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Casa Milà

Casa Milà, popularly known as La Pedrera (, ; "the stone quarry") in reference to its unconventional rough-hewn appearance, is a Modernista building in Barcelona, Catalonia, Spain. It was the last private residence designed by architect Antoni Gaudí and was built between 1906 and 1912.

The building was commissioned in 1906 by and his wife. At the time, it was controversial because of its undulating stone facade, twisting wrought iron balconies, and design by Josep Maria Jujol. Several structural innovations include a self-supporting stone façade, and a free-plan floor, underground garage and the spectacular terrace on the roof.

In 1984, it was declared a World Heritage Site by UNESCO. Since 2013 it has been the headquarters of the Fundació Catalunya La Pedrera, which manages visits to the building, exhibitions and other cultural and educational activities at Casa Milà.

Architect
Antoni Gaudí i Cornet was born on June 25, 1852, in Catalonia, Spain. As a child, Gaudí's health was poor, suffering from rheumatism. Because of this, he was afforded lengthy periods of time resting at his summer house in Riudoms. Here he spent a large portion of his time outdoors, allowing him to deeply study nature. This would become one of the major influences in his architecture to come.

Gaudí was a very practical man and a craftsman at his core. In his work he followed impulses and turned creative plans into reality. His openness to embrace new styles combined with a vivid imagination helped mold new styles of architecture and consequently helped push the limits of construction. Today he is regarded as a pioneer of the modern architecture style.

In 1870, Gaudí moved to Barcelona to study architecture. He was an inconsistent student who showed flashes of brilliance. It took him eight years to graduate due to a mix of health complications, military service as well as other activities.

After completion of his education he became a prolific architect as well as designing gardens, sculptures and all other decorative arts. Gaudí's most famous works consisted of several buildings: Parque Güell; Palacio Güell; Casa Mila; Casa Vicens. He also is attributed for his work on the Crypt of La Sagrada Familia and the Nativity facade. Gaudí's work at the time was both admired and criticized for his bold, innovative solutions.

Gaudí was injured on June 7, 1926, when he was run over by a tram. He later died in the hospital due to his injuries on June 10, 1926, at the age of 73. A few years after his death, his fame became renowned by critics and the general public alike.

Building owners
Casa Milà was built for Roser Segimón and her husband Pere Milà. Roser Segimón was the wealthy widow of Josep Guardiola, an Indiano or Americano, or former colonist returned from the Americas, who had made his fortune with a coffee plantation in Guatemala. Her second husband, Pere Milà, was a developer known for his flamboyant lifestyle.

Construction process
In 1905, Milà and Segimón married and on June 9, Roser Segimón bought a house with garden which occupied an area of 1,835 square meters, located on Paseo de Gracia, 92. In September, they commissioned Gaudí for building them a new house with the idea of living in the main floor and renting out the rest of the apartments. On February 2, 1906, the project was presented to the Barcelona City Council and the works began, demolishing the pre-existing building instead of reforming it, as in the case of the Casa Batlló.

The building was completed in December 1910 and the owner asked Gaudí to make a certificate to inhabit the main floor, which the City Council authorized in October 1911, and the couple moved in. On October 31, 1912, Gaudí issued the certificate stating that, in accordance with his plans and his direction, the work had been completed and the whole house was ready to be rented.

Critics and controversies
The building did not respect any rules of conventional style, for which Gaudí received much criticism. To begin with, the name "La Pedrera" is in fact a nickname assigned by the citizens who disapproved of its unusualness. The unique structure of the building and the relationship between the building's architect and Pere Milà became the object of ridicule for the people of Barcelona and many humorous publications of the time.

Catholic symbols
Gaudí, a Catholic and a devotee of the Virgin Mary, planned for the Casa Milà to be a spiritual symbol. Overt religious elements include an excerpt from the Rosary on the cornice and planned statues of Mary, specifically Our Lady of the Rosary, and two archangels, St. Michael and St. Gabriel.

However, the Casa Milà was not built entirely to Gaudí's specifications. The local government ordered the demolition of elements that exceeded the height standard for the city, and fined the Milàs for many infractions of building codes. After Semana Trágica, an outbreak of anticlericalism in the city, Milà prudently decided to forgo the religious statues. Gaudí contemplated abandoning the project but a priest persuaded him to continue.

Change of ownership
In 1940, Milà died. Segimon sold the property in 1946 for 18 million pesetas to Josep Ballvé i Pellisé, known for his department stores on, in partnership with the family of Pío Rubert Laporta. The Compañía Inmobiliaria Provenza, SA (CIPSA) was founded to administer the building. Roser Segimon continued to live on the main floor until her death in 1964.

The new owners divided the first floor facing into five apartments instead of the original two. In 1953, they commissioned to convert 13 rubbish-filled attic laundry rooms to street-facing apartments, leaving a communal hallway on the side facing the courtyards. Some of these two or three room apartments had a loft and were designed and furnished in a typical early 1950s style using brick, ceramic and wood. Items of furniture, such as the, were reminiscent of Eero Saarinen's work.

The insurance company Northern took over the main floor in 1966. By then, Casa Milà had housed a bingo hall, an academy and the offices of Cementos Molins and Inoxcrom among others. Maintenance costs were high and the owners had allowed the building to become dilapidated, causing stones to loosen in 1971. Josep Anton Comas made some emergency repairs, especially to the paintings in the courtyards, while respecting the original design.

Restoration
Gaudí's work was designated a historic and artistic monument on July 24, 1969. Casa Milà was in poor condition in the early 1980s. It had been painted a dreary brown and many of its interior color schemes had been abandoned or allowed to deteriorate, but it has been restored since and many of the original colors revived.

In 1984, the building became part of a World Heritage Site encompassing some of Gaudí's works. The Barcelonan city council tried to rent the main floor as an office for the 1992 Olympic bid. Finally, the day before Christmas 1986, Caixa Catalunya bought La Pedrera for 900 million pesetas. On February 19, 1987, urgently needed work began on the restoration and cleaning of the façade. The work was done by the architects Joseph Emilio Hernández-Cros and Rafael Vila. The renovated main floor opened in 1990 as part of the Cultural Olympiad of Barcelona. The floor became an exhibition room with an example of modernism in the Eixample.

Design
The building is 1,323 m2 per floor on a plot of 1,620 m2. Gaudí made the first sketches in his workshop in the Sagrada Família. He designed the house as a constant curve, both outside and inside, incorporating ruled geometry and naturalistic elements.

Casa Milà consists of two buildings, which are structured around two courtyards that provide light to the nine stories: basement, ground floor, mezzanine, main (or noble) floor, four upper floors, and an attic. The basement was intended to be the garage, the main floor the residence of the Milàs (a flat of all 1,323 m2), and the rest distributed over 20 apartments. The resulting layout is shaped like an asymmetrical "8" because of the different shapes and sizes of the courtyards. The attic housed the laundry and drying areas, forming an insulating space for the building and simultaneously determining the levels of the roof.

One of the most notable elements of the building is the roof, crowned with skylights, staircase exits, fans, and chimneys. All of these elements, constructed out of brick covered with lime, broken marble, or glass have a specific architectural function but are also real sculptures integrated into the building.

The apartments feature plastered ceilings with dynamic reliefs, handcrafted wooden doors, windows, and furniture, as well as hydraulic tiles and various ornamental elements.

The stairways were intended as service entries, with the main access to the apartments by elevator except for the noble floor, where Gaudí added a prominent interior staircase. Gaudí wanted the people who lived in the flats to all know each other. Therefore, there were only elevators on every other floor, so people on different floors would meet one another.

Structure
Casa Milà is characterized by its self-supporting stone facade, meaning that it is free of load-bearing walls. The facade connects to the internal structure of each floor by means of curved iron beams surrounding the perimeter of each floor. This construction system allows, on one hand, large openings in the facade which give light to the homes, and on the other, free structuring of the different levels, so that internal walls can be added and demolished without affecting the stability of the building. This allows the owners to change their minds at will and to modify, without problems, the interior layout of the homes.

Facade
The facade is composed of large blocks of limestone from the Garraf Massif on the first floor and from the Villefranche quarry for the higher levels. The blocks were cut to follow the plot of the projection of the model, then raised to their location and adjusted to align in a continuous curve to the pieces around them.

The windows of La Pedrera are an integral part of the overall facade design. Gaudí made sure that the windows were of varying sizes, designed to optimize the amount of natural light that could enter the building.

Viewed from the outside the building has three parts: the main body of the six-storey blocks with winding stone floors, two floors set a block back with a different curve, similar to waves, a smoother texture and whiter color, and with small holes that look like embrasures, and finally the body of the roof.

Gaudí's original facade had some of its lower-level ironwork removed. In 1928, the tailor Mosella opened the first store in La Pedrera, and he eliminated the bars. This did not concern anyone, because in the middle of twentieth century, wrought ironwork had little importance. The ironwork was lost until a few years later, when Americans donated one of them to the MoMa, where it is on display.

With restoration initiatives launched in 1987, the facade was rejoined to some pieces of stone that had fallen. In order to respect the fidelity of the original, material was obtained from the Villefranche quarry, even though by then it was no longer operating.

Hall and courtyards
The building uses a completely original solution to solve the issue of a lobby being too closed and dark. Its open and airy courtyards provide a place of transit and are directly visible to those accessing the building. There are two patios on the side of the Passeig de Gracia and of the street Provence.

Patios, structurally, are key as supporting loads of interior facades. The floor of the courtyard is supported by pillars of cast iron. In the courtyard, there are traditional elliptical beams and girders but Gaudí applied an ingenious solution of using two concentric cylindrical beams with stretched radial beams, like the spokes of a bicycle. They form a point outside of the beam to two points above and below, making the function of the central girder a keystone and working in tension and compression simultaneously. This supported structure is twelve feet in diameter and is considered "the soul of the building" with a clear resemblance to Gothic crypts. The centerpiece was built in a shipyard by Josep Maria Carandell who copied a steering wheel, interpreting Gaudí's intent as to represent the helm of the ship of life.
 * Patios

Access is protected by a massive iron gate with a design attributed to Jujol. It was originally used by both people and cars, as access to the garage is in the basement, now an auditorium.
 * Interior, gates

The two halls are fully polychrome with oil paintings on the plaster surfaces, with eclectic references to mythology and flowers.

During construction there was a problem including a basement as a garage for cars, the new invention that was thrilling the bourgeois at the time. The future neighbor Felix Anthony Meadows, owner of Industrial Linera, requested a change because his Rolls-Royce could not access it. Gaudí agreed to remove a pillar on the ramp that led into the garage so that Felix, who was establishing sales and factory in Parets del Vallès, could go to both places with his car from La Pedrera.

For the floors of Casa Milà, Gaudí used a model of floor forms of square timbers with two colors, and the hydraulic pavement hexagonal pieces of blue and sea motifs that had originally been designed for the Batllo house. The wax was designed in gray by John Bertrand under the supervision of Gaudí who "touched up with their own fingers," in the words of the manufacturer Josep Bay.

Loft
Like in Casa Batlló, Gaudí shows the application of the catenary arch as a support structure for the roof, a form which he had already used shortly after graduating in the wood frameworks of Mataró's cooperative known as "L'Obrera Mataronense." In this case, Gaudí used the Catalan technique of timbrel, imported from Italy in the fourteenth century.

The attic, where the laundry rooms were located, was a clear room under a Catalan vault roof supported by 270 parabolic vaults of different heights and spaced by about 80 cm. The roof resembles both the ribs of a huge animal and a palm, giving the roof-deck a very unconventional shape similar to a landscape of hills and valleys. The shape and location of the courtyards makes the arches higher when the space is narrowed and lower when the space expands.

The builder Bayó explained its construction: "First the face of a wide wall was filled with mortar and plastered. Then Canaleta indicated the opening of each arch and Bayó put a nail at each starting point of the arch at the top of the wall. From these nails was dangled a chain so that the lowest point coincided with the deflection of the arch. Then the profile displayed on the wall by the chain was drawn and on this profile the carpenter marked and placed the corresponding centering, and the timbrel vault was started with three rows of plane bricks. Gaudí wanted to add a longitudinal axis of bricks connecting all vaults at their keystones".

Roof and chimneys
The work of Gaudí on the rooftop of La Pedrera brought his experience at Palau Güell together with solutions that were clearly more innovative – this time creating shapes and volumes with more body, more prominence, and less polychromasia.

On the rooftop there are six skylights/staircase exits (four of which were covered with broken pottery and some that ended in a double cross typical of Gaudí), twenty-eight chimneys in several groupings, two half-hidden vents whose function is to renew the air in the building, and four domes that discharged to the facade. The staircases also house the water tanks; some of which are snail-shaped.

The stepped roof of La Pedrera, called "the garden of warriors" by the poet Pere Gimferrer because the chimneys appear to be protecting the skylights, has undergone a radical restoration, removing chimneys added in interventions after Gaudí, television antennas, and other elements that degraded the space. The restoration brought back the splendor to the chimneys and the skylights that were covered with fragments of marble and broken Valencia tiles. One of the chimneys was topped with glass pieces – it was said that Gaudí did that the day after the inauguration of the building, taking advantage of the empty bottles from the party. It was restored with the bases of champagne bottles from the early twentieth century. The repair work has enabled the restoration of the original impact of the overhangs made of stone from Ulldecona with fragments of tiles. This whole set is more colorful than the facade, although here the creamy tones are dominant.

Furniture
Gaudí, as he had done in Casa Batlló, designed furniture specifically for the main floor. This was part of the concept artwork itself integral to modernism in which the architect assumed responsibility for global issues such as the structure and the facade, as well as every detail of the decor, designing furniture and accessories such as lamps, planters, floors or ceilings.

This was another point of friction with Segimon, who complained that there was no straight wall to place her Steinway piano. Gaudí's response was blunt: "So play the violin." The result of these disagreements has been the loss of the decorative legacy of Gaudí, as most of the furniture was removed due to climate change and the changes she made to the main floor when Gaudí died. Some remain in private collections, including a curtain made of oak 4 m. long by 1.96 m. high in the Museum of Catalan Modernism; and a chair and desktop of Milà.

Gaudí carved oak doors similar to what he had done for the Casa y Bardes, but these were only included on two floors as when Segimon discovered the price, she decided there would be no more at that quality.

Architecture
Casa Milà is part of the UNESCO World Heritage Site "Works of Antoni Gaudí". It was a predecessor of some buildings with a similar biomorphic appearance:
 * the 1921 Einstein Tower in Potsdam, designed by Erich Mendelsohn
 * Solomon R. Guggenheim Museum in Manhattan, New York, designed by Frank Lloyd Wright
 * Chapelle Notre Dame du Haut, Ronchamp, France, designed by Le Corbusier
 * the Hundertwasserhaus and other works by Austrian architect Friedensreich Hundertwasser
 * Disney Concert Hall in Los Angeles, by Frank Gehry

Free exhibitions often are held on the first floor, which also provides some opportunity to see the interior design. There is a charge for entrance to the apartment on the fourth floor and the roof. The other floors are not open to visitors.

Constructive similarities
Gaudí's La Pedrera was inspired by a mountain, but there is no agreement as to which mountain was the reference model. Joan Bergós thought it was the rocks of Fray Guerau in Prades mountains. Joan Matamala thought that the model could have been St. Miquel del Fai, while the sculptor Vicente Vilarubias believed it was inspired by the cliffs Torrent Pareis in Menorca. Other options include the mountains of Uçhisar in Cappadocia, suggested by Juan Goytisolo, or Mola Gallifa, suggested by Louis Permanyer, based on the fact that Gaudí visited the area in 1885 to escape an outbreak of cholera in Barcelona.

Some people say that the interior layout of La Pedrera comes from studies that Gaudí made of medieval fortresses. This image is reinforced by the seeming appearance of the rooftop chimneys as "sentinels" with great helmets. The structure of the iron door in the lobby does not follow any symmetry, straight or repetitive pattern. Rather, it evokes bubbles of soap that are formed between the hands or the structures of a plant cell.

Criticism and controversy
The building's unconventional style made it the subject of much criticism. It was given the nickname "La Pedrera", meaning "the quarry". Casa Milà appeared in many satirical magazines. Joan Junceda presented it as a traditional "Easter cake" by means of cartoons in Patufet. Joaquim Garcia made a joke about the difficulty of setting the damask wrought iron balconies in his magazine. Homeowners in Passeig de Gracia became angry with Milà and ceased to greet him, arguing that the weird building by Gaudí would lower the price of land in the area.

Administrative problems
Casa Milà also caused some administrative problems. In December 1907 the City Hall stopped work on the building because of a pillar which occupied part of the sidewalk, not respecting the alignment of facades. Again on August 17, 1908, more problems occurred when the building surpassed the predicted height and borders of its construction site by 4000 m2. The Council called for a fine of 100,000 pesetas (approximately 25% of the cost of work) or for the demolition of the attic and roof. The dispute was resolved a year and a half later, December 28, 1909, when the Commission certified that it was a monumental building and thus not required to have a 'strict compliance' with the bylaws.

Design competitions
The owner entered La Pedrera in the annual sponsored by the Barcelona City Council (Ayuntament). Other entries in the competition included two works by Sagnier (Calle Mallorca 264, and one on Corsica and Av. Diagonal), the Casa Gustà by architect, and the Casa Pérez Samanillo, designed by. Although the most dramatic and clear favorite was Casa Milà, the jury opined that even though the facades were complete, "there's still a lot left to do before it's fully completed, finalized and in a perfect state of appreciation." The winner in 1910 was Samanillo Perez, for his building which now houses the headquarters of the Circulo Ecuestre.

Design disagreements
Gaudí's relations with Segimon deteriorated during the construction and decoration of the house. There were many disagreements between them, one example being the monumental bronze virgin del Rosario, which Gaudí wanted as the statue on the front of the building in homage to the name of the owner, that the artist Carles Mani i Roig was to sculpt. The statue was not made although the words "Ave gratia M plena Dominus tecum" were written at the top of the facade. Continuing disagreements led Gaudí to take Milà to court over his fees. The lawsuit was won by Gaudí in 1916, and he gave the 105,000 pesetas he won in the case to charity, stating that "the principles mattered more than money." Milà was having to pay the mortgage.

After Gaudí's death in 1926, Segimon got rid of most of the furniture that Gaudí had designed and covered over parts of Gaudí's designs with new decorations in the style of Louis XVI. La Pedrera was acquired in 1986 by Caixa Catalunya and when restoration was done four years later, some of the original decorations re-emerged.

When the Civil War broke out in July 1936, the Milàs were on vacation. Part of the building was collectivized by the Unified Socialist Party of Catalonia; the Milàs fled the area with some artwork.

In media and literature

 * A scene in The Passenger (Italian: Professione: reporter), a film directed by Michelangelo Antonioni and starring Jack Nicholson and Maria Schneider, was filmed on the roof of the building.
 * A scene filmed on the roof in Vicky Cristina Barcelona, directed by Woody Allen.
 * A major part in the story "A murderer is born" in the novel Seiobo There Below by László Krasznahorkai happens here
 * Mentioned in the book by Eoin Colfer: Artemis Fowl and the Lost Colony
 * Mentioned in the book by Trudi Alexy 'The Mezuzah in the Madonna's Foot'
 * Mentioned in the 'Ballrooms and Biscotti' episode (season 4, episode 1) of Gilmore Girls
 * Several scenes in the movie, Gaudi Afternoon
 * A scale model exhibited at the Catalunya en Miniatura park.
 * Featured in the music video for Deep Forest's 'Sweet Lullaby'
 * The home of Edmond Kirsch in Dan Brown's novel Origin, the 5th book featuring Robert Langdon.

title: Casa Milà


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Talk:Aircraft

Aerodyne and Aerostat
The article doesn't explain the terms aerodyne and aerostat (sp?); I guess maybe the difference is analogous to the difference between dynamic and static stability in control theory? -- the dynamic version only achieves lift dynamically, but the latter version has lift statically, or intrinsically? Pagan 09:50, 30 Dec 2003 (UTC)

Link suggestions
An automated Wikipedia link suggester has some possible wiki link suggestions for the Aircraft article, and they have been placed on this page for your convenience. Tip: Some people find it helpful if these suggestions are shown on this talk page, rather than on another page. To do this, just add to this page. — LinkBot 10:29, 17 Dec 2004 (UTC)

Flight altitude records
Create a list for aircraft flight altitude records.

manned, crewed or what?
Somebody just change every instance of "manned" to "crewed". I reverted it because, while gender equality is very laudable, the choice of alternative is technically wrong. Manned flight includes passenger-only flights, such as that of Cayley's first glider, "manned" by a boy. Per WP:COMMONNAME it also traditionally includes flights by the equally politically incorrect aviatrix, such as Amelia Earhart or Amy Johnson. let us perhaps recall that Homo sapiens, Latin for "Wise man", nowadays includes the female of the species. The sum of crew and passengers is known as the aircraft's "complement". But no biologist is seeking to reclassify us as Complementum sapiens or any such neutral euphemism. Can we please maintain technical correctness, readability and common usage here, and avoid transparent euphemisms? — Cheers, Steelpillow (Talk) 19:57, 23 August 2023 (UTC)

 * Concur. In many cases, including this one, the WP:GNL essay violates guidelines, such as MOS:NEO. BilCat (talk) 22:25, 23 August 2023 (UTC)
 * MOS:GNL is not an essay. I'd also be wary of calling new gender-neutral terms neologisms, there's a clear reason for their use. In hindsight I shouldn't have changed all the mentions to "crewed" though. One pilot does not a crew make. The lede still suggests "crewed" is the proper term, so maybe @Steelpillow should look into changing that too? HansVonStuttgart (talk) 09:28, 28 August 2023 (UTC)
 * I have no problem with the lead as it is. The term "crew" is ambiguous; on the one hand we may talk of say a "Captain and crew", but on the other we may say that a plane has a "crew of three", meaning a pilot Captain and two additional persons. A tethered observation balloon, and a few other examples, may have a crew but no pilot. A few aircraft have carried passengers but no onboard crew at all (ancient Chinese punishment kites, for example), but these points are too minor for the lede. At some point we will have a rash of pilotless air taxis and the like appearing, and we will have to revisit the lede, but probably not for a while. — Cheers, Steelpillow (Talk) 13:14, 28 August 2023 (UTC)
 * @HansVonStuttgart: My apologies for confusing WP:GNL with MOS:GNL. (Something should be done to remove the confusion.) But I stand by my other point that many cases of GNL are neologistic, especially this one. To state this another way, "manned aircraft"/"unmanned aircraft" and "crewed aircraft"/"uncrewed aircraft" are not currently interchangeable in most cases, as Steelpillow's examples illustrate. That may change in the future, and the terms will evolve to fill in the nuances, but we aren't there yet, which is the point of MOS:NEO. However, "manned spacecraft" and "crewed spacecraft" are mostly interchangeable, and NASA has been using the latter instead of the former for a number of years. BilCat (talk) 01:10, 29 August 2023 (UTC)
 * We should note that while MOS:GNL is indeed not an essay (as WP:GNL is), it is not binding policy either; it sits within WP:MOS and as such is a guideline. Within this status in mind, it recommends us to "Use gender-neutral language – avoiding the generic he and generic she, for example – if this can be done with clarity and precision." Often, as here, it can not be. As for neologisms, the article on the neologism and WP:NEO both agree that a neologism may already have become widely accepted (and even notable enough for its own article), whereas MOS:NEO treats it as an unacceptable fringe term. Since the latter is only a guideline, while WP:MOS is policy, one must question this recommendation of the style guide. — Cheers, Steelpillow (Talk) 07:57, 29 August 2023 (UTC)

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title: Talk:Aircraft


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Antiparticle

In particle physics, every type of particle of "ordinary" matter (as opposed to antimatter) is associated with an antiparticle with the same mass but with opposite physical charges (such as electric charge). For example, the antiparticle of the electron is the positron (also known as an antielectron). While the electron has a negative electric charge, the positron has a positive electric charge, and is produced naturally in certain types of radioactive decay. The opposite is also true: the antiparticle of the positron is the electron.

Some particles, such as the photon, are their own antiparticle. Otherwise, for each pair of antiparticle partners, one is designated as the normal particle (the one that occurs in matter usually interacted with in daily life). The other (usually given the prefix "anti-") is designated the antiparticle.

Particle–antiparticle pairs can annihilate each other, producing photons; since the charges of the particle and antiparticle are opposite, total charge is conserved. For example, the positrons produced in natural radioactive decay quickly annihilate themselves with electrons, producing pairs of gamma rays, a process exploited in positron emission tomography.

The laws of nature are very nearly symmetrical with respect to particles and antiparticles. For example, an antiproton and a positron can form an antihydrogen atom, which is believed to have the same properties as a hydrogen atom. This leads to the question of why the formation of matter after the Big Bang resulted in a universe consisting almost entirely of matter, rather than being a half-and-half mixture of matter and antimatter. The discovery of charge parity violation helped to shed light on this problem by showing that this symmetry, originally thought to be perfect, was only approximate. The question about how the formation of matter after the Big Bang resulted in a universe consisting almost entirely of matter remains an unanswered one, and explanations so far are not truly satisfactory, overall.

Because charge is conserved, it is not possible to create an antiparticle without either destroying another particle of the same charge (as is for instance the case when antiparticles are produced naturally via beta decay or the collision of cosmic rays with Earth's atmosphere), or by the simultaneous creation of both a particle and its antiparticle (pair production), which can occur in particle accelerators such as the Large Hadron Collider at CERN.

Particles and their antiparticles have equal and opposite charges, so that an uncharged particle also gives rise to an uncharged antiparticle. In many cases, the antiparticle and the particle coincide: pairs of photons, Z0 bosons, Pi meson mesons, and hypothetical gravitons and some hypothetical WIMPs all self-annihilate. However, electrically neutral particles need not be identical to their antiparticles: for example, the neutron and antineutron are distinct.

Experiment
In 1932, soon after the prediction of positrons by Paul Dirac, Carl D. Anderson found that cosmic-ray collisions produced these particles in a cloud chamber – a particle detector in which moving electrons (or positrons) leave behind trails as they move through the gas. The electric charge-to-mass ratio of a particle can be measured by observing the radius of curling of its cloud-chamber track in a magnetic field. Positrons, because of the direction that their paths curled, were at first mistaken for electrons travelling in the opposite direction. Positron paths in a cloud-chamber trace the same helical path as an electron but rotate in the opposite direction with respect to the magnetic field direction due to their having the same magnitude of charge-to-mass ratio but with opposite charge and, therefore, opposite signed charge-to-mass ratios.

The antiproton and antineutron were found by Emilio Segrè and Owen Chamberlain in 1955 at the University of California, Berkeley. Since then, the antiparticles of many other subatomic particles have been created in particle accelerator experiments. In recent years, complete atoms of antimatter have been assembled out of antiprotons and positrons, collected in electromagnetic traps.

Dirac hole theory
Solutions of the Dirac equation contain negative energy quantum states. As a result, an electron could always radiate energy and fall into a negative energy state. Even worse, it could keep radiating infinite amounts of energy because there were infinitely many negative energy states available. To prevent this unphysical situation from happening, Dirac proposed that a "sea" of negative-energy electrons fills the universe, already occupying all of the lower-energy states so that, due to the Pauli exclusion principle, no other electron could fall into them. Sometimes, however, one of these negative-energy particles could be lifted out of this Dirac sea to become a positive-energy particle. But, when lifted out, it would leave behind a hole in the sea that would act exactly like a positive-energy electron with a reversed charge. These holes were interpreted as "negative-energy electrons" by Paul Dirac and mistakenly identified  with protons in his 1930 paper A Theory of Electrons and Protons However, these "negative-energy electrons" turned out to be positrons, and not protons.

This picture implied an infinite negative charge for the universe – a problem of which Dirac was aware. Dirac tried to argue that we would perceive this as the normal state of zero charge. Another difficulty was the difference in masses of the electron and the proton. Dirac tried to argue that this was due to the electromagnetic interactions with the sea, until Hermann Weyl proved that hole theory was completely symmetric between negative and positive charges. Dirac also predicted a reaction Electron + Proton+ → Photon + Photon, where an electron and a proton annihilate to give two photons. Robert Oppenheimer and Igor Tamm, however, proved that this would cause ordinary matter to disappear too fast. A year later, in 1931, Dirac modified his theory and postulated the positron, a new particle of the same mass as the electron. The discovery of this particle the next year removed the last two objections to his theory.

Within Dirac's theory, the problem of infinite charge of the universe remains. Some bosons also have antiparticles, but since bosons do not obey the Pauli exclusion principle (only fermions do), hole theory does not work for them. A unified interpretation of antiparticles is now available in quantum field theory, which solves both these problems by describing antimatter as negative energy states of the same underlying matter field, i.e. particles moving backwards in time.

Particle–antiparticle annihilation

If a particle and antiparticle are in the appropriate quantum states, then they can annihilate each other and produce other particles. Reactions such as Electron + Positron → PhotonPhoton (the two-photon annihilation of an electron-positron pair) are an example. The single-photon annihilation of an electron-positron pair, Electron + Positron → Photon, cannot occur in free space because it is impossible to conserve energy and momentum together in this process. However, in the Coulomb field of a nucleus the translational invariance is broken and single-photon annihilation may occur. The reverse reaction (in free space, without an atomic nucleus) is also impossible for this reason. In quantum field theory, this process is allowed only as an intermediate quantum state for times short enough that the violation of energy conservation can be accommodated by the uncertainty principle. This opens the way for virtual pair production or annihilation in which a one particle quantum state may fluctuate into a two particle state and back. These processes are important in the vacuum state and renormalization of a quantum field theory. It also opens the way for neutral particle mixing through processes such as the one pictured here, which is a complicated example of mass renormalization.

Properties
Quantum states of a particle and an antiparticle are interchanged by the combined application of charge conjugation $$ C $$, parity $$ P $$ and time reversal $$ T $$. $$ C $$ and $$ P $$ are linear, unitary operators, $$ T $$ is antilinear and antiunitary, $$ \langle \Psi | T\,\Phi\rangle = \langle \Phi | T^{-1}\,\Psi\rangle $$. If $$|p,\sigma ,n \rangle $$ denotes the quantum state of a particle $$ n $$ with momentum $$ p $$ and spin $$ J $$ whose component in the z-direction is $$ \sigma $$, then one has
 * $$CPT \ |p,\sigma,n \rangle\ =\ (-1)^{J-\sigma}\ |p,-\sigma,n^c \rangle ,$$

where $$ n^c $$ denotes the charge conjugate state, that is, the antiparticle. In particular a massive particle and its antiparticle transform under the same irreducible representation of the Poincaré group which means the antiparticle has the same mass and the same spin.

If $$C$$, $$P$$ and $$T$$ can be defined separately on the particles and antiparticles, then
 * $$T\ |p,\sigma,n\rangle \ \propto \ |-p,-\sigma,n\rangle ,$$
 * $$CP\ |p,\sigma,n\rangle \ \propto \ |-p,\sigma,n^c\rangle ,$$
 * $$C\ |p,\sigma,n\rangle \ \propto \ |p,\sigma,n^c\rangle ,$$

where the proportionality sign indicates that there might be a phase on the right hand side.

As $$ CPT $$ anticommutes with the charges, $$ CPT\,Q = - Q\, CPT $$, particle and antiparticle have opposite electric charges q and -q.

Quantum field theory

 * This section draws upon the ideas, language and notation of canonical quantization of a quantum field theory.

One may try to quantize an electron field without mixing the annihilation and creation operators by writing

 * $$\psi (x)=\sum_{k}u_k (x)a_k e^{-iE(k)t},\,$$

where we use the symbol k to denote the quantum numbers p and σ of the previous section and the sign of the energy, E(k), and ak denotes the corresponding annihilation operators. Of course, since we are dealing with fermions, we have to have the operators satisfy canonical anti-commutation relations. However, if one now writes down the Hamiltonian

 * $$H=\sum_{k} E(k) a^\dagger_k a_k,\,$$

then one sees immediately that the expectation value of H need not be positive. This is because E(k) can have any sign whatsoever, and the combination of creation and annihilation operators has expectation value 1 or 0.

So one has to introduce the charge conjugate antiparticle field, with its own creation and annihilation operators satisfying the relations

 * $$b_{k\prime} = a^\dagger_k\ \mathrm{and}\ b^\dagger_{k\prime}=a_k,\,$$

where k has the same p, and opposite σ and sign of the energy. Then one can rewrite the field in the form

 * $$\psi(x)=\sum_{k_+} u_k (x)a_k e^{-iE(k)t}+\sum_{k_-} u_k (x)b^\dagger _k e^{-iE(k)t},\,$$

where the first sum is over positive energy states and the second over those of negative energy. The energy becomes

 * $$H=\sum_{k_+} E_k a^\dagger _k a_k + \sum_{k_-} |E(k)|b^\dagger_k b_k + E_0,\,$$

where E0 is an infinite negative constant. The vacuum state is defined as the state with no particle or antiparticle, i.e., $$a_k |0\rangle=0$$ and $$b_k |0\rangle=0$$. Then the energy of the vacuum is exactly E0. Since all energies are measured relative to the vacuum, H is positive definite. Analysis of the properties of ak and bk shows that one is the annihilation operator for particles and the other for antiparticles. This is the case of a fermion.

This approach is due to Vladimir Fock, Wendell Furry and Robert Oppenheimer. If one quantizes a real scalar field, then one finds that there is only one kind of annihilation operator; therefore, real scalar fields describe neutral bosons. Since complex scalar fields admit two different kinds of annihilation operators, which are related by conjugation, such fields describe charged bosons.

Feynman–Stückelberg interpretation
By considering the propagation of the negative energy modes of the electron field backward in time, Ernst Stückelberg reached a pictorial understanding of the fact that the particle and antiparticle have equal mass m and spin J but opposite charges q. This allowed him to rewrite perturbation theory precisely in the form of diagrams. Richard Feynman later gave an independent systematic derivation of these diagrams from a particle formalism, and they are now called Feynman diagrams. Each line of a diagram represents a particle propagating either backward or forward in time. In Feynman diagrams, anti-particles are shown traveling backwards in time relative to normal matter, and vice versa. This technique is the most widespread method of computing amplitudes in quantum field theory today.

Since this picture was first developed by Stückelberg, and acquired its modern form in Feynman's work, it is called the Feynman–Stückelberg interpretation of antiparticles to honor both scientists.

title: Antiparticle


text:
Talk:Anno Domini/Archive 1

eventually I'll get around to writing about why Bede and Charlemagne's court were probably also using A.D. to suppress certain apocalyptic worries inherent in the system of using dating since the creation of the world - they were creeping up on the year 6000....  Oh - and don't even get me started on when 'a' year begins. For the A.U.C. Roman system it starts on April 21, the anniversary of foundation. Lately we've been starting years on January 1. --MichaelTinkler

What does A.U.C. mean exactly? -rmhermen

Make sure you cross-reference and avoid duplicating the stuff in Calendar. --LDC

- whoops! Ab Urbe Condita, "from the foundation of the City" - will insert. Feel free to cross reference all you see fit - but erae and calendars are technically different. - I know everyone says Anno Domini means "Year of Our Lord"; but literally speaking doesn't it just mean "Year of Lord"? The Latin phrase does not contain the word "our" anywhere in it. -- no, it's just 'year of the Lord', literally, but the idiomatic usage is Our. Oh, by the way, always feel free to add 'a' or 'the' when translating Latin. Latin doesn't have an article at all. --MichaelTinkler

title: Talk:Anno Domini/Archive 1


text:
Arabian Prince

Kim Renard Nazel (born June 17, 1965), better known by his stage names Arabian Prince or Professor X, is an American rapper, record producer, and DJ. He was a founding member of N.W.A. and performed on one track from the group's major debut Straight Outta Compton before leaving.

Early life
Nazel was born in Compton, California to the son of Joseph "Skippy" Nazel Jr., an African-American author and radio talk show host. His musical background came from his mother, a piano teacher and classical musician. His family tried its best to shelter him, sending him to a Catholic school and keeping him busy with football to keep him away from the gangs. The younger Nazel got his first experience with making music at the radio station his father hosted his talk show on; Nazel used the radio station's equipment to put together mixtapes that he would sell at school. Nazel went on to graduate from Junípero Serra High School in nearby Gardena.

Music career
Nazel took the stage name of DJ Prince and started selling mixtapes at school. While working at a luggage store at the Del Amo Mall, its owner, Sam Nassif, asked him to DJ a party at a community center. He kept performing there for several weekends and the success persuaded Nassif to invest even more in the place, renaming it "The Cave", where Nazel would continue to host for over three years and even after his N.W.A days. Nassif also funded DJ Prince's first record, "Strange Life".

He changed his stage name when he was 15 years old at the Skateland USA, the same skating venue credited for launching N.W.A a few years later, due to a fan's suggestion. He said about his name: "I called myself DJ Prince at first; back in the day, I always used to dress like Prince. That was the thing in the early '80s — either you dressed like Prince or you dressed like Michael Jackson. I used to wear the tight parachute pants, and I had the trim moustache, the whole thing. One day I was DJing at a skating rink. I was with Egyptian Lover, that was my boy, still is. This girl comes up to us and asks us our names. And he's like, 'I'm Egyptian Lover.' And I'm like, 'I'm DJ Prince.' She looks at me and goes, 'I always see you two together. You should call yourself Arabian Prince.' And I guess that just stuck."

Arabian Prince started working with Bobby Jimmy & the Critters in 1984. He also produced the hit single and album for J.J. Fad, "Supersonic".

In 1986, he was a founding member of N.W.A, helping with production on some tracks and appearing as a vocalist on the last track of N.W.A.'s hit studio album Straight Outta Compton (1988), "Something 2 Dance 2", a relatively radio-friendly song which was also removed from later pressings of the album due to a dispute. Arabian Prince left over royalty and contract disagreements. "I started off as a solo artist", he said, "so I was aware of what a royalty statement was. I knew that when these many records were sold, there is a quarterly statement. When you look at it, you can see how much money was paid and then share it. This was not the case. We were also never paid for touring." Eazy-E, Ice Cube and MC Ren remained as the main performers, DJ Yella was the turntablist and Dr. Dre was the main producer.

After leaving N.W.A, Arabian Prince began a solo career. His first album, Brother Arab, was released in 1989 with the single "She's Got A Big Posse"; Where's My Bytches followed in 1993.

In the mid-2000s, he started releasing music again, with his Professor X project on the Dutch label Clone Records. "I could not release the record under Arabian Prince", he said, "because I already had a single out, so I called myself Professor X on that record." In 2007, he performed as a DJ on the 2K Sports Holiday Bounce Tour with artists from the Stones Throw label. In 2008, Stones Throw released a compilation of his electro-rap material from the 1980s. One of his songs was included on the 2007 video game, College Hoops 2K8.

In 2015, a biopic about N.W.A. titled Straight Outta Compton was released; however, Arabian Prince was not portrayed in the film. After the release film, Prince said to VladTV: "A lot of the scenes in real life, I was there—I'm just not there in the film, which I'm like, if you're gonna write me out of a movie, shoot some other scenes. Don't write scenes where I was there." Some of the pivotal scenes would be choosing the name for the band, the tour and the infamous Detroit concert. He also remembers himself as the main opposer to Jerry Heller about the royalties and the money, a role that in the film was instead given to Ice Cube.

The following year, N.W.A. was inducted into the Rock and Roll Hall of Fame, but again, Arabian Prince was not included nor mentioned.

In 2018, Arabian Prince appeared on the AmeriKKKant album of industrial-metal band Ministry. He made a second appearance on Ministry's 2021 album Moral Hygiene.

Other ventures
Aside from his music career, he worked in special effects, 3D animation and video games.

Solo

 * Strange Life (Rapsur, 1984)
 * It Ain’t Tough (Rapsur, 1985)
 * Take You Home Girl / Innovator (Rapsur, 1985)
 * Situation Hot (Street Kut, 1986)
 * Freak City (Macola, 1986)
 * Professor X (Saga) (Techno Kut, 1989)
 * Brother Arab (Orpheus, 1989)
 * Where's My Bytches (Da Bozak, 1993)
 * Simple Planet / Beatdabeat (Stones Throw, 2008)

Compilations

 * Situation Hot (Macola, 1990)
 * Innovative Life: The Anthology, 1984–1989 (Stones Throw, 2008)
 * Professor X (Clone, 2007/2008)

With Bobby Jimmy and the Critters

 * Ugly Knuckle Butt (1985)
 * Roaches: The Beginning (1986)
 * Back and Proud (1987)

With N.W.A

 * "Panic Zone" (single) (1987)
 * N.W.A. and the Posse (1987)
 * Straight Outta Compton (1988)

title: Arabian Prince


text:
August 7

Pre-1600

 * 461 – Roman Emperor Majorian is beheaded near the river Iria in north-west Italy following his arrest and deposition by the magister militum Ricimer.
 * 626 – The Avar and Slav armies leave the siege of Constantinople.
 * 768 – Pope Stephen III is elected to office, and quickly seeks Frankish protection against the Lombard threat, since the Byzantine Empire is no longer able to help.
 * 936 – Coronation of King Otto I of Germany.
 * 1461 – The Ming dynasty Chinese military general Cao Qin stages a coup against the Tianshun Emperor.
 * 1479 – Battle of Guinegate: French troops of King Louis XI were defeated by the Burgundians led by Archduke Maximilian of Habsburg.

1601–1900

 * 1679 – The brigantine Le Griffon becomes the first ship to sail the upper Great Lakes of North America.
 * 1714 – The Battle of Gangut: The first important victory of the Russian Navy.
 * 1743 – The Treaty of Åbo ended the 1741–1743 Russo-Swedish War.
 * 1782 – George Washington orders the creation of the Badge of Military Merit to honor soldiers wounded in battle. It is later renamed to the more poetic Purple Heart.
 * 1786 – The first federal Indian Reservation is created by the United States.
 * 1789 – The United States Department of War is established.
 * 1791 – American troops destroy the Miami town of Kenapacomaqua near the site of present-day Logansport, Indiana in the Northwest Indian War.
 * 1794 – U.S. President George Washington invokes the Militia Acts of 1792 to suppress the Whiskey Rebellion in western Pennsylvania.
 * 1819 – Simón Bolívar triumphs over Spain in the Battle of Boyacá.
 * 1858 – The first Australian rules football match is played between Melbourne Grammar and Scotch College.
 * 1890 – Anna Månsdotter, found guilty of the 1889 Yngsjö murder, became the last woman to be executed in Sweden.

1901–present

 * 1909 – Alice Huyler Ramsey and three friends become the first women to complete a transcontinental auto trip, taking 59 days to travel from New York, New York to San Francisco, California.
 * 1927 – The Peace Bridge opens between Fort Erie, Ontario and Buffalo, New York.
 * 1930 – The last confirmed lynching of black people in the Northern United States occurs in Marion, Indiana; two men, Thomas Shipp and Abram Smith, are killed.
 * 1933 – The Kingdom of Iraq slaughters over 3,000 Assyrians in the village of Simele. This date is recognized as Martyrs Day or National Day of Mourning by the Assyrian community in memory of the Simele massacre.
 * 1942 – World War II: The Battle of Guadalcanal begins as the United States Marines initiate the first American offensive of the war with landings on Guadalcanal and Tulagi in the Solomon Islands.
 * 1944 – IBM dedicates the first program-controlled calculator, the Automatic Sequence Controlled Calculator (known best as the Harvard Mark I).
 * 1946 – The government of the Soviet Union presented a note to its Turkish counterparts which refuted the latter's sovereignty over the Turkish Straits, thus beginning the Turkish Straits crisis.
 * 1947 – Thor Heyerdahl's balsa wood raft, the Kon-Tiki, smashes into the reef at Raroia in the Tuamotu Islands after a 101-day, 7000 km journey across the Pacific Ocean in an attempt to prove that pre-historic peoples could have traveled from South America.
 * 1947  – The Bombay Municipal Corporation formally takes over the Bombay Electric Supply and Transport (BEST).
 * 1959 – Explorer program: Explorer 6 launches from the Atlantic Missile Range in Cape Canaveral, Florida.
 * 1960 – Ivory Coast becomes independent from France.
 * 1962 – Canadian-born American pharmacologist Frances Oldham Kelsey is awarded the U.S. President's Award for Distinguished Federal Civilian Service for her refusal to authorize thalidomide.
 * 1964 – Vietnam War: The U.S. Congress passes the Gulf of Tonkin Resolution giving U.S. President Lyndon B. Johnson broad war powers to deal with North Vietnamese attacks on American forces.
 * 1969 – Richard Nixon appoints Luis R. Bruce, a Mohawk-Oglala Sioux and co-founder of the National Congress of American Indians, as the new commissioner of the Bureau of Indian Affairs.
 * 1970 – California judge Harold Haley is taken hostage in his courtroom and killed during an effort to free George Jackson from police custody.
 * 1974 – Philippe Petit performs a high wire act between the twin towers of the World Trade Center 1368 ft in the air.
 * 1976 – Viking program: Viking 2 enters orbit around Mars.
 * 1978 – U.S. President Jimmy Carter declares a federal emergency at Love Canal due to toxic waste that had been disposed of negligently.
 * 1981 – The Washington Star ceases all operations after 128 years of publication.
 * 1985 – Takao Doi, Mamoru Mohri and Chiaki Mukai are chosen to be Japan's first astronauts.
 * 1987 – Cold War: Lynne Cox becomes the first person to swim from the United States to the Soviet Union, crossing the Bering Strait from Little Diomede Island in Alaska to Big Diomede in the Soviet Union.
 * 1989 – U.S. Congressman Mickey Leland (D-TX) and 15 others die in a plane crash in Ethiopia.
 * 1990 – First American soldiers arrive in Saudi Arabia as part of the Gulf War.
 * 1993 – Ada Deer, a Menominee activist, is sworn in as the head of the Bureau of Indian Affairs.
 * 1995 – The Chilean government declares state of emergency in the southern half of the country in response to an event of intense, cold, wind, rain and snowfall known as the White Earthquake.
 * 1997 – Space Shuttle Program: The Space Shuttle Discovery launches on STS-85 from the Kennedy Space Center in Cape Canaveral, Florida.
 * 1997  – Fine Air Flight 101 crashes after takeoff from Miami International Airport, killing five people.
 * 1998 – Bombings at United States embassies in Dar es Salaam, Tanzania and Nairobi, Kenya kill approximately 212 people.
 * 1999 – The Chechnya-based Islamic International Brigade invades neighboring Dagestan.
 * 2007 – At AT&T Park, Barry Bonds hits his 756th career home run to surpass Hank Aaron's 33-year-old record.
 * 2008 – The start of the Russo-Georgian War over the territory of South Ossetia.
 * 2020 – Air India Express Flight 1344 overshoots the runway at Calicut International Airport in the Malappuram district of Kerala, India, and crashes, killing 21 of the 190 people on board.

Pre-1600

 * 317 – Constantius II, Roman emperor (d. 361)
 * 1282 – Elizabeth of Rhuddlan (d. 1316)
 * 1533 – Alonso de Ercilla, Spanish soldier and poet (d. 1595)
 * 1560 – Elizabeth Báthory, Hungarian aristocrat and purported serial killer (d. 1614)
 * 1571 – Thomas Lupo, English viol player and composer (d. 1627)
 * 1574 – Robert Dudley, English explorer and cartographer (d. 1649)
 * 1598 – Georg Stiernhielm, Swedish poet and linguist (d. 1672)

1601–1900

 * 1613 – William Frederick, Prince of Nassau-Dietz, Dutch stadtholder (d. 1664)
 * 1702 – Muhammad Shah, Mughal emperor of India (d. 1748)
 * 1726 – James Bowdoin, American banker and politician, 2nd Governor of Massachusetts (d. 1790)
 * 1742 – Nathanael Greene, American general (d. 1786)
 * 1751 – Wilhelmina of Prussia, Princess of Orange (d. 1820)
 * 1779  – Carl Ritter, German geographer and academic (d. 1859)
 * 1826 – August Ahlqvist, Finnish professor, poet, scholar of the Finno-Ugric languages, author, and literary critic (d. 1889)
 * 1844 – Auguste Michel-Lévy, French geologist and author (d. 1911)
 * 1860 – Alan Leo, English astrologer and author (d. 1917)
 * 1862 – Henri Le Sidaner, French painter (d. 1939)
 * 1862  – Victoria of Baden (d. 1931)
 * 1867 – Emil Nolde, Danish-German painter and illustrator (d. 1956)
 * 1868 – Ladislaus Bortkiewicz, Russian-German economist and statistician (d. 1931)
 * 1868  – Huntley Wright, English actor (d. 1941)
 * 1869 – Mary Frances Winston, American mathematician (d. 1959)
 * 1876 – Mata Hari, Dutch dancer and spy (d. 1917)
 * 1879 – Johannes Kotze, South African cricketer (d. 1931)
 * 1884 – Billie Burke, American actress and singer (d. 1970)
 * 1884  – Nikolai Triik, Estonian painter and illustrator (d. 1940)
 * 1887 – Anna Elisabet Weirauch, German author and playwright (d. 1970)
 * 1890 – Elizabeth Gurley Flynn, American author and activist (d. 1964)

1901–present

 * 1901 – Ann Harding, American actress and singer (d. 1981)
 * 1903 – Louis Leakey, Kenyan-English palaeontologist and archaeologist (d. 1972)
 * 1904 – Ralph Bunche, American political scientist, academic, and diplomat, Nobel Prize laureate (d. 1971)
 * 1907 – Albert Kotin, Belarusian-American soldier and painter (d. 1980)
 * 1910 – Freddie Slack, American pianist and bandleader (d. 1965)
 * 1911 – István Bibó, Hungarian lawyer and politician (d. 1979)
 * 1911  – Nicholas Ray, American director and screenwriter (d. 1979)
 * 1913 – George Van Eps, American guitarist (d. 1998)
 * 1916 – Kermit Love, American actor, puppeteer, and costume designer (d. 2008)
 * 1918 – C. Buddingh', Dutch poet and translator (d. 1985)
 * 1918  – Gordon Zahn, American sociologist and author (d. 2007)
 * 1921 – Manitas de Plata, French guitarist (d. 2014)
 * 1921  – Karel Husa, Czech-American composer and conductor (d. 2016)
 * 1924 – Kenneth Kendall, Indian-English journalist and actor (d. 2012)
 * 1925 – Felice Bryant, American songwriter (d. 2003)
 * 1926 – Stan Freberg, American puppeteer, voice actor, and singer (d. 2015)
 * 1927 – Rocky Bridges, American baseball player and coach (d. 2015)
 * 1927  – Edwin Edwards, American soldier, lawyer, and politician, 50th Governor of Louisiana (d. 2021)
 * 1927  – Art Houtteman, American baseball player and journalist (d. 2003)
 * 1928 – Betsy Byars, American author and academic (d. 2020)
 * 1928  – Owen Luder, English architect, designed Tricorn Centre and Trinity Square (d. 2021)
 * 1928  – James Randi, Canadian-American stage magician and author (d. 2020)
 * 1929 – Don Larsen, American baseball player (d. 2020)
 * 1930 – Togrul Narimanbekov, Azerbaijani-French painter and academic (d. 2013)
 * 1930  – Veljo Tormis, Estonian composer and educator (d. 2017)
 * 1931 – Jack Good, British television producer (d. 2017)
 * 1931  – Charles E. Rice, American scholar and author (d. 2015)
 * 1932 – Abebe Bikila, Ethiopian runner (d. 1973)
 * 1932  – Edward Hardwicke, English actor (d. 2011)
 * 1932  – Rien Poortvliet, Dutch painter and illustrator (d. 1995)
 * 1932  – Maurice Rabb, Jr., American ophthalmologist and academic (d. 2005)
 * 1933 – Eddie Firmani, South African footballer and manager
 * 1933  – Elinor Ostrom, American economist and academic, Nobel Prize laureate (d. 2012)
 * 1933  – Jerry Pournelle, American journalist and author (d. 2017)
 * 1933  – Alberto Romulo, Filipino politician and diplomat
 * 1934 – Sándor Simó, Hungarian director, producer, and screenwriter (d. 2001)
 * 1935 – Lee Corso, American college football coach and broadcaster
 * 1935  – Rahsaan Roland Kirk, American saxophonist and composer (d. 1977)
 * 1937 – Zoltán Berczik, Hungarian table tennis player and coach (d. 2011)
 * 1937  – Don Wilson, English cricketer and coach (d. 2012)
 * 1938 – Giorgetto Giugiaro, Italian automotive designer
 * 1940 – Jean-Luc Dehaene, French-Belgian lawyer and politician, 63rd Prime Minister of Belgium (d. 2014)
 * 1940  – Uwe Nettelbeck, German record producer, journalist and film critic (d. 2007)
 * 1941 – Matthew Evans, Baron Evans of Temple Guiting, English publisher and politician (d. 2016)
 * 1942 – Garrison Keillor, American humorist, novelist, short story writer, and radio host
 * 1942  – Carlos Monzón, Argentinian boxer and actor (d. 1995)
 * 1942  – Caetano Veloso, Brazilian singer-songwriter, writer and producer
 * 1942  – Richard Sykes, English biochemist and academic
 * 1942  – B. J. Thomas, American singer (d. 2021)
 * 1943 – Mohammed Badie, Egyptian religious leader
 * 1943  – Lana Cantrell, Australian singer-songwriter and lawyer
 * 1943  – Alain Corneau, French director and screenwriter (d. 2010)
 * 1944 – John Glover, American actor
 * 1944  – Robert Mueller, American soldier and lawyer, 6th Director of the Federal Bureau of Investigation
 * 1945 – Kenny Ireland, Scottish actor and director (d. 2014)
 * 1945  – Alan Page, American football player and jurist
 * 1947 – Franciscus Henri, Dutch-Australian singer-songwriter
 * 1947  – Sofia Rotaru, Ukrainian singer-songwriter, producer, and actress
 * 1948 – Marty Appel, American businessman and author
 * 1948  – Greg Chappell, Australian cricketer and coach
 * 1949 – Walid Jumblatt, Lebanese journalist and politician
 * 1949  – Matthew Parris, South African-English journalist and politician
 * 1950 – Rodney Crowell, American singer-songwriter and guitarist
 * 1950  – Alan Keyes, American politician and diplomat, 16th Assistant Secretary of State for International Organization Affairs
 * 1950  – S. Thandayuthapani, Sri Lankan educator and politician
 * 1952 – Caroline Aaron, American actress and producer
 * 1952  – Eamonn Darcy, Irish golfer
 * 1952  – Kees Kist, Dutch footballer
 * 1952  – Alexei Sayle, English comedian, actor, and author
 * 1953 – Anne Fadiman, American journalist and author
 * 1954 – Valery Gazzaev, Russian footballer, manager and politician
 * 1954  – Jonathan Pollard, Israeli spy
 * 1954  – Alan Reid, Scottish politician
 * 1955 – Wayne Knight, American actor, comedian and voice actor
 * 1955  – Greg Nickels, American lawyer and politician, 51st Mayor of Seattle
 * 1955  – Vladimir Sorokin, Russian author and playwright
 * 1957 – Daire Brehan, Irish journalist, lawyer, and actress (d. 2012)
 * 1957  – Alexander Dityatin, Russian gymnast and colonel
 * 1958 – Russell Baze, Canadian-American jockey
 * 1958  – Bruce Dickinson, English singer-songwriter and guitarist
 * 1958  – Alberto Salazar, Cuban-American runner and coach
 * 1959 – Koenraad Elst, Belgian orientalist and author
 * 1959  – Ali Shah, Zimbabwean cricketer and coach
 * 1960 – David Duchovny, American actor, director, producer, and screenwriter
 * 1961 – Brian Conley, English actor and singer
 * 1961  – Yelena Davydova, Russian gymnast
 * 1961  – Walter Swinburn, English jockey and trainer (d. 2016)
 * 1961  – Carlos Vives, Colombian singer, songwriter, and actor
 * 1962 – Alison Brown, American banjo player, songwriter, and producer
 * 1963 – Paul Dunn, Australian rugby league player
 * 1963  – Nick Gillespie, American journalist and author
 * 1963  – Marcus Roberts, American pianist and educator
 * 1964 – John Birmingham, English-Australian journalist and author
 * 1964  – Ian Dench, English guitarist and songwriter
 * 1964  – Peter Niven, Scottish jockey
 * 1965 – Raul Malo, American singer-songwriter, guitarist, and producer
 * 1965  – Elizabeth Manley, Canadian figure skater
 * 1966 – David Cairns, Scottish laicised priest and politician, Minister of State for Scotland (d. 2011)
 * 1966  – Shobna Gulati, British actress
 * 1966  – Kristin Hersh, American singer-songwriter and guitarist
 * 1966  – Jimmy Wales, American-British entrepreneur, co-founder of Wikipedia
 * 1967 – Jason Grimsley, American baseball player
 * 1968 – Francesca Gregorini, Italian-American director and screenwriter
 * 1968  – Trevor Hendy, Australian surfer and coach
 * 1968  – Sophie Lee, Australian actress and author
 * 1969 – Markus Bundi, Swiss writer
 * 1969  – Paul Lambert, Scottish footballer and manager
 * 1969  – Dana G. Peleg, Israeli writer and LGBT activist
 * 1970 – Eric Namesnik, American swimmer (d. 2006)
 * 1971 – Dominic Cork, England cricketer and sportscaster
 * 1971  – Rachel York, American actress and singer
 * 1972 – Gerry Peñalosa, Filipino boxer and promoter
 * 1973 – Mikhail Gorsheniov, Russian singer-songwriter (d. 2013)
 * 1973  – Danny Graves, Vietnamese-American baseball player
 * 1973  – Kevin Muscat, English-Australian footballer, coach, and manager
 * 1974 – Chico Benymon, American actor
 * 1974  – Michael Shannon, American actor
 * 1975 – Koray Candemir, Turkish singer-songwriter
 * 1975  – Gerard Denton, Australian cricketer
 * 1975  – Megan Gale, Australian model and actress
 * 1975  – Ray Hill, American football player (d. 2015)
 * 1975  – Rebecca Kleefisch, American journalist and politician, 44th Lieutenant Governor of Wisconsin
 * 1975  – Édgar Rentería, Colombian baseball player
 * 1975  – Charlize Theron, South African actress
 * 1976 – Dimitrios Eleftheropoulos, Greek footballer and manager
 * 1976  – Shane Lechler, American football player
 * 1977 – Charlotte Ronson, English fashion designer
 * 1977  – Samantha Ronson, English singer-songwriter and DJ
 * 1977  – Justin Brooker, Rugby League Player
 * 1978 – Alexandre Aja, French director, producer, and screenwriter
 * 1978  – Jamey Jasta, American singer-songwriter
 * 1978  – Mark McCammon, English-Barbadian footballer
 * 1978  – Cirroc Lofton, American actor
 * 1979 – Eric Johnson, American actor, director, and screenwriter
 * 1979  – Miguel Llera, Spanish footballer
 * 1979  – Birgit Zotz, Austrian anthropologist and author
 * 1980 – Carsten Busch, German footballer
 * 1980  – Aurélie Claudel, French model and actress
 * 1980  – Tácio Caetano Cruz Queiroz, Brazilian footballer
 * 1980  – Seiichiro Maki, Japanese footballer
 * 1981 – David Testo, American soccer player
 * 1981  – Randy Wayne, American actor and producer
 * 1982 – Ángeles Balbiani, Argentine actress and singer
 * 1982  – Abbie Cornish, Australian actress
 * 1982  – Juan Martín Hernández, Argentine rugby player
 * 1982  – Marquise Hill, American football player (d. 2007)
 * 1982  – Vassilis Spanoulis, Greek basketball player
 * 1982  – Martin Vučić, Macedonian singer and drummer
 * 1983 – Christian Chávez, Mexican singer-songwriter and actor
 * 1983  – Murat Dalkılıç, Turkish singer-songwriter
 * 1983  – Danny, Portuguese footballer
 * 1983  – Andriy Hrivko, Ukrainian cyclist
 * 1983  – Mark Pettini, English cricketer and journalist
 * 1984 – Stratos Perperoglou, Greek basketball player
 * 1984  – Tooba Siddiqui, Pakistani model and actress
 * 1984  – Yun Hyon-seok, South Korean poet and author (d. 2003)
 * 1986 – Paul Biedermann, German swimmer
 * 1986  – Valter Birsa, Slovenian footballer
 * 1986  – Altaír Jarabo, Mexican model and actress
 * 1986  – Juan de la Rosa, Mexican boxer
 * 1987 – Sidney Crosby, Canadian ice hockey player
 * 1987  – Mustapha Dumbuya, Sierra Leonean footballer
 * 1987  – Ryan Lavarnway, American baseball player
 * 1987  – Rouven Sattelmaier, German footballer
 * 1988 – Jonathan Bernier, Canadian ice hockey player
 * 1988  – Mohamed Coulibaly, Senegalese footballer
 * 1988  – Anisa Mohammed, West Indian cricketer
 * 1988  – Melody Oliveria, American blogger
 * 1988  – Erik Pieters, Dutch footballer
 * 1988  – Beanie Wells, American football player
 * 1989 – DeMar DeRozan, American basketball player
 * 1990 – Jake Allen, Canadian ice hockey player
 * 1990  – Josh Franceschi, English singer-songwriter
 * 1991 – Luis Salom, Spanish motorcycle racer (d. 2016)
 * 1991  – Mitchell te Vrede, Dutch footballer
 * 1991  – Mike Trout, American baseball player
 * 1992 – Adam Yates, English cyclist
 * 1992  – Simon Yates, English cyclist
 * 1992  – E. J. Tackett, American bowler
 * 1992  – Wout Weghorst, Dutch footballer
 * 1993 – Francesca Eastwood, American actress and television personality
 * 1993  – Martti Nõmme, Estonian ski jumper
 * 1993  – Karol Zalewski, Polish sprinter
 * 1997 – Matty Cash, Polish footballer
 * 1997  – Kyler Murray, American football player
 * 1998 – Vladimir Barbu, Italian diver
 * 1998  – María Bazo, Peruvian windsurfer
 * 1998  – Jalen Hurts, American football player

Pre-1600

 * 461 – Majorian, Roman emperor (b. 420)
 * 707 – Li Chongjun, Chinese prince
 * 1028 – Alfonso V, king of León (b. 994)
 * 1106 – Henry IV, Holy Roman Emperor (b. 1050)
 * 1234 – Hugh Foliot, bishop of Hereford (b. c. 1155)
 * 1272 – Richard Middleton, English Lord Chancellor
 * 1296 – Heinrich II von Rotteneck, prince-bishop of Regensburg
 * 1385 – Joan of Kent, mother of Richard II (b. 1328)
 * 1485 – Alexander Stewart, duke of Albany (b. 1454)
 * 1547 – Cajetan, Italian priest and saint (b. 1480)

1601–1900

 * 1613 – Thomas Fleming, English judge and politician, Lord Chief Justice of England (b. 1544)
 * 1616 – Vincenzo Scamozzi, Italian architect, designed Teatro Olimpico (b. 1548)
 * 1632 – Robert de Vere, 19th Earl of Oxford, English soldier (b. 1575)
 * 1635 – Friedrich Spee, German poet and academic (b. 1591)
 * 1639 – Martin van den Hove, Dutch astronomer and mathematician (b. 1605)
 * 1661 – Jin Shengtan, Chinese journalist and critic (b. 1608)
 * 1787 – Francis Blackburne, English Anglican churchman and activist (b. 1705)
 * 1817 – Pierre Samuel du Pont de Nemours, French economist and politician (b. 1739)
 * 1834 – Joseph Marie Jacquard, French weaver and inventor, invented the Jacquard loom (b. 1752)
 * 1848 – Jöns Jacob Berzelius, Swedish chemist and academic (b. 1779)
 * 1855 – Mariano Arista, Mexican general and politician, 19th President of Mexico (b. 1802)
 * 1864 – Li Xiucheng, Chinese field marshal (b. 1823)
 * 1893 – Alfredo Catalani, Italian composer and academic (b. 1854)
 * 1899 – Jacob Maris, Dutch painter and educator (b. 1837)
 * 1900 – Wilhelm Liebknecht, German lawyer and politician (b. 1826)

1901–present

 * 1912 – François-Alphonse Forel, Swiss limnologist and academic (b. 1841)
 * 1917 – Edwin Harris Dunning, South African-English commander and pilot (b. 1891)
 * 1938 – Konstantin Stanislavski, Russian actor and director (b. 1863)
 * 1941 – Rabindranath Tagore, Indian author, poet, and playwright, Nobel Prize laureate (b. 1861)
 * 1948 – Charles Bryant, English-American actor and director (b. 1879)
 * 1953 – Abner Powell, American baseball player and manager (b. 1860)
 * 1957 – Oliver Hardy, American actor, singer, and director (b. 1892)
 * 1958 – Elizabeth Foreman Lewis, American author and educator (b. 1892)
 * 1960 – Luis Ángel Firpo, Argentine boxer (b. 1894)
 * 1963 – Ramon Vila Capdevila, last of the Spanish Maquis, holding out after the end of the Spanish Civil War (b. 1908)
 * 1968 – Giovanni Bracco, Italian race car driver (b. 1908)
 * 1969 – Jean Bastien, French professional footballer (b. 1915)
 * 1969  – Joseph Kosma, Hungarian-French composer (b. 1905)
 * 1970 – Harold Haley, American lawyer and judge (b. 1904)
 * 1970  – Jonathan P. Jackson, American bodyguard and kidnapper (b. 1953)
 * 1972 – Joi Lansing, American model, actress, and singer (b. 1929)
 * 1973 – Jack Gregory, Australian cricketer (b. 1895)
 * 1974 – Rosario Castellanos, Mexican poet and author (b. 1925)
 * 1974  – Sylvio Mantha, Canadian ice hockey player and coach (b. 1902)
 * 1978 – Eddie Calvert, English trumpeter (b. 1922)
 * 1981 – Gunnar Uusi, Estonian chess player (b. 1931)
 * 1985 – Grayson Hall, American actress (b. 1922)
 * 1987 – Camille Chamoun, Lebanese lawyer and politician, 7th President of Lebanon (b. 1900)
 * 1989 – Mickey Leland, American lawyer and politician (b. 1944)
 * 1994 – Larry Martyn, English actor (b. 1934)
 * 1995 – Brigid Brophy, English author and critic (b. 1929)
 * 2001 – Algirdas Lauritėnas, Lithuanian basketball player (b. 1932)
 * 2003 – K. D. Arulpragasam, Sri Lankan zoologist and academic (b. 1931)
 * 2003  – Mickey McDermott, American baseball player and coach (b. 1929)
 * 2004 – Red Adair, American firefighter (b. 1915)
 * 2004  – Colin Bibby, English ornithologist and academic (b. 1948)
 * 2005 – Peter Jennings, Canadian-American journalist and author (b. 1938)
 * 2005 – Ester Šimerová-Martinčeková, Slovak painter (b. 1909)
 * 2006 – Mary Anderson Bain, American lawyer and politician (b. 1911)
 * 2007 – Ernesto Alonso, Mexican actor, director, and producer (b. 1917)
 * 2007  – Angus Tait, New Zealand businessman, founded Tait Communications (b. 1919)
 * 2008 – Bernie Brillstein, American talent agent and producer (b. 1931)
 * 2008  – Andrea Pininfarina, Italian engineer and businessman (b. 1957)
 * 2009 – Louis E. Saavedra, American educator and politician, 48th Mayor of Albuquerque (b. 1933)
 * 2009  – Mike Seeger, American singer-songwriter (b. 1933)
 * 2010 – John Nelder, English mathematician and statistician (b. 1924)
 * 2011 – Mark Hatfield, American soldier, academic, and politician, 29th Governor of Oregon (b. 1922)
 * 2011  – Nancy Wake, New Zealand-English captain and spy (b. 1912)
 * 2012 – Murtuz Alasgarov, Azerbaijani academic and politician, Speaker of the National Assembly of Azerbaijan (b. 1928)
 * 2012  – Judith Crist, American critic and academic (b. 1922)
 * 2012  – Vladimir Kobzev, Russian footballer and coach (b. 1959)
 * 2012  – Anna Piaggi, Italian journalist and author (b. 1931)
 * 2012  – Mayer Zald, American sociologist and academic (b. 1931)
 * 2012  – Dušan Zbavitel, Czech indologist and author (b. 1925)
 * 2013 – Samuel G. Armistead, American linguist, historian, and academic (b. 1927)
 * 2013  – Almir Kayumov, Russian footballer (b. 1964)
 * 2013  – Anthony Pawson, English-Canadian biologist, chemist, and academic (b. 1952)
 * 2013  – Margaret Pellegrini, American actress and dancer (b. 1923)
 * 2013  – Meeli Truu, Estonian architect (b. 1946)
 * 2013  – Alexander Yagubkin, Russian boxer (b. 1961)
 * 2014 – Víctor Fayad, Argentine lawyer and politician (b. 1955)
 * 2014  – Perry Moss, American football player and coach (b. 1926)
 * 2014  – Henry Stone, American record producer (b. 1921)
 * 2015 – Manuel Contreras, Chilean general (b. 1929)
 * 2015  – Frances Oldham Kelsey, Canadian pharmacologist and physician (b. 1914)
 * 2015  – Louise Suggs, American golfer, co-founded LPGA (b. 1923)
 * 2016 – Bryan Clauson, American racing driver (b. 1989)
 * 2017 – Don Baylor, American baseball player (b. 1949)
 * 2017  – David Maslanka, American composer (b. 1943)
 * 2018 – M. Karunanidhi, Indian politician, former Tamil Nadu Chief Minister and prominent leader of Tamils (b. 1924)
 * 2018  – Stan Mikita, Slovak hockey player (b. 1940)
 * 2019 – David Berman, American musician, singer, poet and cartoonist (b. 1967)
 * 2020 – Lê Khả Phiêu, Vietnamese politician (b. 1931)
 * 2021 – Markie Post, American actress (b. 1950)
 * 2021  – Trevor Moore, American comedian (b. 1980)
 * 2022 – David McCullough, American historian and author (b. 1933)
 * 2023 – William Friedkin, American film director (b. 1935)

Holidays and observances

 * Assyrian Martyrs Day (Assyrian community)
 * Battle of Boyacá Day (Colombia)
 * Christian feast day:
 * Albert of Trapani
 * Cajetan of Thienna
 * Carpophorus and companions
 * Dometius of Persia
 * Donatus of Arezzo
 * Donatus of Besançon
 * Donatus of Muenstereifel
 * John Mason Neale and Catherine Winkworth (Episcopal Church (USA))
 * Nantovinus
 * Pope Sixtus II
 * August 7 (Eastern Orthodox liturgics)
 * Filseta (Ethiopian and Eritrean Orthodox Tewahedo Church)
 * Emancipation Day (Saint Kitts and Nevis)
 * Republic Day (Ivory Coast)
 * Youth Day (Kiribati)
 * National Purple Heart Day (United States)

title: August 7