title: Hot air balloon

text: A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries passengers and a source of heat, in most cases an open flame caused by burning liquid propane. The heated air inside the envelope makes it buoyant, since it has a lower density than the colder air outside the envelope. As with all aircraft, hot air balloons cannot fly beyond the atmosphere. The envelope does not have to be sealed at the bottom, since the air inside the envelope is at about the same pressure as the surrounding air. In modern sport balloons the envelope is generally made from nylon fabric, and the inlet of the balloon (closest to the burner flame) is made from a fire-resistant material such as Nomex. Modern balloons have been made in many shapes, such as rocket ships and the shapes of various commercial products, though the traditional shape is used for most non-commercial and many commercial applications.


title: Hot air balloon

text: The hot air balloon is the first successful human-carrying flight technology. The first untethered manned hot air balloon flight was performed by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes on November 21, 1783, in Paris, France, in a balloon created by the Montgolfier brothers. The first hot air balloon flown in the Americas was launched from the Walnut Street Jail in Philadelphia on January 9, 1793, by the French aeronaut Jean Pierre Blanchard. Hot air balloons that can be propelled through the air rather than simply drifting with the wind are known as thermal airships.


title: Hot air balloon

text: A precursor of the hot air balloon was the sky lantern (). Zhuge Liang of the Shu Han kingdom, during the Three Kingdoms era (220–280 CE), used these airborne lanterns for military signaling.


title: Hot air balloon

text: In the 18th century the Portuguese Jesuit priest Bartolomeu de Gusmão envisioned an aerial apparatus called , which was the predecessor of the hot air balloon. The purpose of was to serve as air vessel in order to facilitate communication and as a strategical device. In 1709 John V of Portugal decided to fund Bartolomeu de Gusmão's project following a petition made by the Jesuit priest, and an unmanned demonstration was performed at Casa da India in presence of John V, the queen Maria Anna of Austria, having as witnesses the Italian cardinal Michelangelo Conti, two members of the Portuguese Royal Academy of History, one Portuguese diplomat and one chronicler. This event would bring some European attention to this event and this project. A later article dated on October 20, 1786, by the London "Daily Universal Register" would state that the inventor was able to raise himself by the use of his prototype. Also in 1709, the Portuguese Jesuit wrote ("Short Manifesto for those who are unaware that is possible to sail through the element air"); he also left designs for a manned air vessel.


title: Hot air balloon

text: The notable balloonist Julian Nott, in the 1970s; hypothesized that two millennia ago, the Nazca Lines geoglyphs' creation could have been guided by Nazca leaders in a balloon, possibly the earliest hot air balloon flights in human history. In 1975 to support this theory, he designed and piloted the Nazca Prehistoric Balloon, claiming to have used only methods and materials available to the Pre-Inca Peruvians 1,000 years ago.


title: Hot air balloon

text: The French brothers Joseph-Michel and Jacques-Étienne Montgolfier developed a hot-air balloon in Annonay, Ardeche, France, and demonstrated it publicly on September 19, 1783, making an unmanned flight lasting 10 minutes. After experimenting with unmanned balloons and flights with animals, the first balloon flight with humans aboard, a tethered flight, performed on or around October 15, 1783, by Jean-Francois Pilatre de Rozier, who made at least one tethered flight from the yard of the Reveillon workshop in the Faubourg Saint-Antoine. Later that same day, Pilatre de Rozier became the second human to ascend into the air, reaching an altitude of , the length of the tether. The first free flight with human passengers was made a few weeks later, on November 21, 1783. King Louis XVI had originally decreed that condemned criminals would be the first pilots, but de Rozier, along with Marquis François d'Arlandes, petitioned successfully for the honor.


title: Hot air balloon

text: The first military use of a hot air balloon happened in 1794 during the battle of Fleurus, when the French used the balloon for observation.


title: Hot air balloon

text: Jean-Pierre Blanchard became the first person to fly a hot air balloon in various countries, including the United States, the Netherlands, and Germany. His most notable flight crossed the English Channel heading to the Dover Castle accompanied by Dr. John Jeffries, which occurred on 7 January 1785. In 1808, Blanchard suffered a heart attack while ballooning above The Hague, fell from his balloon, and experienced fatal injuries. His wife Sophie Blanchard continued his profession, but also died a decade later on a balloon, due to a firework festival causing the hydrogen in the balloon to be set on fire.


title: Hot air balloon

text: Modern hot air balloons, with an onboard heat source, were developed by Ed Yost, beginning during the 1950s; his work resulted in his first successful flight on October 22, 1960. The first modern hot air balloon to be made in the United Kingdom (UK) was the Bristol Belle, built in 1967. Presently, hot air balloons are used primarily for recreation.


title: Hot air balloon

text: Hot air balloons are able to fly to extremely high altitudes. On November 26, 2005 Vijaypat Singhania set the world altitude record for highest hot air balloon flight, reaching . He took off from downtown Mumbai, India, and landed south in Panchale. The previous record of had been set by Per Lindstrand on June 6, 1988, in Plano, Texas.


title: Hot air balloon

text: On January 15, 1991, the "Virgin Pacific Flyer" balloon completed the longest flight in a hot air balloon, when Per Lindstrand (born in Sweden, but resident in the UK) and Richard Branson of the UK flew from Japan to Northern Canada. With a volume of 74,000 cubic meters (2.6 million cubic feet), the balloon envelope was the largest ever built for a hot air craft. Designed to fly in the trans-oceanic jet streams, the "Pacific Flyer" recorded the fastest ground speed for a manned balloon at . The longest duration record was set by Swiss psychiatrist Bertrand Piccard (Auguste Piccard's grandson) and Briton Brian Jones, flying in the Breitling Orbiter 3. It was the first nonstop trip around the world by balloon. The balloon left Château-d'Oex, Switzerland, on March 1, 1999, and landed at 1:02 a.m. on March 21 in the Egyptian desert south of Cairo. The two men exceeded distance, endurance, and time records, traveling 19 days, 21 hours, and 55 minutes. Steve Fossett, flying solo, exceeded the record for briefest time traveling around the world on 3 July 2002 on his sixth attempt, in 320 h 33 min. Fedor Konyukhov flew solo round the world on his first attempt in a hybrid hot air/helium balloon from 11 to 23 July 2016 for a round-the world time of 268 h 20 min.


title: Hot air balloon

text: A hot air balloon for manned flight uses a single-layered, fabric gas bag (lifting "envelope"), with an opening at the bottom called the mouth or throat. Attached to the envelope is a basket, or gondola, for carrying the passengers. Mounted above the basket and centered in the mouth is the "burner", which injects a flame into the envelope, heating the air within. The heater or burner is fueled by propane, a liquefied gas stored in pressure vessels, similar to high-pressure forklift cylinders.


title: Hot air balloon

text: During the manufacturing process, the material is cut into panels and sewn together, along with structural load tapes that carry the weight of the gondola or basket. The individual sections, which extend from the throat to the crown (top) of the envelope, are known as gores or gore sections. Envelopes can have as few as 4 gores or as many as 24 or more.


title: Hot air balloon

text: Envelopes often have a crown ring at their very top. This is a hoop of smooth metal, usually aluminium, and approximately in diameter. Vertical load tapes from the envelope are attached to the crown ring.


title: Hot air balloon

text: At the bottom of the envelope the vertical load tapes are sewn into loops that are connected to cables (one cable per load tape). These cables, often referred to as flying wires, are connected to the basket by carabiners.


title: Hot air balloon

text: The most common technique for sewing panels together is called the "French felled", "French fell", or "double lap" seam. The two pieces of fabric are folded over on each other at their common edge, possibly with a load tape as well, and sewn together with two rows of parallel stitching. Other methods include a "flat lap" seam, in which the two pieces of fabric are held together simply with two rows of parallel stitching, and a "zigzag", where parallel zigzag stitching holds a double lap of fabric.


title: Hot air balloon

text: The fabric (or at least part of it, the top 1/3, for example) may be coated with a sealer, such as silicone or polyurethane, to make it impermeable to air. It is often the degradation of this coating and the corresponding loss of impermeability that ends the effective life of an envelope, not weakening of the fabric itself. Heat, moisture, and mechanical wear-and-tear during set-up and pack-up are the primary causes of degradation. Once an envelope becomes too porous to fly, it may be retired and discarded or perhaps used as a "rag bag": cold-inflated and opened for children to run through. Products for recoating the fabric are becoming available commercially.


title: Hot air balloon

text: A range of envelope sizes is available. The smallest, one-person, basket-less balloons (called "Hoppers" or "Cloudhoppers") have as little as of envelope volume; for a perfect sphere the radius would be around . At the other end of the scale, balloons used by commercial sightseeing operations may be able to carry well over two dozen people, with envelope volumes of up to . The most-used size is about , allowing to carry 3 to 5 people.


title: Hot air balloon

text: The top of the balloon usually has a vent of some sort, enabling the pilot to release hot air to slow an ascent, start a descent, or increase the rate of descent, usually for landing. Some hot air balloons have "turning vents", which are side vents that, when opened, cause the balloon to rotate. Such vents are particularly useful for balloons with rectangular baskets, to facilitate aligning the wider side of the basket for landing.


title: Hot air balloon

text: The most common type of top vent is a disk-shaped flap of fabric called a "parachute vent", invented by Tracy Barnes. The fabric is connected around its edge to a set of "vent lines" that converge in the center. (The arrangement of fabric and lines roughly resembles a parachute—thus the name.) These "vent lines" are themselves connected to a control line that runs to the basket. A parachute vent is opened by pulling on the control line. Once the control line is released, the pressure of the remaining hot air pushes the vent fabric back into place. A parachute vent can be opened briefly while in flight to initiate a rapid descent. (Slower descents are initiated by allowing the air in the balloon to cool naturally.) The vent is pulled open completely to collapse the balloon after landing.


title: Hot air balloon

text: An older, and presently less commonly used, style of top vent is called a "Velcro-style" vent. This too is a disk of fabric at the top of the balloon. However, rather than having a set of "vent lines" that can repeatedly open and close the vent, the vent is secured by "hook and loop" fasteners (such as Velcro) and is only opened at the end of the flight. Balloons equipped with a Velcro-style vent typically have a second "maneuvering vent" built into the side (as opposed to the top) of the balloon. Another common type of top design is the "smart vent", which, rather than lowering a fabric disc into the envelope as in the "parachute" type, gathers the fabric together in the center of the opening. This system can theoretically be used for in-flight maneuvering, but is more commonly used only as a rapid-deflation device for use after landing, of particular value in high winds. Other designs, such as the "pop top" and "MultiVent" systems, have also attempted to address the need for rapid deflation on landing, but the parachute top remains popular as an all-around maneuvering and deflation system.


title: Hot air balloon

text: Besides special shapes, possibly for marketing purposes, there are several variations on the traditional "inverted tear drop" shape. The simplest, often used by home builders, is a hemisphere on top of a truncated cone. More sophisticated designs attempt to minimize the circumferential stress on the fabric, with different degrees of success depending on whether they take fabric weight and varying air density into account. This shape may be referred to as "natural". Finally, some specialized balloons are designed to minimize aerodynamic drag (in the vertical direction) to improve flight performance in competitions.


title: Hot air balloon

text: Hot air balloon baskets are commonly made of woven wicker or rattan. These materials have proven to be sufficiently light, strong, and durable for balloon flight. Such baskets are usually rectangular or triangular in shape. They vary in size from just big enough for two people to large enough to carry thirty. Larger baskets often have internal partitions for structural bracing and to compartmentalize the passengers. Small holes may be woven into the side of the basket to act as foot holds for passengers climbing in or out.


title: Hot air balloon

text: Baskets may also be made of aluminium, especially a collapsible aluminium frame with a fabric skin, to reduce weight or increase portability. These may be used by pilots without a ground crew or who are attempting to set altitude, duration, or distance records. Other specialty baskets include the fully enclosed gondolas used for around-the-world attempts and baskets that consist of little more than a seat for the pilot and perhaps one passenger.


title: Hot air balloon

text: The burner unit gasifies liquid propane, mixes it with air, ignites the mixture, and directs the flame and exhaust into the mouth of the envelope. Burners vary in power output; each will generally produce 2 to 3 MW of heat (7 to 10 million BTUs per hour), with double, triple, or quadruple burner configurations installed where more power is needed. The pilot actuates a burner by opening a propane valve, known as a blast valve. The valve may be spring-loaded, so that it closes automatically, or it may stay open until closed by the pilot. The burner has a pilot light to ignite the propane and air mixture. The pilot light may be lit by the pilot with an external device, such as a flint striker or a lighter, or with a built-in piezoelectric spark.


title: Hot air balloon

text: Where more than one burner is present, the pilot can use one or more at a time, depending on the desired heat output. Each burner has a metal coil of propane tubing the flame shoots through to preheat the incoming liquid propane. The burner unit may be suspended from the mouth of the envelope or supported rigidly over the basket. The burner unit may be mounted on a gimbal to enable the pilot to aim the flame and avoid overheating the envelope fabric. A burner may have a secondary propane valve that releases propane more slowly and thereby generates a different sound. This is called a "whisper burner" and is used for flight over livestock to lessen the chance of spooking them. It also generates a more yellow flame and is used for night glows because it lights up the inside of the envelope better than the primary valve.


title: Hot air balloon

text: Propane fuel tanks are usually cylindrical pressure vessels made from aluminium, stainless steel, or titanium with a valve at one end to feed the burner and to refuel. They may have a fuel gauge and a pressure gauge. Common tank sizes are . They may be intended for upright or horizontal use and may be mounted inside or outside the basket.


title: Hot air balloon

text: The pressure necessary to force the fuel through the line to the burner may be supplied by the vapor pressure of the propane itself, if warm enough, or by the introduction of an inert gas such as nitrogen. Tanks may be preheated with electrical heat tapes to produce sufficient vapor pressure for cold-weather flying. Warmed tanks are usually also wrapped in an insulating blanket to preserve heat during the setup and flight.


title: Hot air balloon

text: A balloon may be outfitted with a variety of instruments to aid the pilot. These commonly include an altimeter, a rate-of-climb (vertical-speed) indicator known as a variometer, envelope (air) temperature, and ambient (air) temperature. A GPS receiver can be useful to indicate ground speed (traditional aircraft air-speed indicators would be useless) and direction.


title: Hot air balloon

text: Increasing the air temperature inside the envelope makes it less dense than the surrounding (ambient) air. The balloon floats because of the buoyant force exerted on it. This force is the same force that acts on objects when they are in water and is described by Archimedes' principle. The amount of lift (or buoyancy) provided by a hot air balloon depends primarily upon the difference between the temperature of the air inside the envelope and the temperature of the air outside the envelope. For most envelopes made of nylon fabric, the maximal internal temperature is limited to approximately 120 °C (250 °F).


title: Hot air balloon

text: The melting point of nylon is significantly greater than this maximal operating temperature — about 230 °C (450 °F) — but higher temperatures cause the strength of the nylon fabric to degrade more quickly over time. With a maximal operating temperature of 120 °C (250 °F), balloon envelopes can generally be flown for between 400 and 500 hours before the fabric needs to be replaced. Many balloon pilots operate their envelopes at temperatures significantly less than the maximum to extend envelope-fabric life.


title: Hot air balloon

text: The density of air at is about . The total lift for a balloon of heated to would be . This is just enough to generate neutral buoyancy for the total system mass (not including the heated air trapped in the envelope, of course) stated in the previous section. Liftoff would require a slightly greater temperature, depending on the desired rate of climb. In reality, the air contained in the envelope is not all at the same temperature, as the accompanying thermal image shows, and so these calculations are based on averages.


title: Hot air balloon

text: For typical atmospheric conditions (), a hot air balloon heated to requires about 3.91 m of envelope volume to lift 1 kilogram (equivalently, 62.5 cu ft/lb). The precise amount of lift provided depends not only upon the internal temperature mentioned above, but the external temperature, altitude above sea level, and humidity of the air surrounding. On a warm day, a balloon cannot lift as much as on a cool day, because the temperature required for launch will exceed the maximum sustainable for nylon envelope fabric. Also, in the lower atmosphere, the lift provided by a hot air balloon decreases about 3% per 1,000 m (1% per 1,000 ft) of altitude gained.


title: Hot air balloon

text: Standard hot air balloons are known as Montgolfier balloons and rely solely on the buoyancy of hot air provided by the burner and contained by the envelope. This style of balloon was developed by the Montgolfier brothers and had its first public demonstration on 4 June 1783 with an unmanned flight lasting 10 minutes, followed later that year with manned flights.


title: Hot air balloon

text: The 1785 Rozière balloon, a type of hybrid balloon, named after its creator, Jean-François Pilâtre de Rozier, has a separate cell for a lighter-than-air gas (typically helium), as well as a cone below for hot air (as is used in a hot air balloon) to heat the helium at night. Hydrogen gas was used in the very early stages of development, but was quickly abandoned due to the danger of introducing an open flame near the gas. All modern Roziere balloons now use helium as a lifting gas.


title: Hot air balloon

text: Solar balloons are hot air balloons that use just solar energy captured by a dark envelope to heat the air inside.


title: Hot air balloon

text: Hot air balloon can be steered to a limited degree by changing the altitude of the flight. Wind in the northern hemisphere tends to turn east due to coriolis effect as the altitude increases.


title: Hot air balloon

text: To help ensure the safety of pilot and passengers, a hot air balloon may carry several pieces of safety equipment.


title: Hot air balloon

text: To relight the burner if the pilot light goes out and the optional piezo ignition fails, the pilot should have ready access to a means of backup ignition, such as a flint spark lighter. Many systems, especially those that carry passengers, have completely duplicate fuel and burner systems: two fuel tanks, connected to two separate hoses, which feed two distinct burners. This enables a safe landing in the case of a blockage somewhere in one system or if a system must be disabled because of a fuel leak.


title: Hot air balloon

text: A fire extinguisher suitable for extinguishing propane fires is useful. Most balloons carry a 1 or 2 kg AB:E type fire extinguisher.


title: Hot air balloon

text: A handling or drop line is mandatory safety equipment in many countries. This is a rope or webbing of 20–30 meters in length attached to the balloon basket with a quick-release connection at one end. In very calm winds the balloon pilot can throw the handling line from the balloon so that the ground crew can guide the balloon safely away from obstructions on the ground.


title: Hot air balloon

text: For commercial passenger balloons, a pilot restraint harness is mandatory in some countries. This consists of a hip belt and a webbing line that together allow for some movement while preventing the pilot from being ejected from the basket during a hard landing.


title: Hot air balloon

text: At a minimum, the pilot should wear leather or flame-retardant fiber (such as nomex) gloves, so that they may shut off a gas valve in the case of a leak, even if there is a flame present; quick action in this regard can turn a potential catastrophe into a mere inconvenience. The pilot should additionally wear flame-resistant clothing covering their arms and legs; either natural fiber, such as cotton, linen, hemp, or wool, or engineered flame-retardant fiber, such as nomex, is acceptable in this capacity. Most engineered fibers (with the exception of rayon, which is also safe to wear) are thermoplastic; many are also hydrocarbons. This makes such fabrics very much unsuitable to wear near high temperatures, since non-flame-retardant thermoplastics will melt onto the wearer, and most hydrocarbons, whether fibrous or not, are suitable to use as fuels. Natural fiber will singe rather than melt or burn readily, and flame-retardant fiber generally has a very high melting point and is intrinsically non-flammable. Many pilots also advise their passengers to wear similar protective clothing that covers their arms and legs, as well as strong shoes or boots that offer good ankle support. Finally, some balloon systems, especially those that hang the burner from the envelope instead of supporting it rigidly from the basket, require the use of helmets by the pilot and passengers.


title: Hot air balloon

text: The ground crew should wear gloves whenever there is a possibility of handling ropes or lines. The mass and exposed surface to air movement of a medium-sized balloon is sufficient to cause rope friction burns to the hands of anyone trying to stop or prevent movement. The ground crew should also wear sturdy shoes and at least long pants in case of the need to access a landing or landed balloon in rough or overgrown terrain.


title: Hot air balloon

text: As with aircraft, hot air balloons require regular maintenance to remain airworthy. As aircraft made of fabric and that lack direct horizontal control, hot air balloons may occasionally require repairs to rips or snags. While some operations, such as cleaning and drying, may be performed by the owner or pilot, other operations, such as sewing, must be performed by a qualified repair technician and recorded in the balloon's maintenance log book.


title: Hot air balloon

text: To ensure long life and safe operation, the envelope should be kept clean and dry. This prevents mold and mildew from forming on the fabric and abrasion from occurring during packing, transport, and unpacking due to contact with foreign particles. In the event of a landing in a wet (because of precipitation or early morning or late evening dew) or muddy location (farmer's field), the envelope should be cleaned and laid out or hung to dry.


title: Hot air balloon

text: The burner and fuel system must also be kept clean to ensure safe operation on demand. Damaged fuel hoses need to be replaced. Stuck or leaky valves must be repaired or replaced. The wicker basket may require occasional refinishing or repair. The skids on its bottom may require occasional replacement.


title: Hot air balloon

text: Balloons in most parts of the world are maintained in accordance with a fixed manufacturer's maintenance schedule that includes regular (100 flight hours or 12 month) inspections, in addition to maintenance work to correct any damage. In Australia, balloons used for carrying commercial passengers must be inspected and maintained by approved workshops.


title: Hot air balloon

text: In the case of a snag, burn, or rip in the envelope fabric, a patch may be applied or the affected panel completely replaced. Patches may be held in place with glue, tape, stitching, or a combination of these techniques. Replacing an entire panel requires the stitching around the old panel to be removed, and a new panel to be sewn in with the appropriate technique, thread, and stitch pattern.


title: Hot air balloon

text: Depending on the size of the balloon, location, and intended use, hot air balloons and their pilots need to comply with a variety of regulations.


title: Hot air balloon

text: As with other aircraft in the US, balloons must be registered (have an N-number), have an airworthiness certificate, and pass annual inspections. Balloons below a certain size (empty weight of less than 155 pounds or 70 kg including envelope, basket, burners and empty fuel tanks) can be used as an ultralight aircraft.


title: Hot air balloon

text: and typically become members of regional hot air ballooning clubs. Commercial operations carrying fare paying passengers or charging for promotional flights must operate under an Air Operators Certificate from the Australian Civil Aviation and Safety Authority (CASA) with a nominated Chief Pilot. Pilots must have different degrees of experience before they are allowed to progress to larger balloons. Hot air balloons must be registered aircraft with CASA and are subject to regular airworthiness checks by authorised personnel.


title: Hot air balloon

text: In the UK, the person in command must hold a valid Private Pilot's Licence issued by the Civil Aviation Authority specifically for ballooning; this is known as the PPL(B). There are two types of commercial balloon licences: CPL(B) Restricted and CPL(B) (Full). The CPL(B) Restricted is required if the pilot is undertaking work for a sponsor or being paid by an external agent to operate a balloon. The pilot can fly a sponsored balloon with everything paid for with a PPL unless asked to attend any event. Then a CPL(B) Restricted is required. The CPL(B) is required if the pilot is flying passengers for money. The balloon then needs a transport category C of A (certificate of air worthiness). If the pilot is only flying sponsor's guests and not charging money for flying other passengers, then the pilot is exempted from holding an AOC (air operator's certificate) though a copy of it is required. For passenger flying the balloon also requires a maintenance log.


title: Hot air balloon

text: In the United States, a pilot of a hot air balloon must have a pilot certificate from the Federal Aviation Administration (FAA), carrying the rating of "Lighter-than-air free balloon", and unless the pilot is also qualified to fly gas balloons, will also carry this limitation: "Limited to hot-air balloons with airborne heater". A pilot does not need a license to fly an ultralight aircraft, but training is highly advised, and some hot-air balloons meet the criteria.


title: Hot air balloon

text: To carry paying passengers for hire (and attend some balloon festivals), a pilot must have a commercial pilot certificate. Commercial hot air balloon pilots may also act as hot air balloon flight instructors. While most balloon pilots fly for the pure joy of floating through the air, many are able to make a living as a professional balloon pilot. Some professional pilots fly commercial passenger sightseeing flights, while others fly corporate advertising balloons.


title: Hot air balloon

text: The largest manufacturer of hot air balloons is Cameron Balloons of Bristol, England, which also owns Lindstrand Balloons of Oswestry, England. Cameron Balloons, Lindstrand Balloons and another English balloon manufacturing company Thunder and Colt (since acquired by Cameron) have been innovators and developers of special shaped balloons. These hot-air balloons use the same principle of lift as conventional inverted teardrop-shaped balloons, but often sections of the special balloon envelope shape do not contribute to the balloon's ability to stay aloft.


title: Hot air balloon

text: The second largest manufacturer of hot air balloons is Ultramagic company, based in Spain, which produces from 80 to 120 balloons per year. Ultramagic can produce very large balloons, such as the N-500 that accommodates as many as 27 persons in the basket, and has also produced many balloons with special shapes, as well as cold-air inflatables.


title: Hot air balloon

text: One of the three largest companies in the world is Kubicek Balloons. From its factory in Brno, Czechia the company ships its products worldwide. Produces from 100 to 115 balloons per year. Kubicek company also focus on special shape balloons, FAA/EASA type certified and are delivered with a Standard Airworthiness Certificate.


title: Hot air balloon

text: In the USA Aerostar International, Inc. of Sioux Falls, South Dakota was North America's largest balloon manufacturer and a close second in world manufacturing before ceasing to build balloons in January 2007. The oldest U.S. certified manufacturer is now Adams Balloons out of Albuquerque, New Mexico. Firefly Balloons, formerly The Balloon Works, is a manufacturer of hot air balloons in Statesville, North Carolina. Another manufacturer is Head Balloons, Inc. of Helen, Georgia.


title: Hot air balloon

text: The major manufacturers in Canada are Sundance Balloons and Fantasy Sky Promotions. Other manufacturers include Kavanagh Balloons of Australia, Schroeder Fire Balloons of Germany, Kubicek Balloons of the Czech Republic, and LLopis Balloons of France.


title: Heian period

text: The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japanese. It is a period in Japanese history when the Chinese influences were in decline and the national culture matured. The Heian period is also considered the peak of the Japanese imperial court and noted for its art, especially poetry and literature. Two types of Japanese script emerged, including katakana, a phonetic script which was abbreviated into hiragana, a cursive alphabet with a unique writing method distinctive to Japan. This gave rise to Japan's famous vernacular literature, with many of its texts written by court women who were not as educated in Chinese compared to their male counterparts.


title: Heian period

text: Although the Imperial House of Japan had power on the surface, the real power was in the hands of the Fujiwara clan, a powerful aristocratic family who had intermarried with the imperial family. Many emperors actually had mothers from the Fujiwara family. The economy mostly existed through barter and trade, while the shōen system enabled the accumulation of wealth by an aristocratic elite. Even though the Heian period was one of national peace, the government failed to effectively police the territory, leading to robberies unto travellers.


title: Heian period

text: The Heian period was preceded by the Nara period and began in 794 AD after the movement of the capital of Japan to Heian-kyō (modern Kyoto), by the 50th emperor, Emperor Kanmu. Kanmu first tried to move the capital to Nagaoka-kyō, but a series of disasters befell the city, prompting the emperor to relocate the capital a second time, to Heian. A rebellion occurred in China in the last years of the 9th century, making the political situation unstable. The Japanese missions to Tang China were suspended and the influx of Chinese exports halted, a fact which facilitated the independent growth of Japanese culture called . Therefore, the Heian Period is considered a high point in Japanese culture that later generations have always admired. The period is also noted for the rise of the samurai class, which would eventually take power and start the feudal period of Japan.


title: Heian period

text: Nominally, sovereignty lay in the emperor but in fact, power was wielded by the Fujiwara nobility. However, to protect their interests in the provinces, the Fujiwara, and other noble families required guards, police and soldiers. The warrior class made steady political gains throughout the Heian period. As early as 939 AD, Taira no Masakado threatened the authority of the central government, leading an uprising in the eastern province of Hitachi, and almost simultaneously, Fujiwara no Sumitomo rebelled in the west. Still, a true military takeover of the Japanese government was centuries away, when much of the strength of the government would lie within the private armies of the shogunate.


title: Heian period

text: The entry of the warrior class into court influence was a result of the Hōgen Rebellion. At this time Taira no Kiyomori revived the Fujiwara practices by placing his grandson on the throne to rule Japan by regency. Their clan, the Taira, would not be overthrown until after the Genpei War, which marked the start of the Kamakura shogunate. The Kamakura period began in 1185 when Minamoto no Yoritomo seized power from the emperors and established the shogunate in Kamakura.


title: Heian period

text: When Emperor Kanmu moved the capital to Heian-kyō (Kyoto), which remained the imperial capital for the next 1,000 years, he did so not only to strengthen imperial authority but also to improve his seat of government geopolitically. Nara was abandoned after only 70 years in part due to the ascendancy of Dōkyō and the encroaching secular power of the Buddhist institutions there. Kyoto had good river access to the sea and could be reached by land routes from the eastern provinces. The early Heian period (784–967) continued Nara culture; the Heian capital was patterned on the Chinese Tang capital at Chang'an, as was Nara, but on a larger scale than Nara. Kanmu endeavored to improve the Tang-style administrative system which was in use. Known as the "Ritsuryō Code", this system attempted to recreate the Tang legal system in Japan, despite the "tremendous differences in the levels of development between the two countries". Despite the decline of the Taika–Taihō reforms, imperial government was vigorous during the early Heian period. Kanmu's avoidance of drastic reform decreased the intensity of political struggles, and he became recognized as one of Japan's most forceful emperors.


title: Heian period

text: Although Kanmu had abandoned universal conscription in 792, he still waged major military offensives to subjugate the Emishi, possible descendants of the displaced Jōmon, living in northern and eastern Japan. After making temporary gains in 794, in 797, Kanmu appointed a new commander, Sakanoue no Tamuramaro, under the title "Seii Taishōgun" ("Barbarian-subduing generalissimo"). By 801, the "shōgun" had defeated the Emishi and had extended the imperial domains to the eastern end of Honshū. Imperial control over the provinces was tenuous at best, however. In the ninth and tenth centuries, much authority was lost to the great families, who disregarded the Chinese-style land and tax systems imposed by the government in Kyoto. Stability came to Japan, but, even though succession was ensured for the imperial family through heredity, power again concentrated in the hands of one noble family, the Fujiwara which also helped Japan develop more.


title: Heian period

text: Following Kanmu's death in 806 and a succession struggle among his sons, two new offices were established in an effort to adjust the Taika–Taihō administrative structure. Through the new Emperor's Private Office, the emperor could issue administrative edicts more directly and with more self-assurance than before. The new Metropolitan Police Board replaced the largely ceremonial imperial guard units. While these two offices strengthened the emperor's position temporarily, soon they and other Chinese-style structures were bypassed in the developing state. In 838 the end of the imperial-sanctioned missions to Tang China, which had begun in 630, marked the effective end of Chinese influence. Tang China was in a state of decline, and Chinese Buddhists were severely persecuted, undermining Japanese respect for Chinese institutions. Japan began to turn inward.


title: Heian period

text: As the Soga clan had taken control of the throne in the sixth century, the Fujiwara by the ninth century had intermarried with the imperial family, and one of their members was the first head of the Emperor's Private Office. Another Fujiwara became regent, Sesshō for his grandson, then a minor emperor and yet another was appointed Kampaku. Toward the end of the 9th century, several emperors tried but failed, to check the Fujiwara. For a time, however, during the reign of Emperor Daigo (897–930), the Fujiwara regency was suspended as he ruled directly.


title: Heian period

text: Nevertheless, the Fujiwara were not demoted by Daigo but actually became stronger during his reign. Central control of Japan had continued to decline, and the Fujiwara, along with other great families and religious foundations, acquired ever larger "shōen" and greater wealth during the early tenth century. By the early Heian period, the "shōen" had obtained legal status, and the large religious establishments sought clear titles in perpetuity, waiver of taxes, and immunity from government inspection of the "shōen" they held. Those people who worked the land found it advantageous to transfer title to "shōen" holders in return for a share of the harvest. People and lands were increasingly beyond central control and taxation, a "de facto" return to conditions before the Taika Reform.


title: Heian period

text: Within decades of Daigo's death, the Fujiwara had absolute control over the court. By the year 1000, Fujiwara no Michinaga was able to enthrone and dethrone emperors at will. Little authority was left for traditional institutions, and government affairs were handled through the Fujiwara clan's private administration. The Fujiwara had become what historian George B. Sansom has called "hereditary dictators".


title: Heian period

text: Despite their usurpation of imperial authority, the Fujiwara presided over a period of cultural and artistic flowering at the imperial court and among the aristocracy. There was great interest in graceful poetry and vernacular literature. Two types of phonetic Japanese script: katakana, a simplified script that was developed by using parts of Chinese characters, was abbreviated to hiragana, a cursive syllabary with a distinct writing method that was uniquely Japanese. Hiragana gave written expression to the spoken word and, with it, to the rise in Japan's famous vernacular literature, much of it written by court women who had not been trained in Chinese as had their male counterparts. Three late-tenth-century and early-11th-century women presented their views of life and romance at the Heian court in "Kagerō Nikki" by "the mother of Fujiwara Michitsuna", "The Pillow Book" by Sei Shōnagon and "The Tale of Genji" by Murasaki Shikibu. Indigenous art also flourished under the Fujiwara after centuries of imitating Chinese forms. Vividly colored yamato-e, Japanese style paintings of court life and stories about temples and shrines became common in the mid-to-late Heian period, setting patterns for Japanese art to this day.


title: Heian period

text: As culture flourished, so did decentralization. Whereas the first phase of "shōen" development in the early Heian period had seen the opening of new lands and the granting of the use of lands to aristocrats and religious institutions, the second phase saw the growth of patrimonial "house governments", as in the old clan system. In fact, the form of the old clan system had remained largely intact within the great old centralized government. New institutions were now needed in the face of social, economic, and political changes. The Taihō Code lapsed, its institutions relegated to ceremonial functions. Family administrations now became public institutions. As the most powerful family, the Fujiwara governed Japan and determined the general affairs of state, such as succession to the throne. Family and state affairs were thoroughly intermixed, a pattern followed among other families, monasteries, and even the imperial family. Land management became the primary occupation of the aristocracy, not so much because direct control by the imperial family or central government had declined but more from strong family solidarity and a lack of a sense of Japan as a single nation.


title: Heian period

text: Under the early courts, when military conscription had been centrally controlled, military affairs had been taken out of the hands of the provincial aristocracy. But as the system broke down after 792, local power holders again became the primary source of military strength. The re-establishment of an efficient military system was made gradually through a process of trial-and-error. At that time the imperial court did not possess an army but rather relied on an organization of professional warriors composed mainly of oryoshi, which were appointed to an individual province and tsuibushi, which were appointed over imperial circuits or for specific tasks. This gave rise to the Japanese military class. Nonetheless, final authority rested with the imperial court.


title: Heian period

text: "Shōen" holders had access to manpower and, as they obtained improved military technology (such as new training methods, more powerful bows, armor, horses, and superior swords) and faced worsening local conditions in the ninth century, military service became part of "shōen" life. Not only the "shōen" but also civil and religious institutions formed private guard units to protect themselves. Gradually, the provincial upper class was transformed into a new military elite of samurai.


title: Heian period

text: Bushi interests were diverse, cutting across old power structures to form new associations in the tenth century. Mutual interests, family connections, and kinship were consolidated in military groups that became part of family administration. In time, large regional military families formed around members of the court aristocracy who had become prominent provincial figures. These military families gained prestige from connections to the imperial court and court-granted military titles and access to manpower. The Fujiwara family, Taira clan, and Minamoto clan were among the most prominent families supported by the new military class.


title: Heian period

text: A decline in food production, the growth of the population, and competition for resources among the great families all led to the gradual decline of Fujiwara power and gave rise to military disturbances in the mid-tenth and eleventh centuries. Members of the Fujiwara, Taira, and Minamoto families—all of whom had descended from the imperial family—attacked one another, claimed control over vast tracts of conquered land, set up rival regimes, and generally upset the peace.


title: Heian period

text: The Fujiwara controlled the throne until the reign of Emperor Go-Sanjō (1068–1073), the first emperor not born of a Fujiwara mother since the ninth century. Go-Sanjo, determined to restore imperial control through strong personal rule, implemented reforms to curb Fujiwara influence. He also established an office to compile and validate estate records with the aim of reasserting central control. Many "shōen" were not properly certified, and large landholders, like the Fujiwara, felt threatened with the loss of their lands. Go-Sanjo also established the ( "Office of the Cloistered Emperor"), which was held by a succession of emperors who abdicated to devote themselves to behind-the-scenes governance, or "insei".


title: Heian period

text: The "In-no-chō" filled the void left by the decline of Fujiwara power. Rather than being banished, the Fujiwara were mostly retained in their old positions of civil dictator and minister of the center while being bypassed in decision making. In time, many of the Fujiwara were replaced, mostly by members of the rising Minamoto clan. While the Fujiwara fell into disputes among themselves and formed northern and southern factions, the "insei" system allowed the paternal line of the imperial family to gain influence over the throne. The period from 1086 to 1156 was the age of supremacy of the "In-no-chō" and of the rise of the military class throughout the country. Military might rather than civil authority dominated the government.


title: Heian period

text: A struggle for succession in the mid-twelfth century gave the Fujiwara an opportunity to regain their former power. Fujiwara no Yorinaga sided with the retired emperor in a violent battle in 1156 against the heir apparent, who was supported by the Taira and Minamoto (Hōgen Rebellion). In the end, the Fujiwara were destroyed, the old system of government supplanted, and the "insei" system left powerless as bushi took control of court affairs, marking a turning point in Japanese history. In 1159, the Taira and Minamoto clashed (Heiji Rebellion), and a twenty-year period of Taira ascendancy began.


title: Heian period

text: Taira no Kiyomori emerged as the real power in Japan following the Fujiwara's destruction, and he would remain in command for the next 20 years. He gave his daughter Tokuko in marriage to the young emperor Takakura, who died at only 19, leaving their infant son Antoku to succeed to the throne. Kiyomori filled no less than 50 government posts with his relatives, rebuilt the Inland Sea, and encouraged trade with Song China. He also took aggressive actions to safeguard his power when necessary, including the removal and exile of 45 court officials and the razing of two troublesome temples, Todai-ji and Kofuku-ji.


title: Heian period

text: The Taira were seduced by court life and ignored problems in the provinces , where the Minamoto clan were rebuilding their strength. In 1183, two years after Kiyomori's death, Yoritomo Minamoto dispatched his brothers Yoshitsune and Noriyori to attack Kyoto. The Taira were routed and forced to flee, and the Empress Dowager tried to drown herself and the 7-year old Emperor (he perished, but his mother survived). Takakura's other son succeeded as Emperor Go-Toba.


title: Heian period

text: With Yoritomo firmly established, the "bakufu" system that governed Japan for the next seven centuries was in place. He appointed military governors, or "shugo", to rule over the provinces, and stewards, or "jito" to supervise public and private estates. Yoritomo then turned his attention to the elimination of the powerful Fujiwara family, which sheltered his rebellious brother Yoshitsune. Three years later, he was appointed "shōgun" in Kyoto. One year before his death in 1199, Yoritomo expelled the teenaged emperor Go-Toba from the throne. Two of Go-Toba's sons succeeded him, but they would also be removed by Yoritomo's successors to the shogunate.


title: Heian period

text: Tendai is the Japanese version of the Tiantai school from China, which is based on the Lotus Sutra, one of the most important sutras in Mahayana Buddhism. It was brought to Japan by the monk Saichō. An important element of Tendai doctrine was the suggestion that enlightenment was accessible to "every creature". Saichō also sought independent ordination for Tendai monks. A close relationship developed between the Tendai monastery complex on Mount Hiei and the imperial court in its new capital at the foot of the mountain. As a result, Tendai emphasized great reverence for the emperor and the nation. Emperor Kanmu himself was a notable patron of the otherworldly Tendai sect, which rose to great power over the ensuing centuries.


title: Heian period

text: Shingon is the Japanese version of the Zhenyen school from China, which is based on Vajrayana Buddhism. It was brought to Japan by the monk Kūkai. Shingon Buddhism emphasizes the use of symbols, rituals, incantations and mandalas, which gave it a wide appeal. Kūkai greatly impressed the emperors who succeeded Emperor Kanmu, and also generations of Japanese, not only with his holiness but also with his poetry, calligraphy, painting, and sculpture. Both Kūkai and Saichō aimed to connect state and religion and establish support from the aristocracy, leading to the notion of "aristocratic Buddhism".


title: Heian period

text: Although written Chinese ("kanbun") remained the official language of the Heian period imperial court, the introduction and widespread use of kana saw a boom in Japanese literature. Despite the establishment of several new literary genres such as the novel and narrative "monogatari" (物語) and essays, literacy was only common among the court and Buddhist clergy.


title: Heian period

text: Poetry, in particular, was a staple of court life. Nobles and ladies-in-waiting were expected to be well versed in the art of writing poetry as a mark of their status. Every occasion could call for the writing of a verse, from the birth of a child to the coronation of an emperor, or even a pretty scene of nature. A well-written poem could easily make or break one's reputation, and often was a key part of social interaction. Almost as important was the choice of calligraphy, or handwriting, used. The Japanese of this period believed handwriting could reflect the condition of a person's soul: therefore, poor or hasty writing could be considered a sign of poor breeding. Whether the script was Chinese or Japanese, good writing and artistic skill were paramount to social reputation when it came to poetry. Sei Shōnagon mentions in her "Pillow Book" that when a certain courtier tried to ask her advice about how to write a poem to the Empress Sadako, she had to politely rebuke him because his writing was so poor.


title: Heian period

text: The lyrics of the modern Japanese national anthem, "Kimigayo", were written in the Heian period, as was "The Tale of Genji" by Murasaki Shikibu, which was extremely important to the Heian court, and one of the first novels ever written. Murasaki Shikibu's contemporary and rival Sei Shōnagon's revealing observations and musings as an attendant in the Empress' court were recorded collectively as "The Pillow Book" in the 990s, which revealed the quotidian capital lifestyle. The Heian period produced a flowering of poetry including works of Ariwara no Narihira, Ono no Komachi, Izumi Shikibu, Murasaki Shikibu, Saigyō and Fujiwara no Teika. The famous Japanese poem known as the Iroha (いろは), of uncertain authorship, was also written during the Heian period.


title: Heian period

text: During the Heian period, beauty was widely considered an important part of what made one a "good" person. In cosmetic terms, aristocratic men and women powdered their faces and blackened their teeth, the latter termed "ohaguro". The male courtly ideal included a faint mustache and thin goatee, while women's mouths were painted small and red, and their eyebrows were plucked or shaved and redrawn higher on the forehead ("hikimayu").


title: Heian period

text: Women cultivated shiny, black flowing hair and a courtly woman's formal dress included a complex "twelve-layered robe" called "jūnihitoe", though the actual number of layers varied. Costumes were determined by office and season, with a woman's robes, in particular, following a system of color combinations representing flowers, plants, and animals specific to a season or month, (see the Japanese Wikipedia entries and ).


title: Heian period

text: While the Heian period was an unusually long period of peace, it can also be argued that the period weakened Japan economically and led to poverty for all but a tiny few of its inhabitants. The control of rice fields provided a key source of income for families such as the Fujiwara and was a fundamental base of their power. The aristocratic beneficiaries of Heian culture, the "Ryōmin" (良民 "Good People") numbered about 5,000 in a land of perhaps five million. One reason the samurai were able to take power was that the ruling nobility proved incompetent at managing Japan and its provinces. By the year 1000, the government no longer knew how to issue currency and money was gradually disappearing. Instead of a fully realized system of money circulation, rice was the primary unit of exchange. The lack of a solid medium of economic exchange is implicitly illustrated in novels of the time. For instance, messengers were rewarded with useful objects such as an old silk kimono, rather than being paid a monetary fee.


title: Heian period

text: The Fujiwara rulers failed to maintain adequate police forces, which left robbers free to prey on travelers. This is implicitly illustrated in novels by the terror that night travel inspired in the main characters. The shōen system enabled the accumulation of wealth by an aristocratic elite; the economic surplus can be linked to the cultural developments of the Heian period and the "pursuit of arts". The major Buddhist temples in Heian-kyō and Nara also made use of the shōen. The establishment of branches rurally and integration of some Shinto shrines within these temple networks reflects a greater "organizational dynamism".


title: Heian period

text: The iconography of the Heian period is widely known in Japan, and depicted in various media, from traditional festivals to anime. Various festivals feature Heian dress – most notably Hinamatsuri (doll festival), where the dolls wear Heian dress, but also numerous other festivals, such as Aoi Matsuri in Kyoto (May) and Saiō Matsuri in Meiwa, Mie (June), both of which feature the jūnihitoe 12-layer dress. Traditional horseback archery (yabusame) festivals, which date from the beginning of the Kamakura period (immediately following the Heian period) feature similar dress.


title: Andy Whitfield

text: Andrew Whitfield (17 October 1971 – 11 September 2011) was a Welsh actor. He was best known for his leading role in the Starz television series "".


title: Andy Whitfield

text: Whitfield and his family came to live in Bull Bay, Anglesey, Wales in 1976. He attended Ysgol Gynradd Amlwch and then Ysgol Syr Thomas Jones until the age of 18. He studied civil engineering at Sheffield Hallam University in England. He moved to Australia in 1999 to work as an engineer in Lidcombe, before later settling in Sydney. He appeared in several Australian television series, such as "Opening Up", "All Saints", "The Strip", "Packed to the Rafters", and "McLeod's Daughters".


title: Andy Whitfield

text: Whitfield gained his first prominent role in the Australian supernatural film "Gabriel". He also starred in the 2010 television series "", which was filmed in New Zealand. Whitfield also appeared in the Australian thriller "The Clinic" starring opposite Tabrett Bethell (of "Legend of the Seeker" fame) which was shot in Deniliquin.


title: Andy Whitfield

text: In August 2010, Whitfield teamed up with Freddie Wong and created a 2-minute YouTube video named "Time Crisis", based on the video game series of the same name. Whitfield made a brief, uncredited voice-only appearance in the prequel mini-series "", which premiered on 21 January 2011.


title: Andy Whitfield

text: A documentary titled "Be Here Now" premiered at the 2015 Los Angeles Film Festival. It follows the journey and struggle of Whitfield and his family as he undergoes chemotherapy treatment for non-Hodgkin Lymphoma. It was later released on Netflix as "Be Here Now: The Andy Whitfield Story."


title: Andy Whitfield

text: In March 2010, Whitfield was diagnosed with stage IV non-Hodgkin lymphoma and began undergoing treatment immediately in New Zealand. This delayed production of season two of "Spartacus: Vengeance". While waiting for Whitfield's treatment and expected recovery, Starz produced a six-part prequel, "Spartacus: Gods of the Arena", with only a brief uncredited voiceover from the actor. Although declared cancer-free in June 2010, a routine medical check in September 2010 revealed a relapse and Whitfield was compelled to abandon the role. Starz recast Australian actor Liam McIntyre as Whitfield's successor.


title: Andy Whitfield

text: Whitfield died of non-Hodgkin lymphoma in Sydney, New South Wales, Australia, on 11 September 2011, 18 months after his initial cancer diagnosis.


title: The Boy in the Striped Pyjamas

text: The Boy in the Striped Pyjamas is a 2006 Holocaust novel by Irish novelist John Boyne. Much like the process he undertakes when writing most of his novels, Boyne has said that he wrote the entire first draft in two and a half days, without sleeping much, but also that he was quite a serious student of Holocaust-related literature for years before the idea for the novel even came to him. The book has received mixed reviews; while positive reviews praise the story as a moral, negative reviews attack the book's historical inconsistencies, and the potential damage it could cause to people's Holocaust education.


title: The Boy in the Striped Pyjamas

text: In both 2007 and 2008, it was the best-selling book of the year in Spain, and it reached number one on the "New York Times" bestseller list. The book was adapted into a film of the same name in 2008, a ballet in 2017 and an opera entitled "A Child In Striped Pyjamas" in 2023.


title: The Boy in the Striped Pyjamas

text: John Boyne has described the conception of his novel as an idea popping into his head of "two boys, the mirror of each other, sitting either side of a wire fence". While the conception of the book came about fast, his inspiration for writing has a more lengthy foundation. Boyne has stated that his style and writing process has been influenced by Malcolm Bradbury at the University of East Anglia, who suggested he write every day without rest days.


title: The Boy in the Striped Pyjamas

text: Unlike other novels he has written, Boyne has described how he wrote the first draft of "The Boy in the Striped Pyjamas" in roughly two and a half days, with the idea for the novel coming to him on Tuesday, 27 April, then wrote non-stop until Friday at noon. Afterwards, he ended up writing ten different drafts before sending his book to the editor. As for the subject material and research that Boyne undertook to write the book, Professor Gerd Bayer from the University of Erlangen has stated that Boyne's reader should not rely on "the actual truth-value of his text".


title: The Boy in the Striped Pyjamas

text: Bruno is a nine-year-old boy growing up during World War II in Berlin. He lives with his parents, his twelve-year-old sister Gretel whom he has nicknamed 'A Hopeless Case', and maids, one of whom is named Maria and another is a Jewish chef named Pavel. After a visit by Adolf Hitler, whose title The Führer Bruno commonly mispronounces as "Fury", Bruno's father Ralf is promoted to Commandant of the death camp Auschwitz, which Bruno mispronounces as "Out-With".


title: The Boy in the Striped Pyjamas

text: Bruno is initially upset about having to move to Auschwitz and is almost in tears at the prospect of leaving his 'best friends for life, Daniel, Karl, and Martin. From the house at Auschwitz, Bruno sees the camp in which the prisoners' uniforms appear to him to be "striped pyjamas". One day Bruno decides to explore the wire fence surrounding the camp. He meets a Jewish boy, Shmuel, who he learns shares his birthday (April 15th) and age. Shmuel says that his father, grandfather, and brother are with him on his side of the fence, but he is separated from his mother. Bruno and Shmuel talk and become very good friends although Bruno still does not understand very much about Shmuel or his life. Nearly every day, unless it is raining, Bruno goes to see Shmuel and sneaks him food. Over time, Bruno notices that Shmuel is rapidly losing weight.


title: The Boy in the Striped Pyjamas

text: Bruno concocts a plan with Shmuel to sneak into the camp to look for Shmuel's father, who has gone missing. Shmuel brings a set of prison clothes and Bruno leaves his own clothes outside the fence. As they search the camp they are captured, added to a group of prisoners on a "march", and led into a gas chamber, which Bruno assumes is simply a rain shelter. In the gas chamber, Bruno apologizes to Shmuel for not finding his father and tells Shmuel that he is his best friend for life. It is not made clear if Shmuel answers before the doors close and the lights go out, although Bruno determines to never let go of Shmuel's hand.


title: The Boy in the Striped Pyjamas

text: Bruno is never seen again, his clothes being discovered by a soldier days later. His mother, Elsa, spends months searching for him, even returning to their old home, before at last moving back to Berlin with Gretel, who isolates herself in her room. Ralf spends a year more at Auschwitz, becoming ruthless and cold to his subordinates. A year later, he returns to the place where Bruno's clothes were found, deduces how his son disappeared and collapses to his knees in grief. Months later, Allied troops liberate the camp and Ralf, wracked with guilt and self-loathing, allows himself to be taken prisoner without resistance.


title: The Boy in the Striped Pyjamas

text: The book ends with the phrase "Of course, all of this happened a long time ago and nothing like that could ever happen again. Not in this day and age".


title: The Boy in the Striped Pyjamas

text: "The Boy in The Striped Pyjamas" fits into the genre of Holocaust fiction. Boyne uses general knowledge about the Holocaust to create a self-described "fable", that relies more on a story of moral truth than historical accuracy. This type of literature, as shown in "The Boy in the Striped Pyjamas," tends to be told to children, from a child's perspective. By having one child share the "bitter herbs" of history with another, the novel instills moral obligation in children.


title: The Boy in the Striped Pyjamas

text: Kenneth Kidd, professor of English at the University of Florida, argues that John Boyne's use of fable allows him to explore the darker elements of the Holocaust with more of a cautionary tale resulting.


title: The Boy in the Striped Pyjamas

text: Sophie Melissa Smith, a PhD candidate at the University of Southampton, argues that writing a factual story as a fable is damaging as it may produce misconceptions about the Holocaust. Examples include the ability of Shmuel to escape work and Bruno's ability to approach an electrified fence.


title: The Boy in the Striped Pyjamas

text: Smith claims that Boyne lowers the culpability of Nazis like Bruno's father by not just humanizing them but also creating a sense of obligation in characters like Bruno's father, as Bruno's father was a Commandant at a large concentration camp. Additionally, the depiction of the story told through Bruno creates a greater ignorance of the Nazi regime by using words such as "the Fury" in place of the Fuhrer and "Out-with" in place of Auschwitz. Generally, critics see the trivialization of the Nazi regime in this portrayal as damaging to Holocaust education.


title: The Boy in the Striped Pyjamas

text: A 2009 study by the London Jewish Cultural Centre conducted a survey in which 75% of respondents thought Boyne's novel was based on a true story. Many students also thought "the tragic death of Bruno brought about the end of concentration camps."


title: The Boy in the Striped Pyjamas

text: Criticising the book's accuracy, the Auschwitz-Birkenau State Museum commented in 2020 that the novel "should be avoided by anyone who studies or teaches about the Holocaust." The Melbourne Holocaust Museum, while finding the book a powerful introduction to the subject, cautions teachers regarding its many inaccuracies.


title: The Boy in the Striped Pyjamas

text: Following on from their research in 2016, that suggested that pupils reach mistaken and/or misleading conclusions about the Holocaust from the book, The UCL Centre for Holocaust Education's 2020 research found that 35% of teachers in England conducting lessons on the Holocaust use it, or the film.


title: The Boy in the Striped Pyjamas

text: Kathryn Hughes, writing in "The Guardian", calls the novel "a small wonder of a book." She takes issue with the laxness of Auschwitz and describes the novel as "something that borders on fable," arguing that "Bruno's innocence comes to stand for the willful refusal of all adult Germans to see what was going on under their noses."


title: The Boy in the Striped Pyjamas

text: Nicholas Tucker, writing in "The Independent", calls the novel "a fine addition to a once taboo area of history, at least where children's literature is concerned." He asserts that it is a good depiction of a tragic event that strays away from graphic details, with the exception of the "killer punch" at the end of the novel.


title: The Boy in the Striped Pyjamas

text: Ed Wright, writing in "The Age" of Melbourne, calls the novel "a touching tale of an odd friendship between two boys in horrendous circumstances and a reminder of man's capacity for inhumanity." He felt that the depiction of Bruno and Shmuel's friendship was a classic childhood friendship with a naïvety of their surroundings. He concludes by observing that ""The Boy in the Striped Pyjamas" is subtitled "A Fable"", and sets out to create a moral story of human nature in a fable format.


title: The Boy in the Striped Pyjamas

text: A. O. Scott, writing in "The New York Times", questioned the author and publisher's choice to intentionally keep the Holocaust setting of the book vague in both the dust jacket summary and the early portion of the novel. Scott described how the experiences of the characters were supposed to be represented as separate from the setting of the Holocaust, and this creates a lack of the informative nature seen in other novels of Holocaust literature such as "Night" by Elie Wiesel. Scott claims that "there is something awkward about the way Boyne manages to disguise, and then to disclose, the historical context." Scott concludes that "to mold the Holocaust into an allegory, as Boyne does here with perfectly benign intent, is to step away from its reality."


title: The Boy in the Striped Pyjamas

text: Rabbi Benjamin Blech offered a historical criticism, contending that the premise of the book and subsequent film – that there could be a child of Shmuel's age in Auschwitz – was impossible, writing of the book: "Note to the reader: there were no 9-year-old Jewish boys in Auschwitz – the Nazis immediately gassed those not old enough to work." Rabbi Blech affirmed the opinion of a Holocaust survivor friend that the book is "not just a lie and not just a fairytale, but a profanation." Students who read it, he warns, may believe the camps "weren't that bad" if a boy could conduct a clandestine friendship with a Jewish captive of the same age, unaware of "the constant presence of death."


title: The Boy in the Striped Pyjamas

text: Holocaust scholar Henry Gonshak rebuts Blech's historical contention in his book, "Hollywood and the Holocaust". He writes that "the rabbi found implausible Shmuel's very existence in the camp," but states that "Blech is factually incorrect." While there were no female children, records have shown that in 1944 "there were 619 male children at the camp, ranging in age from one month to fourteen years old."


title: The Boy in the Striped Pyjamas

text: Gonshak acknowledges that this presence of children does not take away from the thousands who were killed in the gas chambers.


title: The Boy in the Striped Pyjamas

text: In 2008, two years after being published, the novel was made into a movie "The Boy in the Striped Pyjamas", directed by Mark Herman.


title: The Boy in the Striped Pyjamas

text: In 2017, the novel was adapted into a ballet by the Northern Ballet. The score is produced by Gary Yershon. Reviews of the ballet are generally negative with Zo and Euml Anderson of "The Independent" stating the casting of children's parts as adults works against "the naivety of a child's viewpoint," which the novel captures. "The Yorkshire Post"s review described the score as "a relentless assault on the ears," but apart from the music, it stated that it has redeemable quality in the cast, despite being depressing.


title: The Boy in the Striped Pyjamas

text: In 2023, the novel will be adapted into a 75-minute, two-act chamber opera entitled "A Child In Striped Pyjamas" by Noah Max. He says of Boyne's book: "It's very hard to convince children to read a book about something as dark and serious as the Holocaust and what I find amazing is that while not all adults get the profound symbolism of the story, kids get it. They pick up on the fact that the children have the same birthday and are the same child."


title: Olympic weightlifting

text: Olympic weightlifting, or Olympic-style weightlifting (officially named Weightlifting), is a sport in which athletes compete in lifting a barbell loaded with weight plates from the ground to overhead, with each athlete trying to successfully lift the heaviest weights. Athletes compete in two specific ways of lifting the barbell overhead: these are the snatch and the clean and jerk. The "snatch" is a wide-grip lift, in which the weighted barbell is lifted overhead in one motion. The "clean and jerk" is a combination lift, in which the weight is first taken from the ground to the front of the shoulders (the clean), and then from the shoulders to overhead (the jerk). The clean and press, wherein a clean was followed by an overhead press, was formerly also a competition lift, but was discontinued due to difficulties in judging proper form.


title: Olympic weightlifting

text: Each weightlifter gets three attempts at both the snatch and the clean and jerk, with the snatch attempts being done first. An athlete's score is the combined total of the highest successfully-lifted weight in kilograms for each lift. Athletes compete in various weight classes, which are different for each sex and have changed over time. Lifters who fail to successfully complete at least one snatch and at least one clean and jerk fail to "total", and receive an "incomplete" entry for the competition.


title: Olympic weightlifting

text: Weightlifting is an olympic sport, and has been contested in every Summer Olympic Games since 1920. Whilst the sport is officially named "weightlifting", the terms "olympic weightlifting" and "olympic-style weightlifting" are often used to distinguish it from the other sports and events that involve the lifting of weights, such as powerlifting, weight training, and strongman events. Similarly, the snatch and clean-and-jerk are known as the "olympic lifts".


title: Olympic weightlifting

text: While other strength sports test limit strength, olympic-style weightlifting also tests aspects of human ballistic limits (explosive strength): the olympic lifts are executed faster, and with more mobility and a greater range of motion during their execution, than other barbell lifts. The olympic lifts, and their component lifts (e.g., cleans, squats) and their variations (e.g., power snatch, power clean) are used by elite athletes in other sports to train for both explosive and functional strength.


title: Olympic weightlifting

text: The sport is controlled by the International Weightlifting Federation (IWF). Based in Budapest, it was founded in 1905.


title: Olympic weightlifting

text: The "snatch" is a lift wherein an athlete sweeps the barbell up and overhead in one continuous action: the lifter takes a wide-grip on the bar and pulls the barbell off the floor before rapidly re-bending their knees to get themself under the barbell (usually bringing themself into a deep overhead squat position), so that the barbell is supported over their head with arms outstretched. The "snatch" is then completed by the lifter rising to a standing position whilst holding the barbell overhead.


title: Olympic weightlifting

text: The "clean and jerk" is a combination lift, in which the athlete gets the barbell overhead in two stages: first by lifting the barbell into support on the front of the shoulders ("the clean"), and then lifting it from shoulders to overhead ("the jerk"). To perform the "clean", the lifter takes a shoulder-width grip on the bar and pulls it off the floor, and then rapidly re-bends their knees (and bends their arms) to get their body under the barbell and "catch" the bar on the front of the shoulders (usually in a deep front squat position). The lifter finishes the "clean" by rising to a standing position whilst holding the barbell on the front of their shoulders. The lifter then uses the "jerk" to jump into a bent knees position (usually with one foot forward and the other back - known as the "split jerk") whilst pumping the barbell overhead"." The "jerk" is completed when the lifter re-straightens the legs (bringing them together after a "split jerk") so they come to a straight standing position with the barbell held overhead.


title: Olympic weightlifting

text: The "clean and press", a competition lift from 1924 through 1972, entails a clean followed by an "overhead press". The "overhead press" is distinguished from the "jerk", in that jerking movements, bending of the legs, and displacement of the feet are prohibited.


title: Olympic weightlifting

text: Athletes compete in a division determined by their body mass. In summer 2018, the IWF approved the current weight categories, specifying which 7 of the 10 total would be contested at the 2020 Summer Olympics.


title: Olympic weightlifting

text: In each weight division, lifters compete in both the snatch and clean and jerk. Prizes are usually given for the heaviest weights lifted in each and in the overall—the maximum lifts of both added. The order of the competition is up to the lifters—the competitor who chooses to attempt the lowest weight goes first. If they are unsuccessful at that weight, they have the option of reattempting at that weight or trying a heavier weight after any other competitors have made attempts at the previous weight or any other intermediate weights. The barbell is loaded incrementally and progresses to a heavier weight throughout the course of competition. Weights are set in 1-kilogram increments. If two athletes lift the same weight, they are both credited with it but in terms of placing the one who lifted the weight first gets the highest placing.


title: Olympic weightlifting

text: During competition, the snatch event takes place first, followed by a short intermission, and then the clean and jerk event. There are two side judges and one head referee who together provide a "successful" or "failed" result for each attempt based on their observation of the lift within the governing body's rules and regulations. Two successes are required for any attempt to pass. Usually, the judges' and referee's results are registered via a lighting system with a white light indicating a "successful" lift and a red light indicating a "failed" lift. This is done for the benefit of all in attendance be they athlete, coach, administrator or audience. In addition, one or two technical officials may be present to advise during a ruling.


title: Olympic weightlifting

text: At local competitions, a "Best Lifter" title is commonly awarded. It is awarded to both the best men's and women's lifters. The award is based on a formula which employs the "Sinclair coefficient", a coefficient derived and approved by the sport's world governing body, which allows for differences in both gender and bodyweight. When the formula is applied to each lifter's overall total and then grouped along with the other competitors' and evaluated, it provides a numeric result which determines the competition's best overall men's and women's lifters. And while, usually, the winner of the heaviest weight class will have lifted the most overall weight during the course of a competition, a lifter in a lighter weight class may still have lifted more weight both relative to their own bodyweight, and to the Sinclair coefficient formula, thereby garnering the "Best Lifter" award.


title: Olympic weightlifting

text: The competition to establish who can lift the heaviest weight has been recorded throughout civilization, with the earliest known recordings including those found in Egypt, China, India, and Ancient Greece. Today, the modern sport of weightlifting traces its origins to the European competitions of the 19th century. The first male world champion was crowned in 1891; the weightlifters were not categorized by weight at this time, and a women's championship did not exist until 1987.


title: Olympic weightlifting

text: The first Olympic Games of 1896 included weightlifting in the Field event of the predecessor to today's track and field or athletics event. During the 1900 Olympic Games, there was no weightlifting event. Weightlifting resumed as an event, again in athletics, in 1904 but was omitted from the Games of 1908 and 1912. These were the last Games until after the First World War. In these early Games, a distinction was drawn between lifting with 'one hand' only and lifting with 'two hands'. The winner of the 'one hand' competition in 1896 was Launceston Elliot of Scotland, while the winner of the 'two hands' event was Viggo Jensen of Denmark.


title: Olympic weightlifting

text: In 1920, weightlifting returned to the Olympics and, for the first time, as an event in its own right. At these Games, which took place in Antwerp, Belgium, fourteen nations competed. The competition lifts were the 'one hand' snatch, the 'one hand' clean and jerk and the 'two hands' clean and jerk. At the next Olympic Games, in Paris, France, in 1924, the 'two hands' press and the 'two hands' snatch were added to the program, making a total of five lifts.


title: Olympic weightlifting

text: In the Olympic Games after 1920, instead of requiring all competitors to compete against each other regardless of size, weight classes were introduced and, by the 1932 Olympic Games, weightlifting was divided into five weight divisions.


title: Olympic weightlifting

text: In 1928, the sport dropped the 'one hand' exercises altogether, leaving only the three remaining exercises: the clean and press, the snatch, and the clean and jerk.


title: Olympic weightlifting

text: After the 1972 Olympics, the clean and press were removed from the program due to difficulties in judging the event. Athletes had begun utilizing their hips and leaning backward substantially rather than "strictly" pressing the weight overhead with an upright torso. Once the weight had been cleaned to the shoulders, the press was commonly achieved with a "double layback," starting with a rapid hip thrust to generate upward momentum at the shoulders, followed by a second, more extreme form of the same movement to lower the shoulders again as the bar traveled upwards, before finally, the lifter recovered to an upright position with the bar overhead. Some athletes were able to initiate the press with a hip thrust so rapid that judges found it difficult to determine whether or not they had utilized any knee bend to generate additional force, something strictly prohibited in the rules. "Excessive layback" was also prohibited, but it was considered too difficult to determine what degree of layback constituted a rule violation. As a result, the clean and press were discontinued, and what remained were the two elements of the modern Olympic weightlifting program—the snatch and the clean and jerk. The snatch consists of lifting the barbell from the floor to an overhead position in one fluid motion. It is an exact lift that can be nullified by a lack of balance of the athlete. The clean and jerk consists of moving the barbell from the floor to overhead in 2 movements: from the floor to the shoulders, and from the shoulders to overhead.


title: Olympic weightlifting

text: As early as 1986, there were official world championships awarded to women weightlifters such as Karyn Marshall and Judy Glenney. However, it was not until the 2000 Olympic Games in Sydney, Australia that an official Olympic competition for women was introduced. Since the Olympic weightlifting competition for women was established, China's Chen Yanqing and Liu Chunhong have each earned two gold medals.


title: Olympic weightlifting

text: In 2011, the International Weightlifting Federation ruled that athletes could wear a full body "unitard" under the customary weightlifting uniform. Kulsoom Abdullah became the first woman to do so at the U.S. National Championships that year, and athletes are allowed to do so at the Olympics. IWF rules previously stated that an athlete's knees and elbows must be visible so officials can determine if a lift is correctly executed.


title: Olympic weightlifting

text: Olympic weightlifting uses a steel bar (also known as a barbell) with larger-diameter rotating sleeves on either end, holding rubber-coated weight plates of different weights. This sleeve rotation is important for the Olympic lifts, particularly the snatch and clean movements, because it drastically reduces the rotational inertia of the bar. Without sleeve rotation, the Olympic lifter faces more challenging lifts and a greater risk of injury.


title: Olympic weightlifting

text: A men's Olympic barbell weighs 20 kg (44 lbs) with a shaft diameter of 28 mm and a length of 2200 mm, whereas a women's Olympic barbell weighs 15 kg (33 lbs) and has a shaft diameter of 25 mm with a length of 2010 mm. The distance between the sleeves, however, is the same for the men's and the women's bars at 1310 mm. The grip texture of the bar is called the knurling, and is distributed differently between the men's and women's bars: the men's has knurling in the center but the women's does not. The Olympic barbells used in competition are certified by the IWF.


title: Olympic weightlifting

text: The weight plates, typically referred to as "bumper plates" because of their rubber coated design, weigh between 10 kg and 25 kg in 5 kg increments. The bumper plates are coated with rubber to allow the weights to be dropped from various heights—either after a successful lift or during an unsuccessful one. Olympic bumper plates conform to international standards for coloring. That is, 10 kg is green, 15 kg is yellow, 20 kg is blue, and 25 kg is red.


title: Olympic weightlifting

text: In addition to the rubber bumpers, smaller competition iron plates can be used to add weight in small increments to the bar. The color designations for these iron plates are as follows: 1 kg is green, 1.5 kg is yellow, 2 kg is blue, 2.5 kg is red, 5 kg and 0.5 kg are white. It is useful to note the color assignment of these iron plates is consistent with the heavier bumper plates (i.e. 1 kg and 10 kg are green, 1.5 kg and 15 kg are yellow, etc.).


title: Olympic weightlifting

text: Lifters typically wear a one-piece close-fitting leotard often called a singlet. The wearing of a T-shirt underneath the singlet is optional.


title: Olympic weightlifting

text: Chalk is regularly used by Olympic lifters, generally prior to each attempt at a lift. Lifters rub their hands with the chalk to promote dryness and prevent the bar moving in their hands.


title: Olympic weightlifting

text: Olympic lifters frequently use tape to cover the areas of their bodies exposed to friction while completing Olympic lifts. Tape is most commonly found on the Olympic lifter's thumb. A taped thumb not only lessens the risk of calluses, but it also reduces the pain associated with the hook grip.


title: Olympic weightlifting

text: Olympic lifters also tape their wrists, preventing exaggerated and uncomfortable joint movement during lifts. For particularly heavy overhead lifts, a taped wrist enables the lifter to regulate wrist extension and delimit the translation of the radius and ulna distal heads. However, while taped wrists can prevent wrist and forearm injuries in the short-term, excessive use can lead to weakened connective tissue in the area, increasing the risk of pain and injury.


title: Olympic weightlifting

text: The type of shoes worn by Olympic weightlifters is perhaps their most distinctive piece of equipment. Weightlifting shoes are typically designed with a raised heel of 0.5" to 1.5" and one or two metatarsal straps that tighten across the instep of the shoe. The raised heel helps the lifter maintain an upright torso while catching the bar and also allows for a deeper squat under the bar. The soles of the shoes are also quite rigid, helping to resist compression while under heavy loads. The shoes are designed for maximum stability while remaining flexible in the toe box. This allows the lifter to come up on the toes and to catch the weight on the ball of the back foot during the "jerk" movement of the lift.


title: Mind map

text: A mind map is a diagram used to visually organize information into a hierarchy, showing relationships among pieces of the whole. It is often created around a single concept, drawn as an image in the center of a blank page, to which associated representations of ideas such as images, words and parts of words are added. Major ideas are connected directly to the central concept, and other ideas branch out from those major ideas.


title: Mind map

text: Mind maps can also be drawn by hand, either as "notes" during a lecture, meeting or planning session, for example, or as higher quality pictures when more time is available. Mind maps are considered to be a type of spider diagram.


title: Mind map

text: Although the term "mind map" was first popularized by British popular psychology author and television personality Tony Buzan, the use of diagrams that visually "map" information using branching and radial maps traces back centuries. These pictorial methods record knowledge and model systems, and have a long history in learning, brainstorming, memory, visual thinking, and problem solving by educators, engineers, psychologists, and others. Some of the earliest examples of such graphical records were developed by Porphyry of Tyros, a noted thinker of the 3rd century, as he graphically visualized the concept categories of Aristotle. Philosopher Ramon Llull (1235–1315) also used such techniques.


title: Mind map

text: Buzan's specific approach, and the introduction of the term "mind map", started with a 1974 BBC TV series he hosted, called "Use Your Head". In this show, and companion book series, Buzan promoted his conception of radial tree, diagramming key words in a colorful, radiant, tree-like structure.


title: Mind map

text: Cunningham (2005) conducted a user study in which 80% of the students thought "mindmapping helped them understand concepts and ideas in science". Other studies also report some subjective positive effects on the use of mind maps. Positive opinions on their effectiveness, however, were much more prominent among students of art and design than in students of computer and information technology, with 62.5% vs 34% (respectively) agreeing that they were able to understand concepts better with mind mapping software. Farrand, Hussain, and Hennessy (2002) found that spider diagrams (similar to concept maps) had limited, but significant, impact on memory recall in undergraduate students (a 10% increase over baseline for a 600-word text only) as compared to preferred study methods (a 6% increase over baseline). This improvement was only robust after a week for those in the diagram group and there was a significant decrease in motivation compared to the subjects' preferred methods of note taking. A meta study about concept mapping concluded that concept mapping is more effective than "reading text passages, attending lectures, and participating in class discussions". The same study also concluded that concept mapping is slightly more effective "than other constructive activities such as writing summaries and outlines". However, results were inconsistent, with the authors noting "significant heterogeneity was found in most subsets". In addition, they concluded that low-ability students may benefit more from mind mapping than high-ability students.


title: Mind map

text: Joeran Beel and Stefan Langer conducted a comprehensive analysis of the content of mind maps. They analysed 19,379 mind maps from 11,179 users of the mind mapping applications (now ) and MindMeister. Results include that average users create only a few mind maps (mean=2.7), average mind maps are rather small (31 nodes) with each node containing about three words (median). However, there were exceptions. One user created more than 200 mind maps, the largest mind map consisted of more than 50,000 nodes and the largest node contained ~7,500 words. The study also showed that between different mind mapping applications (Docear vs MindMeister) significant differences exist related to how users create mind maps.


title: Mind map

text: There have been some attempts to create mind maps automatically. Brucks & Schommer created mind maps automatically from full-text streams. Rothenberger et al. extracted the main story of a text and presented it as mind map. There is also a patent application about automatically creating sub-topics in mind maps.


title: Mind map

text: Mind-mapping software can be used to organize large amounts of information, combining spatial organization, dynamic hierarchical structuring and node folding. Software packages can extend the concept of mind-mapping by allowing individuals to map more than thoughts and ideas with information on their computers and the Internet, like spreadsheets, documents, Internet sites, images and videos. It has been suggested that mind-mapping can improve learning/study efficiency up to 15% over conventional note-taking.


title: Mind map

text: The following dozen examples of mind maps show the range of styles that a mind map may take, from hand-drawn to computer-generated and from mostly text to highly illustrated. Despite their stylistic differences, all of the examples share a tree structure that hierarchically connects sub-topics to a main topic.


title: Parallax

text: Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects show a larger parallax than farther objects when observed from different positions, so parallax can be used to determine distances.


title: Parallax

text: To measure large distances, such as the distance of a planet or a star from Earth, astronomers use the principle of parallax. Here, the term "parallax" is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder.


title: Parallax

text: Parallax also affects optical instruments such as rifle scopes, binoculars, microscopes, and twin-lens reflex cameras that view objects from slightly different angles. Many animals, along with humans, have two eyes with overlapping visual fields that use parallax to gain depth perception; this process is known as stereopsis. In computer vision the effect is used for computer stereo vision, and there is a device called a parallax rangefinder that uses it to find the range, and in some variations also altitude to a target.


title: Parallax

text: A simple everyday example of parallax can be seen in the dashboards of motor vehicles that use a needle-style mechanical speedometer. When viewed from directly in front, the speed may show exactly 60, but when viewed from the passenger seat, the needle may appear to show a slightly different speed due to the angle of viewing combined with the displacement of the needle from the plane of the numerical dial.


title: Parallax

text: As the eyes of humans and other animals are in different positions on the head, they present different views simultaneously. This is the basis of stereopsis, the process by which the brain exploits the parallax due to the different views from the eye to gain depth perception and estimate distances to objects. Animals also use "motion parallax", in which the animals (or just the head) move to gain different viewpoints. For example, pigeons (whose eyes do not have overlapping fields of view and thus cannot use stereopsis) bob their heads up and down to see depth.


title: Parallax

text: The motion parallax is exploited also in wiggle stereoscopy, computer graphics that provide depth cues through viewpoint-shifting animation rather than through binocular vision.


title: Parallax

text: Parallax arises due to a change in viewpoint occurring due to the motion of the observer, of the observed, or both. What is essential is relative motion. By observing parallax, measuring angles, and using geometry, one can determine distance.


title: Parallax

text: Stellar parallax created by the relative motion between the Earth and a star can be seen, in the Copernican model, as arising from the orbit of the Earth around the Sun: the star only "appears" to move relative to more distant objects in the sky. In a geostatic model, the movement of the star would have to be taken as "real" with the star oscillating across the sky with respect to the background stars.


title: Parallax

text: Stellar parallax is most often measured using annual parallax, defined as the difference in position of a star as seen from the Earth and Sun, i.e. the angle subtended at a star by the mean radius of the Earth's orbit around the Sun. The parsec (3.26 light-years) is defined as the distance for which the annual parallax is 1 arcsecond. Annual parallax is normally measured by observing the position of a star at different times of the year as the Earth moves through its orbit. Measurement of annual parallax was the first reliable way to determine the distances to the closest stars. The first successful measurements of stellar parallax were made by Friedrich Bessel in 1838 for the star 61  Cygni using a heliometer. Stellar parallax remains the standard for calibrating other measurement methods. Accurate calculations of distance based on stellar parallax require a measurement of the distance from the Earth to the Sun, now based on radar reflection off the surfaces of planets.


title: Parallax

text: The angles involved in these calculations are very small and thus difficult to measure. The nearest star to the Sun (and thus the star with the largest parallax), Proxima Centauri, has a parallax of 0.7687 ± 0.0003  arcsec. This angle is approximate that subtended by an object 2 centimeters in diameter located 5.3 kilometers away.


title: Parallax

text: The fact that stellar parallax was so small that it was unobservable at the time was used as the main scientific argument against heliocentrism during the early modern age. It is clear from Euclid's geometry that the effect would be undetectable if the stars were far enough away, but for various reasons such gigantic distances involved seemed entirely implausible: it was one of Tycho's principal objections to Copernican heliocentrism that for it to be compatible with the lack of observable stellar parallax, there would have to be an enormous and unlikely void between the orbit of Saturn (then the most distant known planet) and the eighth sphere (the fixed stars).


title: Parallax

text: In 1989, the satellite Hipparcos was launched primarily for obtaining improved parallaxes and proper motions for over 100,000 nearby stars, increasing the reach of the method tenfold. Even so, Hipparcos was only able to measure parallax angles for stars up to about 1,600 light-years away, a little more than one percent of the diameter of the Milky Way Galaxy. The European Space Agency's Gaia mission, launched in December 2013, can measure parallax angles to an accuracy of 10 microarcseconds, thus mapping nearby stars (and potentially planets) up to a distance of tens of thousands of light-years from Earth. In April 2014, NASA astronomers reported that the Hubble Space Telescope, by using spatial scanning, can precisely measure distances up to 10,000 light-years away, a ten-fold improvement over earlier measurements.


title: Parallax

text: Distance measurement by parallax is a special case of the principle of triangulation, which states that one can solve for all the sides and angles in a network of triangles if, in addition to all the angles in the network, the length of at least one side has been measured. Thus, the careful measurement of the length of one baseline can fix the scale of an entire triangulation network. In parallax, the triangle is extremely long and narrow, and by measuring both its shortest side (the motion of the observer) and the small top angle (always less than 1 arcsecond, leaving the other two close to 90  degrees), the length of the long sides (in practice considered to be equal) can be determined.