All articles starting with P
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Piazza d'Oro at Hadrian's Villa
Piazza d'Oro (Golden Square) is a second-phase (125–133 AD) garden-court complex at Hadrian's Villa, Tivoli, with an octagonal pumpkin-domed vestibule, cipollino and granite colonnades, and 1987–88 excavations revealing Roman planting pits and irrigation.
Piazza del Campo
Piazza del Campo, also called Il Campo, is Siena's shell-shaped main square, formed at the meeting of three streets on three hills; 333 m circumference, nine segments honoring the Government of the Nine, site of the Palio since 1644 and part of the UNESCO-listed historic centre (1995).
Piazza del Duomo, Pisa
Piazza del Duomo, Pisa (Piazza dei Miracoli, Campo dei Miracoli): UNESCO World Heritage square (1987) with the Cathedral begun 1063 by Buscheto, Baptistery, Leaning Tower, and Camposanto; 8.87 ha, criteria i, ii, iv, vi.
Piazza del Popolo
Piazza del Popolo, Rome's monumental northern gateway square at the Tridente of via del Babuino, via di Ripetta, and via del Corso, with the Flaminio obelisk, twin baroque churches, Santa Maria del Popolo, and Valadier's neoclassical elliptical redesign.
Piazza della Signoria
Piazza della Signoria is Florence's L-shaped civic square before Palazzo Vecchio, formed from 1268 Ghibelline house demolitions; seat of republican government, open-air sculpture gallery with Cellini's Perseus, Ammannati's Neptune, and a David copy.
Piazza Navona
Piazza Navona (Piazza Navona, Rome) is a Baroque square built on the Stadium of Domitian of 86 AD, with Bernini's Fountain of the Four Rivers (1648-1651), Borromini's Sant'Agnese in Agone, and three fountains.
Piazza Ronchi Roman cistern
The Piazza Ronchi Roman cistern (Cisterna di Piazza Ronchi) is a ruined Roman water reservoir in Piazza Ronchi, near the via Prenestina in Rome's Collatino district.
Piazza San Marco
Piazza San Marco, or St Mark's Square, is the principal public square of Venice, Italy, a 170-meter space enclosed by St Mark's Basilica and the Campanile.
Piazzi (lunar crater)
Piazzi is a 102.57-km-wide IAU-approved lunar impact crater at 36.16 degrees south, 68.01 degrees west, named in 1935 for Giuseppe Piazzi, the Italian astronomer who discovered Ceres in 1801.
Pibb Xtra
Pibb Xtra, also known as Mr. Pibb, is Coca-Cola's spicy cherry soft drink launched in 1972 and renamed in 2001; 40 mg caffeine, 140 calories per 12 fl oz, replaced by reformulated Mr. Pibb from 2025.
Pibit.AI
Pibit.AI is an insurtech startup founded in 2020 by Akash Agarwal and headquartered in South San Francisco, California, whose CURE platform automates underwriting for commercial property and casualty insurers.
Pibrentasvir
Pibrentasvir is a pan-genotypic hepatitis C NS5A inhibitor developed by AbbVie and marketed as part of glecaprevir/pibrentasvir, sold as Mavyret and approved by the FDA in 2017.
Pic Boby
Pic Boby (Imarivolanitra), 2,658 m, is Madagascar's second-highest peak, the summit of the Andringitra Massif in Andringitra National Park south of Ambalavao; a non-technical trek over potassic syenite with 1,875 m prominence.
Pic la Selle
Pic la Selle (Pik Lasel, Morne La Selle) is Haiti's highest peak at 2,680 m, in the Chaîne de la Selle range; a probable Black-capped Petrel nesting site in Foret de Pins II National Park.
PIC microcontrollers
PIC microcontrollers, also called PICmicro or Microchip PIC, are a family of microcontrollers developed by General Instrument in the 1970s and made by Microchip since 1989.
Pica (disorder)
Pica (disorder): eating nonfood, nonnutritive substances for at least one month, also called geophagy, amylophagy, pagophagia; DSM-5 eating disorder affecting children, pregnant women, and people with intellectual disability, linked to iron deficiency.
Picabo Street
Picabo Street, born 1971 in Triumph, Idaho, is a retired American alpine ski racer who won Olympic downhill silver in 1994 and Super-G gold in 1998.
Picacho del Diablo
Cerro Picacho del Diablo (Cerro de la Encantada, Big Picacho) is a 3,096 m granite peak in Baja California's Sierra de San Pedro Mártir, the highest point on the Baja California peninsula, first climbed in 1911 by Donald McClain.
Picadillo
Picadillo: Spanish and Latin American dish of seasoned ground or minced meat with tomato, onion, peppers; from picar, to mince. Mexican, Cuban, Filipino giniling, Costa Rican vegetable hash, and Spanish chorizo-meat versions differ.
Picankibart injection
Picankibart injection (匹康奇拜单抗注射液, 信美悦, IBI112) is Innovent Biologics' anti-IL-23p19 monoclonal antibody, the first China-originated IL-23p19 drug, NMPA-approved November 2025 for moderate-to-severe plaque psoriasis with 12-week maintenance dosing.
Picanol
Picanol is a Belgian manufacturer of shuttleless air-jet and rapier weaving machines based in Ieper, Belgium, founded in 1936, with more than 400,000 machines produced.
Picard group
The Picard group Pic(X) of a scheme or ringed space X is the group of isomorphism classes of line bundles on X, with tensor product as the group operation.
Picard iteration
Picard iteration, also called Picard–Lindelöf iteration, is a fixed-point method for solving initial value problems for ordinary differential equations, used mainly to prove that a unique solution exists.
Picard literature
Picard literature is the body of writing in Picard, a Romance langue d'oïl spoken in northern France and Belgian Hainaut, spanning medieval texts, a 17th-century revival, and modern works.
Picard theorem
Picard theorem, a pair of results in complex analysis proved by Charles-Émile Picard in 1879: a non-constant entire function takes every complex value with at most one exception.
Picard–Lindelöf theorem
The Picard–Lindelöf theorem, also called the Cauchy–Lipschitz theorem or Picard's existence theorem, guarantees that an initial value problem for an ordinary differential equation whose right-hand side is Lipschitz continuous has a unique local solution.
Picardi (Martian crater)
Picardi, a Martian impact crater named for Giovanni Picardi, Sapienza University radar scientist and first author of the 2005 Science MARSIS subsurface sounding paper; IAU WGPSN approved the name under the Mars scientist-naming convention.
Picardy
Picardy (Picardie), historical province and former administrative region of northern France (Aisne, Oise, Somme; chef-lieu Amiens), merged into Hauts-de-France on 1 January 2016; known for Gothic cathedrals, Somme valley, and rich agriculture.
Picardy third
Picardy third (tierce de Picardie): a major tonic chord ending a minor-key piece or section, made by raising the chord's third a semitone; common in Renaissance and Baroque music, later used by Chopin, Dvorak, and the Beatles.
Picaresque novel
Picaresque novel (novela picaresca): Spanish Golden Age prose genre, 16th-17th centuries, begun by the anonymous Lazarillo de Tormes (1554), featuring a first-person rogue narrator, episodic survival adventures, and satire, later influencing Tom Jones and Huckleberry Finn.