperloop

text: The early cost estimates of the hyperloop are a subject of debate. A number of economists and transportation experts have expressed the belief that the price tag dramatically understates the cost of designing, developing, constructing, and testing an all-new form of transportation. "The Economist" said that the estimates are unlikely to "be immune to the hypertrophication of cost that every other grand infrastructure project seems doomed to suffer."


title: Hyperloop

text: Political impediments to the construction of such a project in California will be very large. There is a great deal of "political and reputation capital" invested in the existing mega-project of California High-Speed Rail. Replacing that with a different design would not be straightforward given California's political economy. Texas has been suggested as an alternate for its more amenable political and economic environment.


title: Hyperloop

text: Building a successful hyperloop sub-scale demonstration project could reduce the political impediments and improve cost estimates. Musk has suggested that he may be personally involved in building a demonstration prototype of the hyperloop concept, including funding the development effort, yet to happen as of 2020.


title: Hyperloop

text: The solar panels Musk plans to install along the length of the hyperloop system have been criticized by engineering professor Roger Goodall of Loughborough University, as not being feasible enough to return enough energy to power the hyperloop system, arguing that the air pumps and propulsion would require much more power than the solar panels could generate.


title: Hyperloop

text: According to "The New York Times", "The central impediment" to the hyperloop is that it "would require creating an entire infrastructure. That means constructing miles-long systems of tubes and stations, acquiring rights of way, adhering to government regulations and standards, and avoiding changes to the ecology along its routes."


title: Hyperloop

text: The concept of transportation of passengers in pneumatic tubes is not new. The first patent to transport goods in tubes was created in 1799 by the British mechanical engineer and inventor George Medhurst. In 1812, Medhurst wrote a book detailing his idea of transporting passengers and goods through air-tight tubes using air propulsion.


title: Hyperloop

text: In the early 1800s, there were other similar systems proposed or experimented with and were generally known as atmospheric railway projects, though this term is now also used for systems where the propulsion is provided by a separate pneumatic tube to the train tunnel itself.


title: Hyperloop

text: One of the earliest constructions was the Dalkey Atmospheric Railway which operated near Dublin between 1844 and 1854.


title: Hyperloop

text: The Crystal Palace pneumatic railway operated in London around 1864 and used large fans, some in diameter, that were powered by a steam engine. The tunnels are now lost but the line operated successfully for over a year.


title: Hyperloop

text: Operated from 1870 to 1873, the Beach Pneumatic Transit was a one-block-long prototype of an underground tube transport public transit system in New York City. The system worked at near-atmospheric pressure, and the passenger car moved by means of higher pressure air applied to the back of the car while comparatively lower pressure air was maintained on the front of the car.


title: Hyperloop

text: In the 1910s, vacuum trains were first described by American rocket pioneer Robert Goddard. While the hyperloop has significant innovations over early proposals for reduced pressure or vacuum-tube transportation apparatus, the work of Goddard "appears to have the greatest overlap with the Hyperloop".


title: Hyperloop

text: In 1981, Princeton physicist Gerard K. O'Neill wrote about transcontinental trains using magnetic propulsion in his book "". Though being a work of fiction, this book was an attempt to predict future technologies in everyday life. In his prediction, he envisioned these trains which used magnetic levitation running in tunnels which had much of the air evacuated to increase speed and significantly reduce friction. He also demonstrated a scale prototype device that accelerated an object using magnetic propulsion to high speeds. It was called a mass driver and was a central theme in his non-fiction book on space colonization "The High Frontier".


title: Hyperloop

text: Swissmetro was a proposal to run a maglev train in a low-pressure environment. Concessions were granted to Swissmetro in the early 2000s to connect the Swiss cities of St. Gallen, Zurich, Basel, and Geneva. Studies of commercial feasibility reached differing conclusions and the vactrain was never built.


title: Hyperloop

text: The ET3 Global Alliance (ET3) was founded by Daryl Oster in 1997 with the goal of establishing a global transportation system using passenger capsules in frictionless maglev full-vacuum tubes. Oster and his team met with Elon Musk on 18 September 2013, to discuss the technology, resulting in Musk promising an investment in a prototype of ET3's proposed design.


title: Hyperloop

text: From 2003 Franco Cotana led the development of Pipenet which had a small bore evacuated tube for moving freight at up to using linear synchronous motors and magnetic levitation. A prototype system - long and in diameter - was constructed in Italy in 2005. However development stopped after funding ceased.


title: Hyperloop

text: China was reported to be building a vacuum based maglev train in August 2010 according to a laboratory at Southwest Jiaotong University. It was expected to cost ( at the August 2010 exchange rate) more per kilometer than regular high-speed rail. In 2018 a loop test track was completed to test some of the technology.


title: Hyperloop

text: In 2018, the new concept of creating and using intermodal hyperloop capsules was presented. After detaching the drive elements, capsules could be used in a way similar to traditional containers for fast transport of goods or individuals. It has been proposed that specialized airplanes, dedicated high-speed trains, road tractors or watercrafts perform "last mile" transport for solving the problem of fast transportation to centers where hyperloop terminals are locally unavailable or infeasible to be constructed.


title: Hyperloop

text: In May 2021, it was reported that a low-vacuum sealed tube test system capable of reaching speeds around had begun construction in Datong, Shanxi Province. An initial section is to be completed by July 2022 and a test line within two years. The line will be built by the North University of China and the Third Research Institute of China Aerospace Science and Industry Corporation.


title: Cyanide

text: Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.


title: Cyanide

text: In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom.


title: Cyanide

text: In inorganic cyanides, the cyanide group is present as the anion . Soluble salts such as sodium cyanide (NaCN) and potassium cyanide (KCN) are highly toxic. Hydrocyanic acid, also known as hydrogen cyanide, or HCN, is a highly volatile liquid that is produced on a large scale industrially. It is obtained by acidification of cyanide salts.


title: Cyanide

text: Organic cyanides are usually called nitriles. In nitriles, the group is linked by a covalent bond to carbon. For example, in acetonitrile (), the cyanide group is bonded to methyl (). Although nitriles generally do not release cyanide ions, the cyanohydrins do and are thus rather toxic.


title: Cyanide

text: The cyanide ion is isoelectronic with carbon monoxide and with molecular nitrogen N≡N. A triple bond exists between C and N. The negative charge is concentrated on carbon C.


title: Cyanide

text: Cyanides are produced by certain bacteria, fungi, and algae. It is an antifeedant in a number of plants. Cyanides are found in substantial amounts in certain seeds and fruit stones, e.g., those of bitter almonds, apricots, apples, and peaches. Chemical compounds that can release cyanide are known as cyanogenic compounds. In plants, cyanides are usually bound to sugar molecules in the form of cyanogenic glycosides and defend the plant against herbivores. Cassava roots (also called manioc), an important potato-like food grown in tropical countries (and the base from which tapioca is made), also contain cyanogenic glycosides.


title: Cyanide

text: The Madagascar bamboo "Cathariostachys madagascariensis" produces cyanide as a deterrent to grazing. In response, the golden bamboo lemur, which eats the bamboo, has developed a high tolerance to cyanide.


title: Cyanide

text: The cyanide radical •CN has been identified in interstellar space. Cyanogen, , is used to measure the temperature of interstellar gas clouds.


title: Cyanide

text: Hydrogen cyanide is produced by the combustion or pyrolysis of certain materials under oxygen-deficient conditions. For example, it can be detected in the exhaust of internal combustion engines and tobacco smoke. Certain plastics, especially those derived from acrylonitrile, release hydrogen cyanide when heated or burnt.


title: Cyanide

text: The hydrogenase enzymes contain cyanide ligands attached to iron in their active sites. The biosynthesis of cyanide in the [NiFe]-hydrogenases proceeds from carbamoyl phosphate, which converts to cysteinyl thiocyanate, the donor.


title: Cyanide

text: In IUPAC nomenclature, organic compounds that have a –C≡N functional group are called nitriles. An example of a nitrile is acetonitrile, . Nitriles usually do not release cyanide ions. A functional group with a hydroxyl –OH and cyanide –CN bonded to the same carbon atom is called cyanohydrin (C(–OH)(–CN)). Unlike nitriles, cyanohydridins do release hydrogen cyanide. In inorganic chemistry, salts containing the ion are referred to as cyanides.


title: Cyanide

text: Cyanide is basic. The p"K" of hydrogen cyanide is 9.21. Thus, addition of acids stronger than hydrogen cyanide to solutions of cyanide salts releases hydrogen cyanide.


title: Cyanide

text: Cyanide is unstable in water, but the reaction is slow until about 170 °C. It undergoes hydrolysis to give ammonia and formate, which are far less toxic than cyanide:


title: Cyanide

text: Because of the cyanide anion's high nucleophilicity, cyano groups are readily introduced into organic molecules by displacement of a halide group (e.g., the chloride on methyl chloride). In general, organic cyanides are called nitriles. In organic synthesis, cyanide is a C-1 synthon; i.e., it can be used to lengthen a carbon chain by one, while retaining the ability to be functionalized.


title: Cyanide

text: The cyanide ion is a reductant and is oxidized by strong oxidizing agents such as molecular chlorine (), hypochlorite (), and hydrogen peroxide (). These oxidizers are used to destroy cyanides in effluents from gold mining.


title: Cyanide

text: The cyanide anion reacts with transition metals to form M-CN bonds. This reaction is the basis of cyanide's toxicity. The high affinities of metals for this anion can be attributed to its negative charge, compactness, and ability to engage in π-bonding.


title: Cyanide

text: Among the most important cyanide coordination compounds are the potassium ferrocyanide and the pigment Prussian blue, which are both essentially nontoxic due to the tight binding of the cyanides to a central iron atom.


title: Cyanide

text: Prussian blue was first accidentally made around 1706, by heating substances containing iron and carbon and nitrogen, and other cyanides made subsequently (and named after it). Among its many uses, Prussian blue gives the blue color to blueprints, bluing, and cyanotypes.


title: Cyanide

text: The principal process used to manufacture cyanides is the Andrussow process in which gaseous hydrogen cyanide is produced from methane and ammonia in the presence of oxygen and a platinum catalyst.


title: Cyanide

text: Sodium cyanide, the precursor to most cyanides, is produced by treating hydrogen cyanide with sodium hydroxide:


title: Cyanide

text: Many cyanides are highly toxic. The cyanide anion is an inhibitor of the enzyme cytochrome c oxidase (also known as aa), the fourth complex of the electron transport chain found in the inner membrane of the mitochondria of eukaryotic cells. It attaches to the iron within this protein. The binding of cyanide to this enzyme prevents transport of electrons from cytochrome c to oxygen. As a result, the electron transport chain is disrupted, meaning that the cell can no longer aerobically produce ATP for energy. Tissues that depend highly on aerobic respiration, such as the central nervous system and the heart, are particularly affected. This is an example of histotoxic hypoxia.


title: Cyanide

text: The most hazardous compound is hydrogen cyanide, which is a gas and kills by inhalation. For this reason, an air respirator supplied by an external oxygen source must be worn when working with hydrogen cyanide. Hydrogen cyanide is produced by adding acid to a solution containing a cyanide salt. Alkaline solutions of cyanide are safer to use because they do not evolve hydrogen cyanide gas. Hydrogen cyanide may be produced in the combustion of polyurethanes; for this reason, polyurethanes are not recommended for use in domestic and aircraft furniture. Oral ingestion of a small quantity of solid cyanide or a cyanide solution of as little as 200 mg, or exposure to airborne cyanide of 270 ppm, is sufficient to cause death within minutes.


title: Cyanide

text: Organic nitriles do not readily release cyanide ions, and so have low toxicities. By contrast, compounds such as trimethylsilyl cyanide readily release HCN or the cyanide ion upon contact with water.


title: Cyanide

text: Hydroxocobalamin reacts with cyanide to form cyanocobalamin, which can be safely eliminated by the kidneys. This method has the advantage of avoiding the formation of methemoglobin (see below). This antidote kit is sold under the brand name Cyanokit and was approved by the U.S. FDA in 2006.


title: Cyanide

text: An older cyanide antidote kit included administration of three substances: amyl nitrite pearls (administered by inhalation), sodium nitrite, and sodium thiosulfate. The goal of the antidote was to generate a large pool of ferric iron () to compete for cyanide with cytochrome a (so that cyanide will bind to the antidote rather than the enzyme). The nitrites oxidize hemoglobin to methemoglobin, which competes with cytochrome oxidase for the cyanide ion. Cyanmethemoglobin is formed and the cytochrome oxidase enzyme is restored. The major mechanism to remove the cyanide from the body is by enzymatic conversion to thiocyanate by the mitochondrial enzyme rhodanese. Thiocyanate is a relatively non-toxic molecule and is excreted by the kidneys. To accelerate this detoxification, sodium thiosulfate is administered to provide a sulfur donor for rhodanese, needed in order to produce thiocyanate.


title: Cyanide

text: Minimum risk levels (MRLs) may not protect for delayed health effects or health effects acquired following repeated sublethal exposure, such as hypersensitivity, asthma, or bronchitis. MRLs may be revised after sufficient data accumulates.


title: Cyanide

text: Cyanide is mainly produced for the mining of silver and gold: It helps dissolve these metals allowing separation from the other solids. In the "cyanide process", finely ground high-grade ore is mixed with the cyanide (at a ratio of about 1:500 parts NaCN to ore); low-grade ores are stacked into heaps and sprayed with a cyanide solution (at a ratio of about 1:1000 parts NaCN to ore). The precious metals are complexed by the cyanide anions to form soluble derivatives, e.g., (dicyanoargentate(I)) and (dicyanoaurate(I)). Silver is less "noble" than gold and often occurs as the sulfide, in which case redox is not invoked (no is required). Instead, a displacement reaction occurs:


title: Cyanide

text: The "pregnant liquor" containing these ions is separated from the solids, which are discarded to a tailing pond or spent heap, the recoverable gold having been removed. The metal is recovered from the "pregnant solution" by reduction with zinc dust or by adsorption onto activated carbon. This process can result in environmental and health problems. A number of environmental disasters have followed the overflow of tailing ponds at gold mines. Cyanide contamination of waterways has resulting in numerous cases of human and aquatic species mortality.


title: Cyanide

text: Aqueous cyanide is hydrolyzed rapidly, especially in sunlight. It can mobilize some heavy metals such as mercury if present. Gold can also be associated with arsenopyrite (FeAsS), which is similar to iron pyrite (fool's gold), wherein half of the sulfur atoms are replaced by arsenic. Gold-containing arsenopyrite ores are similarly reactive toward inorganic cyanide.


title: Cyanide

text: The second major application of alkali metal cyanides (after mining) is in the production of CN-containing compounds, usually nitriles. Acyl cyanides are produced from acyl chlorides and cyanide. Cyanogen, cyanogen chloride, and the trimer cyanuric chloride are derived from alkali metal cyanides.


title: Cyanide

text: The cyanide compound sodium nitroprusside is used mainly in clinical chemistry to measure urine ketone bodies mainly as a follow-up to diabetic patients. On occasion, it is used in emergency medical situations to produce a rapid decrease in blood pressure in humans; it is also used as a vasodilator in vascular research. The cobalt in artificial vitamin B contains a cyanide ligand as an artifact of the purification process; this must be removed by the body before the vitamin molecule can be activated for biochemical use. During World War I, a copper cyanide compound was briefly used by Japanese physicians for the treatment of tuberculosis and leprosy.


title: Cyanide

text: Cyanides are illegally used to capture live fish near coral reefs for the aquarium and seafood markets. The practice is controversial, dangerous, and damaging but is driven by the lucrative exotic fish market.


title: Cyanide

text: Poachers in Africa have been known to use cyanide to poison waterholes, to kill elephants for their ivory.


title: Cyanide

text: M44 cyanide devices are used in the United States to kill coyotes and other canids. Cyanide is also used for pest control in New Zealand, particularly for possums, an introduced marsupial that threatens the conservation of native species and spreads tuberculosis amongst cattle. Possums can become bait shy but the use of pellets containing the cyanide reduces bait shyness. Cyanide has been known to kill native birds, including the endangered kiwi. Cyanide is also effective for controlling the dama wallaby, another introduced marsupial pest in New Zealand. A licence is required to store, handle and use cyanide in New Zealand.


title: Cyanide

text: Cyanides are used as insecticides for fumigating ships. Cyanide salts are used for killing ants, and have in some places been used as rat poison (the less toxic poison arsenic is more common).


title: Cyanide

text: Potassium ferrocyanide is used to achieve a blue color on cast bronze sculptures during the final finishing stage of the sculpture. On its own, it will produce a very dark shade of blue and is often mixed with other chemicals to achieve the desired tint and hue. It is applied using a torch and paint brush while wearing the standard safety equipment used for any patina application: rubber gloves, safety glasses, and a respirator. The actual amount of cyanide in the mixture varies according to the recipes used by each foundry.


title: Cyanide

text: Although usually thought to be toxic, cyanide and cyanohydrins increase germination in various plant species.


title: Cyanide

text: Common salts such as sodium cyanide are involatile but water-soluble, so are poisonous by ingestion. Hydrogen cyanide is a gas, making it more indiscriminately dangerous, however it is lighter than air and rapidly disperses up into the atmosphere, which makes it ineffective as a chemical weapon. Poisoning by hydrogen cyanide is more effective in an enclosed space, such as a gas chamber. Most significantly, hydrogen cyanide released from pellets of Zyklon-B was used extensively in the extermination camps of the Holocaust.


title: Cyanide

text: Because of the high stability of their complexation with iron, ferrocyanides (Sodium ferrocyanide E535, Potassium ferrocyanide E536, and Calcium ferrocyanide E538) do not decompose to lethal levels in the human body and are used in the food industry as, e.g., an anticaking agent in table salt.


title: Cyanide

text: Cyanide is quantified by potentiometric titration, a method widely used in gold mining. It can also be determined by titration with silver ion.


title: Cyanide

text: Some analyses begin with an air-purge of an acidified boiling solution, sweeping the vapors into a basic absorber solution. The cyanide salt absorbed in the basic solution is then analyzed.


title: Cyanide

text: Because of the notorious toxicity of cyanide, many methods have been investigated. Benzidine gives a blue coloration in the presence of ferricyanide. Iron(II) sulfate added to a solution of cyanide, such as the filtrate from the sodium fusion test, gives prussian blue. A solution of "para"-benzoquinone in DMSO reacts with inorganic cyanide to form a cyanophenol, which is fluorescent. Illumination with a UV light gives a green/blue glow if the test is positive.


title: Overton window

text: The Overton window is the range of policies politically acceptable to the mainstream population at a given time. It is also known as the window of discourse.


title: Overton window

text: The term is named after American policy analyst Joseph Overton, who stated that an idea's political viability depends mainly on whether it falls within this range, rather than on politicians' individual preferences. According to Overton, the window frames the range of policies that a politician can recommend without appearing too extreme to gain or keep public office given the climate of public opinion at that time.


title: Overton window

text: Overton described a spectrum from "more free" to "less free" with regard to government intervention, oriented vertically on an axis, to avoid comparison with the left/right political spectrum. As the spectrum moves or expands, an idea at a given location may become more or less politically acceptable. After Overton's death, his Mackinac Center for Public Policy colleague Joseph Lehman further developed the idea and named it after Overton.


title: Overton window

text: Political commentator Joshua Treviño has postulated that the six degrees of acceptance of public ideas are roughly:


title: Overton window

text: The Overton window is an approach to identifying the ideas that define the spectrum of acceptability of governmental policies. Politicians can act only within the acceptable range. Shifting the Overton window involves proponents of policies outside the window persuading the public to expand the window. Proponents of current policies, or similar ones within the window, seek to convince people that policies outside it should be deemed unacceptable. According to Lehman, who coined the term, "The most common misconception is that lawmakers themselves are in the business of shifting the Overton window. That is absolutely false. Lawmakers are actually in the business of detecting where the window is, and then moving to be in accordance with it."


title: Overton window

text: According to Lehman, the concept is just a description of how ideas work, not advocacy of extreme policy proposals. In an interview with "The New York Times", he said, "It just explains how ideas come in and out of fashion, the same way that gravity explains why something falls to the earth. I can use gravity to drop an anvil on your head, but that would be wrong. I could also use gravity to throw you a life preserver; that would be good."


title: Sistine Chapel ceiling

text: The Sistine Chapel ceiling (), painted in fresco by Michelangelo between 1508 and 1512, is a cornerstone work of High Renaissance art. The Sistine Chapel is the large papal chapel built within the Vatican between 1477 and 1480 by Pope Sixtus IV, for whom the chapel is named. The ceiling was painted at the commission of Pope Julius II.


title: Sistine Chapel ceiling

text: The ceiling's various painted elements form part of a larger scheme of decoration within the chapel. Prior to Michelangelo's contribution, the walls were painted by several leading artists of the late 15th century including Sandro Botticelli, Domenico Ghirlandaio, and Pietro Perugino. After the ceiling was painted, Raphael created a set of large tapestries (1515–1516) to cover the lower portion of the wall. Michelangelo returned to the chapel to create "The Last Judgment", a large wall fresco situated behind the altar. The chapel's decoration illustrates much of the doctrine of the Catholic Church, serving as the location for papal conclaves and many other important services.


title: Sistine Chapel ceiling

text: Central to the ceiling decoration are nine scenes from the Book of Genesis, including the famous "Creation of Adam". The complex design includes several sets of figures, some clothed and some nude, allowing Michelangelo to fully demonstrate his skill in depicting the human figure in a wide variety of poses. The ceiling was immediately well-received and imitated by other artists, continuing to the present. It has been restored multiple times, most recently in the late 20th century.


title: Sistine Chapel ceiling

text: The walls of the Sistine Chapel had been decorated 20 years before Michelangelo's work on the ceiling. Following this, Raphael designed a set of tapestries (1515–1516) to cover the lowest of three levels; the surviving tapestries are still hung on special occasions. The middle level contains a complex scheme of frescoes illustrating the "Life of Christ" on the right side and the "Life of Moses" on the left side. It was carried out by some of the most renowned Renaissance painters: Sandro Botticelli, Domenico Ghirlandaio, Pietro Perugino, Pinturicchio, Luca Signorelli, and Cosimo Rosselli. The upper level of the walls contains the windows, between which are painted pairs of illusionistic niches with representations of the first 32 popes.


title: Sistine Chapel ceiling

text: The original ceiling painting was by Pier Matteo d'Amelia, and had depicted stars over a blue background like the ceiling of the Arena Chapel decorated by Giotto at Padua. For six months in 1504, a diagonal crack in the chapel's vault had made the chapel unusable, and Pope Julius II (Giuliano della Rovere) had the damaged painting removed by Piero Roselli, a friend of Michelangelo.


title: Sistine Chapel ceiling

text: Julius II was a "warrior pope" who in his papacy undertook an aggressive campaign for political control to unite and empower Italy under the leadership of the Catholic Church. He invested in symbolism to display his temporal power, such as his procession, in which he (in the Classical manner) rode a chariot through a triumphal arch after one of his many military victories. Julius II's project to rebuild St. Peter's Basilica would distinguish it as the most potent symbol of the source of papal power; he ultimately demolished and replaced the original basilica with a grander one intended to house his own tomb.


title: Sistine Chapel ceiling

text: The pope summoned Michelangelo to Rome in early 1505 and commissioned him to design his tomb, forcing the artist to leave Florence with his planned "Battle of Cascina" painting unfinished. By this time, Michelangelo was established as an artist; both he and Julius II had hot tempers and soon argued. On 17 April 1506, Michelangelo left Rome in secret for Florence, remaining there until the Florentine government pressed him to return to the pope.


title: Sistine Chapel ceiling

text: In 1506, the same year the foundation stone was laid for the new St. Peter's, Julius II conceived a programme to paint the ceiling of the Sistine Chapel. It is probable that, because the chapel was the site of regular meetings and Masses of an elite body of officials known as the Papal Chapel (who would observe the decorations and interpret their theological and temporal significance), it was Julius II's intention and expectation that the iconography of the ceiling was to be read with many layers of meaning.


title: Sistine Chapel ceiling

text: The scheme proposed by the pope was for twelve large figures of the Apostles to occupy the pendentives. Michelangelo negotiated for a grander, much more complex scheme and was finally permitted, in his own words, "to do as I liked". It has been suggested that Augustinian friar and cardinal Giles of Viterbo could have influenced the ceiling's theological layout. Many writers consider that Michelangelo had the intellect, the biblical knowledge, and the powers of invention to have devised the scheme himself. This is supported by Michelangelo's biographer Ascanio Condivi's statement that the artist read and reread the Old Testament while he was painting the ceiling, drawing his inspiration from the words of the scripture, rather than from the established traditions of sacral art.


title: Sistine Chapel ceiling

text: On 10 May 1506, Piero Roselli wrote to Michelangelo on behalf of the pope. In this letter, Roselli mentions that papal court architect Donato Bramante doubted that Michelangelo could take on such a large fresco project, as he had limited experience in the medium. According to Bramante, Michelangelo stated his refusal. In November 1506 Michelangelo went to Bologna, where he received a commission from the pope to construct a colossal bronze statue of him conquering the Bolognese. After he completed this in early 1508, Michelangelo returned to Rome expecting to resume work on the papal tomb, but this had been quietly set aside.


title: Sistine Chapel ceiling

text: Michelangelo was instead commissioned for a cycle of frescoes on the vault and upper walls of the Sistine Chapel. Michelangelo, who was not primarily a painter but a sculptor, was reluctant to take on the work; he suggested that his young rival Raphael take it on instead. The pope was persistent; according to Giorgio Vasari, he was provoked by Bramante to insist that Michelangelo take on the project, leaving him little choice but to accept. The contract was signed on 8 May 1508, with a promised fee of 3,000 ducats (approximately US$600,000 in gold in 2021). At the pope's behest, Bramante built the initial scaffolding, hung via ropes from holes in the ceiling. This method displeased Michelangelo as it would force him to paint around the holes, and he had freestanding scaffolding constructed instead. This was built by Piero Roselli, who subsequently roughcasted the ceiling. Michelangelo initially sought to engage assistants who were more well-versed in fresco-painting, but he was unable to find suitable candidates and determined to paint the whole ceiling alone. Among the Florentine artists whom Michelangelo brought to Rome in the hope of assisting in the fresco, Vasari names Francesco Granacci, Giuliano Bugiardini, Jacopo di Sandro, l'Indaco the Elder, Agnolo di Domenico, and Aristotile.


title: Sistine Chapel ceiling

text: Michelangelo soon began his work, starting at the west end with the "Drunkenness of Noah" and the "Prophet Zechariah" and working backwards through the narrative to the "Creation of Eve", in the vault's fifth bay, finished in September 1510. The first half of the ceiling was unveiled with a preliminary showing on 14 August 1511 and an official viewing the next day. A long hiatus in painting occurred as new scaffolding was made ready. The second half of the ceiling's frescoes were done swiftly, and the finished work was revealed on 31 October 1512, All Hallows' Eve, being shown to the public by the next day, All Saints' Day. Michelangelo's final scheme for the ceiling includes over 300 figures.


title: Sistine Chapel ceiling

text: Vasari states that "When the chapel was uncovered, people from everywhere [rushed] to see it, and the sight of it alone was sufficient to leave them amazed and speechless." At the age of 37, Michelangelo's reputation rose such that he was called "il divino", and he was henceforth regarded as the greatest artist of his time, who had elevated the status of the arts themselves, a recognition that lasted the rest of his long life. The ceiling was immediately considered one of the greatest masterpieces of all time, a distinction which continues to endure.


title: Sistine Chapel ceiling

text: Michelangelo probably began working on the plans and sketches for the design from April 1508. The preparatory work on the ceiling was complete in late July the same year and on 4 February 1510, Francesco Albertini recorded that Michelangelo had "decorated the upper, arched part with very beautiful pictures and gold". The main design was largely finished in August 1510, as Michelangelo's texts suggest. From September 1510 until February, June, or September 1511, Michelangelo did no work on the ceiling on account of a dispute over payments for work done; in August 1510 the pope left Rome for the Papal States' campaign to reconquer Bologna and despite two visits there by Michelangelo, resolution only came months after the pope's return to Rome in June 1511. On 14 August 1511, Julius held a papal mass in the chapel and saw the progress of the work so far for the first time. This was the vigil for Assumption Day on 15 August, the Sistine Chapel's patronal feast. The whole design was revealed to visitors on 31 October 1512 with a formal papal mass the following day, the feast of All Saints. Clerical use of the chapel continued throughout, exempting when the work on the scaffolding necessitated its closure, and disruption to the rites was minimized by beginning the work at the west end, furthest from the liturgical centre around the altar at the east wall. Debate exists on what sequence the parts of the ceiling were painted in and over how the scaffold that allowed the artists to reach the ceiling was arranged. There are two main proposals.


title: Sistine Chapel ceiling

text: The majority theory is that the ceiling's main frescoes were applied and painted in phases, with the scaffolding each time dismantled and moved to another part of the room, beginning at the chapel's west end. The first phase, including the central life of Noah, was completed in September 1509 and the scaffolding removed; only then were the scenes visible from the floor level. The next phase, in the middle of the chapel, completed the "Creation of Eve" and the "Fall and Expulsion from Paradise". The "Cumaean Sibyl" and "Ezekiel" were also painted in this phase. Michelangelo painted the figures at a larger scale than in the previous section; this is attributed to the artist's ability to effectively judge the foreshortening and composition from ground level for the first time. The figures of the third phase, at the east end, were at still grander scale than the second; "The Creation of Adam" and the other "Creation" panels were finished at this stage, which took place in 1511. The lunettes above the windows were painted last, using a small movable scaffold. In this scheme, proposed by Johannes Wilde, the vault's first and second registers, above and below the fictive architectural cornice, were painted together in stages as the scaffolding moved eastwards, with a stylistic and chronological break westwards and eastwards of the "Creation of Eve". After the central vault the main scaffold was replaced by a smaller contraption that allowed the painting of the lunettes, window vaults, and pendentives. This view supplanted an older view that the central vault formed the first part of the work and was completed before work began on the other parts of Michelangelo's plan.


title: Sistine Chapel ceiling

text: Another theory is that the scaffolding must have spanned the entire chapel for years at a time. To remove the existing decoration of the ceiling, the entire area had to be accessible for workmen to chisel away the starry-sky fresco before any new work was done. On 10 June 1508, the cardinals complained of the intolerable dust and noise generated by the work; by 27 July 1508, the process was complete and the corner spandrels of the chapel had been converted into the doubled-spandrel triangular pendentives of the finished design. Then the frame of the new designs had to be marked out on the surface when frescoeing began; this too demanded access to the whole ceiling. This thesis is supported by the discovery during the modern restoration of the exact numbers of the "giornate" employed in the frescoes; if the ceiling was painted in two stages, the first spanning two years and extending to the "Creation of Eve" and the second lasting just one year, then Michelangelo would have to have painted 270 "giornate" in the yearlong second phase, compared with 300 painted in the first two years, which is scarcely possible. By contrast, if the ceiling's first registerwith the nine scenes on rectangular fields, the medallions, and the "ignudi"was painted in the first two years, and in the second phase, Michelangelo painted only their border in the second register with the "Prophets" and "Sibyls", then the "giornate" finished in each year are divided almost equally. Ulrich Pfisterer, advancing this theory, interprets Albertini's remark on "the upper, arched part with very beautiful pictures and gold" in February 1510 as referring only to the upper part of the vaultthe first register with its nine picture fields, its "gnudi," and its medallions embellished with goldand not to the vault as a whole since the fictive architectural attic with its prophets and prophetesses were yet to be started.


title: Sistine Chapel ceiling

text: The scaffolding needed to protect the chapel's existing wall frescoes and other decorations from falling debris and allow the religious services to continue below, but also to allow in air and some light from the windows below. The chapel's cornice, running around the room below the lunettes at the springing of the window arches themselves, supported the structure's oblique beams, while the carrying beams were set into the wall above the cornice using putlog holes. This open structure supported catwalks and the movable working platform itself, whose likely stepped design followed the contour of the vault. Beneath was a false ceiling that protected the chapel. Though some sunlight would have entered the workspace between the ceiling and the scaffolding, artificial light would have been required for painting, candlelight possibly influencing the appearance of the vivid colors used.


title: Sistine Chapel ceiling

text: Restoration overseer Fabrizio Mancinelli speculates that Michelangelo may have only installed scaffolding platforms in one half of the room at a time to cut the cost of timber and to allow light to pass through the uncovered windows. The areas of the wall covered by the scaffolding still appear as unpainted areas at the base of the lunettes.


title: Sistine Chapel ceiling

text: The entire ceiling is a fresco, which is an ancient method for painting murals that relies upon a chemical reaction between damp lime plaster and water-based pigments to permanently fuse the work into the wall. Michelangelo had been an apprentice in the workshop of Domenico Ghirlandaio, one of the most competent and prolific of Florentine fresco painters, at the time that the latter was employed on a fresco cycle at Santa Maria Novella and whose work was represented on the walls of the Sistine Chapel. At the outset, the plaster, "intonaco", began to grow mildew or mould because it was too wet. When Michelangelo despaired of continuing, the pope sent Giuliano da Sangallo, who explained how to remove the fungus.


title: Sistine Chapel ceiling

text: Because Michelangelo was painting "alfresco", the plaster was laid in a new section every day, called a "giornata". At the beginning of each session, the edges would be scraped away and a new area laid down.


title: Sistine Chapel ceiling

text: The work commenced at the end of the building furthest from the altar with the last chronological part of the narrative and progressed towards the altar with the scenes of the Creation. The first three scenes, from "The Drunkenness of Noah", contain crowded compositions of smaller figures than other panels, evidently, because Michelangelo misjudged the ceiling's size. Also painted in the early stages was the "Slaying of Goliath". After painting the "Creation of Eve" adjacent to the marble screen which divided the chapel, Michelangelo paused in his work to move the scaffolding to the other side. After having seen his completed work so far, he returned to work with the "Temptation and Fall", followed by the "Creation of Adam". As the scale of the work got larger, Michelangelo's style became broader; the final narrative scene of God in the act of creation was painted in a single day.


title: Sistine Chapel ceiling

text: According to Vasari, the ceiling was unveiled before it could be reworked with "a secco" and gold to give it "a finer appearance" as had been done with the chapel's wall frescoes. Both Michelangelo and Pope Julius II wanted these details to be added, but this never took place, in part because Michelangelo did not want to rebuild the scaffolding; he also argued that "in those days men did not wear gold, and those who are painted ... were holy men who despised wealth." Julius II died only months after the ceiling's completion, in February 1513.


title: Sistine Chapel ceiling

text: According to Vasari and Condivi, Michelangelo painted in a standing position, not lying on his back, as another biographer, Paolo Giovio, imagined. Vasari wrote: "These frescos were done with the greatest discomfort, for he had to stand there working with his head tilted backwards." Michelangelo may have described his physical discomfort in a poem, accompanied by a sketch in the margin, which was probably addressed to the humanist academician Giovanni di Benedetto da Pistoia, a friend with whom Michelangelo corresponded. Leonard Barkan compared the posture of Michelangelo's marginalia self-portrait to the Roman sculptures of "Marsyas Bound" in the Uffizi Gallery; Barkan further connects the flayed Marsyas with Michelangelo's purported self-portrait decades later on the flayed skin of St Bartholomew in his "Last Judgment" but cautions that there is no certainty the sketch represents the process of painting the chapel ceiling. Michelangelo wrote a poem describing the arduous conditions under which he worked. The manuscript is illustrated with a sketch of the poet painting the ceiling.


title: Sistine Chapel ceiling

text: Michelangelo's frescoes form the backstory to the 15th-century narrative cycles of the lives of Moses and Jesus Christ by Perugino and Botticelli on the chapel's walls. While the main central scenes depict incidents in the Book of Genesis, the first book of the Bible, much debate exists on the multitudes of figures' exact interpretation. The Sistine Chapel's ceiling is a shallow barrel vault around 35 metres (118 feet) long and around 14 m (46 ft) broad. The chapel's windows cut into the vault's curve, producing a row of lunettes alternating with spandrels.


title: Sistine Chapel ceiling

text: Though Michelangelo claimed he eventually had a free hand in the artistic scheme, this claim was also made by Lorenzo Ghiberti about his monumental bronze doors for the Florence Baptistery, for which it is known Ghiberti was constrained by stipulations on how the Old Testament scenes should appear and was able to decide merely the forms and number of the picture fields. It is likely that Michelangelo was free to choose forms and presentation of the design, but that the subjects and themes themselves were decided by the patron.


title: Sistine Chapel ceiling

text: The central, almost flat field of the ceiling is delineated by a fictive architectural cornice and divided into four large rectangles and five smaller ones by five pairs of painted ribs which cut laterally across the central rectangular field. These rectangles, which appear open to the sky, Michelangelo painted with scenes from the Old Testament.


title: Sistine Chapel ceiling

text: The narrative begins at the chapel's east end, with the first scene above the altar, focus of the Eucharistic ceremonies performed by the clergy. The small rectangular field directly above the altar depicts the "Primal Act of Creation". The last of the nine central fields, at the west end, shows the "Drunkenness of Noah"; below this scene is the door used by the laity. Furthest from the altar, the "Drunkenness of Noah" represents the sinful nature of man.


title: Sistine Chapel ceiling

text: Above the cornice, at the four corners of each of the five smaller central fields, are nude male youths, called "ignudi", whose precise significance is unknown. Close to the sacred scenes in the uppermost register and unlike the figures of the lower register shown in perspective, they are not foreshortened. They probably represent the Florentine Neoplatonists' view of humanity's ideal Platonic form, without the mar of Original Sin, to which the lower figures are all subject. Kenneth Clark wrote that "their physical beauty is an image of divine perfection; their alert and vigorous movements an expression of divine energy".


title: Sistine Chapel ceiling

text: Below the painted cornice around the central rectangular area is a lower register depicting a continuation of the chapel's walls as a trompe-l'œil architectural framework against which figures press, with powerful modelling. The figures are drastically foreshortened and are at larger scale than the figures in the central scenes, which according to Harold Osborne and Hugh Brigstocke creates "a sense of spatial disequilibrium".


title: Sistine Chapel ceiling

text: The ceiling at the chapel's four corners forms a doubled spandrel painted with salvific scenes from the Old Testament: "The Brazen Serpent", "The Crucifixion of Haman", "Judith and Holofernes", and "David and Goliath".


title: Sistine Chapel ceiling

text: On the crescent-shaped areas, or lunettes, above each of the chapel's windows are tablets listing the ancestors of Christ and accompanying figures. Above them, in the triangular spandrels, a further eight groups of figures are shown, but these have not been identified with specific biblical characters. The scheme is completed by four large corner pendentives, each illustrating a dramatic biblical story.


title: Sistine Chapel ceiling

text: Each of the chapel's window arches cuts into the curved vault, creating above each a triangular area of vaulting. The arch of each window is separated from the next by these triangular spandrels, in each of which are enthroned "Prophets" alternating with the "Sibyls". These figures, seven Old Testament prophets and five of the Graeco-Roman sibyls, were notable in Christian tradition for their prophesies of the Messiah or the Nativity of Jesus. The lunettes above the windows are themselves painted with scenes of the "purely human" "Ancestors of Christ", as are the spaces either side of each window. Their position is both the lowest in the vault and the darkest, in contrast with the airy upper vault.


title: Sistine Chapel ceiling

text: The overt subject matter of the ceiling is the Christian doctrine of humanity's need for salvation as offered by God through Jesus. It is a visual metaphor of humankind's need for a covenant with God. The Old Covenant of the Children of Israel through Moses and the New Covenant through Christ had already been represented around the walls of the chapel. Some experts, including Benjamin Blech and Vatican art historian Enrico Bruschini, have also noted less overt subject matter, which they describe as being "concealed" and "forbidden."


title: Sistine Chapel ceiling

text: The main scheme of the ceiling illustrates God creating the perfect world prior to creating humanity, which causes its own fall into disgrace and is punished by being made mortal; humanity then sinks further into sin and disgrace, and is punished by the Great Flood. The ceiling's creation narrative ends with Noah's drunkenness, which Jesuit theologian John W. O'Malley says could be interpreted as focusing on the separation of Gentiles from Jews as the chosen people. Then, through a lineage of ancestorsfrom Abraham to JosephGod sends the saviour of humanity, Jesus, whose coming is claimed in the New Testament to have been prophesied by prophets of Israel (to whom Michelangelo adds sibyls of the Classical world) and whose second coming the same artist returned to paint on the altar wall in his "Last Judgment". The prophet Jonah, recognizable over the altar by the great fish beside him, is cited by Jesus in the gospels as being related to his own coming death and resurrection, which Staale Sinding-Larsen says "activates the Passion motif". In the Gospel of John, moreover, Jesus compares his being raised (i.e. his crucifixion) to Moses lifting the Brazen Serpent to heal Israelites from fiery serpent bites; the latter is painted on the pendentive above the altar to the left, opposite the "Punishment of Haman", depicted as a crucifixion instead of a hanging.


title: Sistine Chapel ceiling

text: Of the three Twelve Minor Prophets depicted on the ceiling, O'Malley discusses Jonah and Zechariah as carrying a particular significance. In addition to Jonah's connection to Jesus, O'Malley points out that he is a spokesman to the Gentiles. Zechariah prophesied that the Messiah would arrive on a donkey. His place in the chapel is directly above the doorway across from the altar, through which the pope is carried in procession on Palm Sunday, the day on which Jesus rode a donkey into Jerusalem.


title: Sistine Chapel ceiling

text: Much of the symbolism of the ceiling dates from the early church, but the ceiling also has elements that express the specifically Renaissance thinking that sought to reconcile Christian theology with the philosophy of Renaissance humanism. During the 15th century in Italy, and in Florence in particular, there was a strong interest in Classical literature and the philosophies of Plato, Aristotle and other Classical writers. Michelangelo, as a young man, had spent time at the Platonic Academy established by the Medici family in Florence. He was familiar with early humanist-inspired sculptural works such as Donatello's bronze "David" and had himself responded by carving the enormous nude marble "David", which was placed in the Piazza Della Signoria near the Palazzo Vecchio, the home of Florence's council. The humanist view of spirituality was that it is rooted in human nature and independent from intermediaries such as the Church, which emphasized humanity as essentially sinful and flawed. A synthesis, with man dignified and created in God's image, was epitomized by Giovanni Pico Della Mirandola's "Oration on the Dignity of Man", which was referenced in sermons given at the papal court.


title: Sistine Chapel ceiling

text: The iconography of the ceiling has had various interpretations in the past, some elements of which have been contradicted by modern scholarship. Others, such as the identity of the figures in the lunettes and spandrels poppets, continue to defy interpretation. Modern scholars have sought, as yet unsuccessfully, to determine a written source of the theological program of the ceiling and have questioned whether or not it was entirely devised by Michelangelo, who was both an avid reader of the Bible and is considered to be a genius. Art historian Anthony Bertram argues that the artist expressed his inner turmoil in the work, saying: "The principal opposed forces in this conflict were his passionate admiration for classical beauty and his profound, almost mystical Catholicism, his [presumed] homosexuality, and his horror of carnal sin combined with a lofty Platonic concept of love."


title: Sistine Chapel ceiling

text: Edgar Wind postulated that the ten medallions represented violations of the Ten Commandments, with the obscured one above the Persian Sibyl standing for adultery. O'Malley points out that, if this is the case, the infractions of the commandments are arranged out of order.


title: Sistine Chapel ceiling

text: The Sistine Chapel is about 35 m (118 ft) long and wide, with the ceiling rising to about above the main floor. The vault is of quite a complex design and it is unlikely that it was originally intended to have such elaborate decoration.


title: Sistine Chapel ceiling

text: The chapel walls have three horizontal tiers with six windows in the upper tier down each side. There were also two windows at each end, but these have been closed up above the altar when Michelangelo's "Last Judgment" was painted, obliterating two lunettes. Between the windows are large pendentives which support the vault. Between the pendentives are triangularly shaped arches or spandrels cut into the vault above each window. Above the height of the pendentives, the ceiling slopes gently without much deviation from the horizontal.


title: Sistine Chapel ceiling

text: The first element in the scheme of painted architecture is a definition of the "real" architectural elements by accentuating the lines where spandrels and pendentives intersect with the curving vault. Michelangelo painted these as decorative courses that look like sculpted stone mouldings. These have two repeating motifs, a formula common in Classical architecture. Here, one motif is the acorn, the symbol of the family of both Pope Sixtus IV, who built the chapel, and Pope Julius II, who commissioned Michelangelo's work. The other motif is the scallop shell, one of the symbols of the Madonna, to whose Assumption the chapel was dedicated in 1483. The crown of the wall then rises above the spandrels, to a strongly projecting painted cornice that runs right around the ceiling, separating the pictorial areas of the biblical scenes from the figures of prophets, sibyls, and ancestors, who literally and figuratively support the narratives. Ten broad painted cross-ribs of travertine cross the ceiling and divide it into alternately wide and narrow pictorial spaces, a grid that gives all the figures their defined place.


title: Sistine Chapel ceiling

text: A great number of small figures are integrated with the painted architecture, their purpose apparently purely decorative. These include pilasters with capitals supported by pairs of infant "telamones," rams' skulls are placed at the apex of each spandrel like "bucrania"; bronze nude figures in varying poses, hiding in the shadows, propped between the spandrels and the ribs like animated bookends; and more "putti", both clothed and unclothed, strike a variety of poses as they support the nameplates of the "Prophets and Sibyls". Above the cornice and to either side of the smaller scenes are an array of medallions, or round shields. They are framed by a total of 20 more figures, the so-called "ignudi", which are not part of the architecture but sit on plinths, their feet planted convincingly on the fictive cornice. Pictorially, the "ignudi" appear to occupy a space between the narrative spaces and the space of the chapel itself.


title: Sistine Chapel ceiling

text: Along the central section of the ceiling, Michelangelo depicted nine scenes from the Book of Genesis, organized into three groups of three related scenes. The scenes alternate between smaller and larger pictures, with the former framed by two pairs of "ignudi" flanking a medallion.


title: Sistine Chapel ceiling

text: The first group depicts God creating the Heavens and the Earth. The second group shows God creating the first man and woman, Adam and Eve, and their disobedience of God and consequent expulsion from the Garden of Eden. The third group shows the plight of humanity and in particular the family of Noah.


title: Sistine Chapel ceiling

text: The pictures within the three groups link to one another, in the same way as was usual in Mediaeval paintings and stained glass. The nine scenes are oriented to be viewed while facing the altar, chronologically unfolding towards the chapel entrance (except for the second and third scenes, and the seventh and eighth, which are each transposed). John T. Paoletti and Gary M. Radke suggest that this reversed progression symbolises a return to a state of grace.


title: Sistine Chapel ceiling

text: The three creation pictures show scenes from the first chapter of Genesis, which relates that God created the Earth and its inhabitants in six days, resting on the seventh day. In the first scene, the "First Day of Creation", God creates light and separates light from darkness. Chronologically, the next scene takes place in the third panel, in which, on the "Second Day", God divides the waters from the heavens. In the central scene, the largest of the three, there are two representations of God: on the "Third Day", God creates the Earth and makes it sprout plants; on the "Fourth Day", God puts the Sun and the Moon in place to govern the night and the day, the time and the seasons of the year.


title: Sistine Chapel ceiling

text: These three scenes, completed in the third stage of painting, are the most broadly conceived, the most broadly painted and the most dynamic of all the pictures. Of the first scene Vasari says, "Michelangelo depicted God dividing the light from the darkness ... where He is seen in all His majesty as He sustains Himself alone with open arms in a demonstration of love and creative energy."


title: Sistine Chapel ceiling

text: For the central section of the ceiling, Michelangelo took four episodes from the story of Adam and Eve as told in the first, second and third chapters of Genesis. In this sequence of three, two of the panels are large and one small.


title: Sistine Chapel ceiling

text: In the first of the pictures, one of the most widely recognized images in the history of painting, Michelangelo shows God reaching out to touch Adam. Vasari describes Adam as "a figure whose beauty, pose, and contours are of such a quality that he seems newly created by his Supreme and First Creator rather than by the brush and design of a mere mortal." From beneath the sheltering arm of God, Eve looks out somewhat apprehensively. Correspondingly, Adam reaches out to the creator, who Walter Pater states "comes with the forms of things to be, woman and her progeny, in the fold of his garment". Pater wrote of the depiction of Adam in the "Creation":


title: Sistine Chapel ceiling

text: The central scene, of God creating Eve from the side of the sleeping Adam has been taken in its composition directly from another creation sequence, the relief panels that surround the door of the Basilica of San Petronio, Bologna, by Jacopo della Quercia, whose work Michelangelo had studied in his youth.


title: Sistine Chapel ceiling

text: In the final panel of this sequence, Michelangelo combines two contrasting scenes into one panel, that of Adam and Eve taking fruit from the forbidden tree (a fig and not an apple tree as commonly depicted in Western Christian art), Eve trustingly taking it from the hand of the Serpent (depicted as Lilith) and Adam eagerly picking it for himself, as well as their banishment from the Garden of Eden, where they have lived in the company of God, to the world outside where they have to fend for themselves and experience death.


title: Sistine Chapel ceiling

text: As with the first sequence of pictures, the three panels concerning Noah, taken from the sixth to ninth chapters of Genesis are thematic rather than chronological. In the first scene is shown the sacrifice of a sheep. Both Vasari and Condivi mistake this scene for the sacrifices by Cain and Abel, in which Abel's sacrifice was acceptable to God and Cain's was not. What this image almost certainly depicts is the sacrifice made by the family of Noah, after their safe deliverance from the Great Flood which destroyed the rest of humanity.


title: Sistine Chapel ceiling

text: The central, larger, scene shows the Great Flood. The Ark in which Noah's family escaped floats at the rear of the picture while the rest of humanity tries frantically to scramble to some point of safety.


title: Sistine Chapel ceiling

text: The final scene is the story of Noah's drunkenness. After the Flood, Noah tills the soil and grows vines. He is shown doing so in the background of the picture. He becomes drunk and inadvertently exposes himself. His youngest son, Ham, brings his two brothers Shem and Japheth to see the sight but they discreetly cover their father with a cloak. Ham is later cursed by Noah and told that the descendants of Ham's son Canaan will serve Shem and Japheth's descendants forever.


title: Sistine Chapel ceiling

text: Since Michelangelo executed the nine biblical scenes in reverse chronological order, some analyses of the frescoes of the vault commence with the "Drunkenness of Noah". Charles de Tolnay's neoplatonic interpretation sees the story of Noah at the beginning and the act of creation by God as the conclusion of the process of "deificatio" and the return from physical to spiritual being.


title: Sistine Chapel ceiling

text: Adjacent to the smaller biblical scenes in the first register and supported by the paired "ignudi" are ten medallions. In four of the five most highly finished, the space is crowded with figures in violent action, similar to Michelangelo's cartoon for the "Battle of Cascina". The subjects depicted are somewhat ambiguous, with Vasari merely saying they are taken from the Book of Kings. According to Ulrich Pfisterer, Michelangelo adapted the medallions from woodcut illustrations in the 1490 Malermi Bible, the first Italian-language Bible, named after its translator, Nicolò Malermi. The medallions have been interpreted as depicting:


title: Sistine Chapel ceiling

text: On the five pendentives along each side and the two at either end, Michelangelo painted the largest figures on the ceiling: twelve people who prophesied a Messiah. These twelve are seven male prophets of Israel and five "Sibyls," prophetesses of classical mythology. "Jonah" is placed above the altar and "Zechariah" at the opposite end. The other five "Prophets" and "Sibyls" alternate down each long side, each being identified by an inscription on a painted marble tablet supported by a "putto".


title: Sistine Chapel ceiling

text: Seven prophets of Israel are depicted on the ceiling, including the four so-called major prophetsIsaiah, Jeremiah, Ezekiel, and Danieland three of the Twelve Minor Prophets: Joel, Zechariah, and Jonah.


title: Sistine Chapel ceiling

text: The Book of Joel prophesies the triumph of Judah over its enemies, and includes the words, "Your sons and your daughters shall prophesy, your old men shall dream dreams [and] your young men shall see visions." Zechariah was the first "Prophet" to be painted.


title: Sistine Chapel ceiling

text: Condivi praises "Jonah", including its foreshortening. In Vasari's description of the "Prophets and Sibyls" he is particularly high in his praise of "Isaiah", saying, "anyone who examines this figure will see details taken from Nature herself, the true mother of the art of painting, and will see a figure that with close study can in broad terms teach all the precepts of good painting."


title: Sistine Chapel ceiling

text: The Sibyls were prophetic women who were resident at shrines or temples throughout the Classical world. The papal court generally regarded antiquity as setting the stage for Christianity. For example, the Cumaean Sibyl is quoted by 1st-century BC Roman poet Virgil in his Fourth "Eclogue" as declaring that "a new progeny of Heaven" would bring about a return of the "Golden Age". Many people during the Renaissance interpreted this as foretelling the birth of Jesus.


title: Sistine Chapel ceiling

text: There was an increasing interest in the remains of Rome's pagan past within the Catholic Church; scholars had turned from reading Mediaeval ecclesiastical Latin texts to classical Latin and the philosophies of the Classical world were studied along with the writings of St Augustine. Thus, the presence of five pagan prophets in the Sistine Chapel is not surprising.


title: Sistine Chapel ceiling

text: It is not known why Michelangelo selected the five particular Sibyls that were depicted, given that there were ten possibilities. O'Malley suggests that the four besides the Cumaean Sibyl were selected for a wide geographic coverage, as they come from Africa, Asia, Greece and Ionia.


title: Sistine Chapel ceiling

text: Vasari says of the "Erythraean Sibyl": "This figure is extraordinarily beautiful owing to the expression of its face, the arrangement of its hair, and the style of its garments, not to mention its bare arms, which are as beautiful as the rest of the body."


title: Sistine Chapel ceiling

text: In each corner of the chapel is a triangular pendentive filling the space between the walls and the arch of the vault and forming a doubled spandrel above the windows nearest the corners. On these curving shapes Michelangelo has painted four scenes from biblical stories that are associated with the salvation of Israel by four great male and female heroes of the Jews: Moses, Esther, David and Judith. The first two stories were both seen in Mediaeval and Renaissance theology as prefiguring the Crucifixion of Jesus. The other two stories, those of David and Judith, were often linked in Renaissance art, particularly by Florentine artists as they demonstrated the overthrow of tyrants, a popular subject in the Republic.


title: Sistine Chapel ceiling

text: In the Book of Esther, it is related that Haman, a public servant, plots to get Esther's husband, the king of Persia, to slay all the Jewish people in his land. The king, who is going over his books during a sleepless night, realizes something is amiss. Esther, discovering the plot, denounces Haman, and her husband orders his execution on a scaffold he has built. The king's eunuchs promptly carry this out. Michelangelo shows Haman crucified (instead of hung as in the original story) with Esther looking at him from a doorway and the king giving orders in the background. The composition shows Haman at the table with Esther, as well as being crucified. Mordechai sits on the steps, linking the scenes.


title: Sistine Chapel ceiling

text: In the story of the Brazen Serpent, the people of Israel become dissatisfied and grumble at God. As punishment, they receive a plague of venomous snakes. God offers the people relief by instructing Moses to make a snake of brass and set it up on a pole, the sight of which gives miraculous healing. The composition is crowded with figures and separate incidents as the various individuals who have been attacked by snakes struggle and die or turn toward the icon that will save them. This is the most Mannerist of Michelangelo's earlier compositions at the chapel.


title: Sistine Chapel ceiling

text: Writing in the 19th century, English art critic John Ruskin compares "The Brazen Serpent" favourably to the canonical classical statue group "Laocoön and His Sons", which Michelangelo saw upon its discovery in 1506. Both works are crowded compositions of figures attacked by supernatural reptiles: the "fiery serpents" of the book of Numbers and the sea monsters of Virgil's "Aeneid". Ruskin states that he prefers the sublimity expressed by Michelangelo's "gigantic intellect" in "the grandeur of the plague itself, in its multitudinous grasp, and its mystical salvation" and his "awfulness and quietness" to the "meagre lines and contemptible tortures of the Laocoön" and argued that "the grandeur of this treatment results, not merely from choice, but from a greater knowledge and more faithful rendering of truth". Attacking the sculpture's unnaturalistic snakes as "pieces of tape with heads to them" and criticizing the unrealistic struggle, he praises the painting


title: Sistine Chapel ceiling

text: "Judith and Holofernes" depicts the episode in the "Book of Judith". As Judith loads the enemy's head onto a basket carried by her maid and covers it with a cloth, she looks towards the tent, apparently distracted by the limbs of the decapitated corpse flailing about. The composition is vertically split, not unlike the "Punishment of Haman" at the opposite corner of the chapel.


title: Sistine Chapel ceiling

text: In "David and Goliath", the shepherd boy, David, has brought down the towering Goliath with his sling, but the giant is alive and is trying to rise as David forces his head down to chop it off.


title: Sistine Chapel ceiling

text: "David and Goliath" is a relatively simple composition, with the two protagonists centrally placed and the only other figures being background observers.


title: Sistine Chapel ceiling

text: Either side of the chapel has six windows, as well as two closed windows at the rear, and two above the altar which were covered by "The Last Judgment". Above each window is an arched shape, referred to as a lunette. Above each of the eight most central side lunettes is a triangular spandrel (topped by symmetrical pairs of bronze nudes); the other six lunettes are below the corner pendentives.


title: Sistine Chapel ceiling

text: These regions link the walls and the ceiling; the figures painted on them are intermediate in size (approximately 2 m tall), between the very large prophets on the ceiling and the much smaller papal portraits which had been painted on either side of each window in the 15th century. Michelangelo chose the ancestors of Christ as the subject of these images, thus juxtaposing Jesus' physical lineage with the popes, his spiritual successors according to the Church.


title: Sistine Chapel ceiling

text: Centrally placed above each window is a "faux" marble tablet with a decorative frame. On each is painted the names of the male line by which Jesus, through his earthly father, Joseph, is descended from Abraham, according to the Gospel of Matthew. However, the genealogy is now incomplete, since the two lunettes of the windows in the altar wall were destroyed by Michelangelo when he returned to the chapel in 1537 to paint "The Last Judgment". Only engravings, based on a drawing that has since been lost, remain of them. The sequence of tablets seems somewhat erratic as one plaque has four names, most have three or two, and two plaques have only one. Moreover, the progression moves from one side of the building to the other, but not consistently, and the figures the lunettes contain do not coincide closely with the listed names. These figures vaguely suggest various family relationships; most lunettes contain one or more infants, and many depict a man and a woman, often sitting on opposing sides of the painted plaque that separates them. O'Malley describes them as "simply representative figures, almost ciphers".


title: Sistine Chapel ceiling

text: The figures in the lunettes appear to be families, but in every case they are families that are divided. The figures in them are physically divided by the name tablet but they are also divided by a range of human emotions that turn them outward or in on themselves and sometimes towards their partner with jealousy, suspicion, rage or simply boredom. In them Michelangelo has portrayed the anger and unhappiness of the human condition, painting, in Andrew Graham-Dixon's words, "the daily round of merely domestic life as if it were a curse". In their constraining niches, Gabriele Bartz and Eberhard König say, the ancestors "sit, squat and wait". Of the 14 lunettes, the two that were probably painted first, the families of Eleazar and Mathan and of Jacob and his son Joseph, are the most detailed. They become progressively broader towards the altar end, as Michelangelo painted faster and more furiously.


title: Sistine Chapel ceiling

text: Because of the constraints of the triangular shape, in each spandrel the figures are seated on the ground. Six include groups of figures, mostly adults with a child. Of the two remaining, one shows a woman with shears trimming the neck of a garment she is making while her toddler looks on. The biblical woman who is recorded as making a new garment for her child is Hannah, the mother of Samuel, whose child went to live in the temple; the male figure in the background is wearing a distinctive hat that might suggest that of a priest. Another female figure sits staring out of the picture.


title: Sistine Chapel ceiling

text: Prior to restoration, of all the paintings in the chapel, the lunettes and spandrels were the dirtiest. Added to this, there has always been a problem of poor daytime visibility of the panels nearest the windows because of "halination", the effect of bright areas blurring over less bright ones.


title: Sistine Chapel ceiling

text: The "ignudi" are the 20 athletic, nude males that Michelangelo painted as supporting figures at each corner of the five smaller creation scenes on the ceiling, each pair enclosing a medallion supported by ribands above the "Prophets" and "Sibyls". The figures hold, are draped with, or lean on items like ribbons, pillows, and large garlands of acorns.


title: Sistine Chapel ceiling

text: Some have suggested that the "ignudi" could represent angels, similar to cherubs. O'Malley compares them to sculptures of Atlas or Michelangelo's "Slaves" from Julius II's tomb. In their reflection of classical antiquity they resonate with Pope Julius's aspirations to lead Italy towards a new 'age of gold'; at the same time, they staked Michelangelo's claim to greatness. Contrarily, a number of critics were angered by their presence and nudity, including Pope Adrian VI, who wanted the ceiling stripped.


title: Sistine Chapel ceiling

text: Michelangelo was the artistic heir to the great 15th-century sculptors and painters of Florence. He learned his trade first under the direction of a masterly fresco painter, Domenico Ghirlandaio, known for two great fresco cycles in the Sassetti Chapel and Tornabuoni Chapel, and for his contribution to the cycle of paintings on the walls of the Sistine Chapel. As a student Michelangelo studied and drew from the works of the some of the most renowned Florentine fresco painters of the early Renaissance, including Giotto and perhaps Masaccio. Masaccio's figures of Adam and Eve being expelled from the Garden of Eden had a profound effect on the depiction of the nude in general, and in particular on its use to convey human feeling. Helen Gardner says that in the hands of Michelangelo, "the body is simply the manifestation of the soul, or of a state of mind and character."


title: Sistine Chapel ceiling

text: Michelangelo was also almost certainly influenced by the paintings of Luca Signorelli, whose paintings, particularly the "Death and Resurrection Cycle" in Orvieto Cathedral, contain a great number of nudes and inventive figurative compositions. In Bologna, Michelangelo saw the relief sculptures of Jacopo della Quercia around the "Porta Magna" of the minor basilica. In Michelangelo's depiction of the "Creation of Eve" the whole composition, the form of the figures and the relatively conservative concept of the relationship between Eve and her Creator adheres closely to Jacopo's design. Other panels on the ceiling, most particularly the iconic "Creation of Adam" show what Bartz and König call "unprecedented invention"; the pair call the ceiling in general "an artistic vision without precedent".


title: Sistine Chapel ceiling

text: Older depictions of the creation scenes had depicted God as mostly immobile, a static, enthroned image whose activity was indicated by a gesture of the hand, as in the creation scenes of the mediaeval Byzantine-style mosaics of Monreale Cathedral. Michelangelo, influenced by the "Paradiso" of Dante Alighieri, shows God in full-bodied movement, an innovation Giovanni di Paolo had made in his "Creation and Expulsion from Paradise." Paolo Uccello also had shown some movement in his scene of the creation of Adam and Eve in the cloister of Santa Maria Novella. In di Paolo's painting, as in Michelangelo's fresco, God is accompanied and apparently carried aloft by attendant "putti". Raphael employed movement somewhat more in his contemporary "The Prime Mover", next door to the Sistine Chapel in the s"tanza della segnatura" and painted 1509–11; Perugino's slightly earlier "Creator" in fresco"," in the room named for Raphael's "Incendio del Borgo", shows a seated, static divinity.


title: Sistine Chapel ceiling

text: The Sistine Chapel ceiling was to have a profound effect upon other artists, even before it was completed. Vasari, in his "Life of Raphael", tells us that Bramante, who had the keys to the chapel, let Raphael in to examine the paintings in Michelangelo's absence; on seeing Michelangelo's prophets, Raphael went back to the picture of Isaiah that he was painting on a column in the Church of Sant'Agostino and, although it was finished, he scraped it off the wall and repainted it in a much more powerful manner in imitation of Michelangelo. O'Malley points out that even earlier than the "Isaiah" is Raphael's inclusion of the figure of Heraclitus in the "School of Athens", a brooding figure similar to Michelangelo's "Jeremiah", but with the countenance of Michelangelo himself, and leaning on a block of marble.


title: Sistine Chapel ceiling

text: In January 2007, it was claimed that as many as 10,000 visitors passed through the Vatican Museums in a day, double the quantity of the previous decade.


title: Sistine Chapel ceiling

text: The ceiling had suffered a degree of damage as early as the mid-16th century. In 1797, a gunpowder explosion Castel Sant'Angelo damaged part of the "Flood" fresco and one of the "ignudi" (the latter being preserved by a drawing by a pupil of Michelangelo).


title: Sistine Chapel ceiling

text: Over the centuries after the ceiling's painting, it became so aged by candle smoke and layers of varnish as to significantly mute the original colours. Some restorations took place in the early and mid-20th century. After preliminary tests taking place in 1979, the ceiling was restored between 1980 and 1992.


title: Sistine Chapel ceiling

text: The first stage of restoration, the work upon Michelangelo's lunettes, was performed between June 1980 October 1984. The work then proceeded to the ceiling, completed on 31 December 1989, and from there to "The Last Judgment". The restoration was unveiled by Pope John Paul II on 8 April 1994.


title: Sistine Chapel ceiling

text: The restoration of the ceiling was directed by Fabrizio Mancinelli and performed by Gianluigi Colalucci, Maurizio Rossi, Pier Giorgio Bonetti, and Bruno Baratti.


title: Sistine Chapel ceiling

text: The restoration has removed the filter of grime to reveal colours closer to the paintings at the time of their completion. The ceiling now appears to depict daytime scenes and a springlike atmosphere with bright saturated colours. The restoration was met with both praise and criticism. Critics assert that much original work by Michelangelo – in particular pentimenti, highlights and shadows, and other detailing painted "a secco" – was lost in the removal of various accretions.


title: Sistine Chapel ceiling

text: In 2007, the Vatican, anxious at the possibility that the newly restored frescoes would suffer damage, announced plans to reduce visiting hours and raise the price in an attempt to discourage visitors.


title: Sistine Chapel ceiling

text: The art critic and television producer Waldemar Januszczak wrote that when the Sistine Chapel ceiling was recently cleaned, he "was able to persuade the man at the Vatican who was in charge of Japanese TV access to let me climb the scaffold while the cleaning was in progress."


title: Sistine Chapel ceiling

text: I sneaked up there a few times. And under the bright, unforgiving lights of television, I was able to encounter the real Michelangelo. I was so close to him I could see the bristles from his brushes caught in the paint; and the mucky thumbprints he'd left along his margins. The first thing that impressed me was his speed. Michelangelo worked at Schumacher pace. ... I also enjoyed his sense of humour, which, from close up, turned out to be refreshingly puerile. If you look closely at the angels who attend the scary prophetess on the Sistine ceiling known as the Cumaean Sibyl, you will see that one of them has stuck his thumb between his fingers in that mysteriously obscene gesture that visiting fans are still treated to today at Italian football matches.


The United States Department of Homeland Security (DHS) is the U.S. federal executive department responsible for public security, roughly comparable to the interior or home ministries of other countries. Its stated missions involve anti-terrorism, border security, immigration and customs, cyber security, and disaster prevention and management.


title: United States Department of Homeland Security

text: It began operations in 2003, formed as a result of the Homeland Security Act of 2002, enacted in response to the September 11 attacks. With more than 240,000 employees, DHS is the third-largest Cabinet department, after the Departments of Defense and Veterans Affairs. Homeland security policy is coordinated at the White House by the Homeland Security Council. Other agencies with significant homeland security responsibilities include the Departments of Health and Human Services, Justice, and Energy.


text: In response to the September 11 attacks, President George W. Bush announced the establishment of the Office of Homeland Security (OHS) to coordinate "homeland security" efforts. The office was headed by former Pennsylvania Governor Tom Ridge, who assumed the title of Assistant to the President for Homeland Security. The official announcement states:


text: Ridge began his duties as OHS director on October 8, 2001. On November 25, 2002, the Homeland Security Act established the Department of Homeland Security to consolidate U.S. executive branch organizations related to "homeland security" into a single Cabinet agency. The Gilmore Commission, supported by much of Congress and John Bolton, helped further solidify need for the department. The DHS incorporated the following 22 agencies.


text: According to political scientist Peter Andreas, the creation of DHS constituted the most significant government reorganization since the Cold War and the most substantial reorganization of federal agencies since the National Security Act of 1947 (which had placed the different military departments under a secretary of defense and created the National Security Council and Central Intelligence Agency). DHS constitutes the most diverse merger of federal functions and responsibilities, incorporating 22 government agencies into a single organization. The founding of the DHS marked a change in American thought towards threats.


text: Introducing the term "homeland" centers attention on a population that needs to be protected not only against emergencies such as natural disasters but also against diffuse threats from individuals who are non-native to the United States.


text: Prior to the signing of the bill, controversy about its adoption was focused on whether the Federal Bureau of Investigation and the Central Intelligence Agency should be incorporated in part or in whole (neither were included). The bill was also controversial for the presence of unrelated "riders", as well as for eliminating certain union-friendly civil service and labor protections for department employees. Without these protections, employees could be expeditiously reassigned or dismissed on grounds of security, incompetence or insubordination, and DHS would not be required to notify their union representatives. The plan stripped 180,000 government employees of their union rights. In 2002, Bush officials argued that the September 11 attacks made the proposed elimination of employee protections imperative.


text: Congress ultimately passed the Homeland Security Act of 2002, and President Bush signed the bill into law on November 25, 2002. It was the largest U.S. government reorganization in the 50 years since the United States Department of Defense was created.


text: Tom Ridge was named secretary on January 24, 2003, and began naming his chief deputies. DHS officially began operations on January 24, 2003, but most of the department's component agencies were not transferred into the new department until March 1.


text: After establishing the basic structure of DHS and working to integrate its components, Ridge announced his resignation on November 30, 2004, following the re-election of President Bush. Bush initially nominated former New York City Police Department commissioner Bernard Kerik as his successor, but on December 10, Kerik withdrew his nomination, citing personal reasons and saying it "would not be in the best interests" of the country for him to pursue the post.


text: On January 11, 2005, President Bush nominated federal judge Michael Chertoff to succeed Ridge. Chertoff was confirmed on February 15, 2005, by a vote of 98–0 in the U.S. Senate and was sworn in the same day.


text: In February 2005, DHS and the Office of Personnel Management issued rules relating to employee pay and discipline for a new personnel system named MaxHR. "The Washington Post" said that the rules would allow DHS "to override any provision in a union contract by issuing a department-wide directive" and would make it "difficult, if not impossible, for unions to negotiate over arrangements for staffing, deployments, technology and other workplace matters". In August 2005, U.S. District Judge Rosemary M. Collyer blocked the plan on the grounds that it did not ensure collective-bargaining rights for DHS employees. A federal appeals court ruled against DHS in 2006; pending a final resolution to the litigation, Congress's fiscal year 2008 appropriations bill for DHS provided no funding for the proposed new personnel system.


text: DHS announced in early 2007 that it was retooling its pay and performance system and retiring the name "MaxHR". In a February 2008 court filing, DHS said that it would no longer pursue the new rules, and that it would abide by the existing civil service labor-management procedures. A federal court issued an order closing the case.