42,772 articles
Pinhole camera
A pinhole camera is a lensless camera where light through a single tiny aperture forms an inverted image, offering nearly infinite depth of field at the cost of long exposures.
Pink
Pink, also known as the pink color, is a non-spectral color: a pale, desaturated red produced by mixtures of light such as red with white, not by any single wavelength.
Pink noise
Pink noise, also called 1/f noise or flicker noise, is a random signal whose power falls 3 dB per octave, giving equal energy per octave band.
Pinos Altos mine
The Pinos Altos mine is a gold mine in the Sierra Madre of northern Chihuahua, Mexico, owned by Agnico Eagle, producing gold with by-product silver since 2008.
Pint
The pint (pt) is a unit of volume in the British imperial and US customary systems; the US liquid pint is 16 fluid ounces, the imperial pint 20.
Pinwheel Galaxy
The Pinwheel Galaxy, also known as Messier 101, M101, or NGC 5457, is a large face-on spiral galaxy in Ursa Major, about 25 million light-years away.
Pioch-Farrus
Pioch-Farrus (Pioch Farrus), ancient copper mine at Cabrières, Hérault, France, in the Cabrières-Péret district, the oldest known copper mines in France; Chalcolithic radiocarbon date 4310 ± 75 BP, firesetting confirmed, Gallo-Roman and later reuse.
Pion
A pion, or pi meson, is the lightest meson, a subatomic particle made of a quark and antiquark that mediates the strong force binding atomic nuclei.
Pion-decay gamma-ray emission
Pion-decay gamma-ray emission is gamma radiation produced when cosmic-ray protons collide with ambient gas and form neutral pions, and it is the standard signature of hadronic cosmic-ray interactions.
Pioneer plaque
The Pioneer plaques are two engraved gold-anodized aluminum plates attached to Pioneer 10 and 11 in 1972 and 1973, the first physical messages sent out of the solar system.
Piotr E. Marszałek
Piotr E. Marszałek, also published as Piotr Marszalek, is a Polish-trained biophysicist and Duke professor emeritus known for AFM studies of polysaccharide elasticity and protein mechanics.
Piotr Piecuch
Piotr Piecuch is a University Distinguished Professor of chemistry at Michigan State University known for developing renormalized and active-space coupled-cluster methods for bond breaking and excited states.
Piotr Rehbinder
Piotr Aleksandrovich Rehbinder (Пётр Александрович Ребиндер; 1898–1972) was a Soviet physical chemist who discovered the Rehbinder effect in 1928, founded physical-chemical mechanics, and led Soviet colloid chemistry for decades.
Piotr Zelenay
Piotr Zelenay is an electrochemist at Los Alamos National Laboratory, a Laboratory Fellow who has led the Fuel Cell Program since 2000 and is known for platinum-free fuel cell catalysts.
Pipe Nebula
The Pipe Nebula is a large dark molecular cloud in Ophiuchus, about 450 light-years away, visible to the naked eye against the Milky Way's star clouds.
Piperacillin
Piperacillin is a semisynthetic, broad-spectrum ureidopenicillin antibiotic developed by Toyama Chemical, given by injection, active against Pseudomonas aeruginosa, and now used almost entirely with tazobactam as Zosyn or Tazocin.
Piperaquine
Piperaquine is a long-acting bisquinoline antimalarial, structurally related to chloroquine, that is used almost exclusively as the fixed-dose combination with dihydroartemisinin for treating uncomplicated malaria and, in repeated monthly courses, for malaria chemoprevention.
Piperazine
Piperazine, also known as hexahydropyrazine, is an organic compound, C4H10N2, best known as an anthelmintic drug introduced in 1953 that paralyzes intestinal roundworms and is also a widely used CO2 capture promoter.
Piperidine
Piperidine, also called hexahydropyridine, is a saturated six-membered nitrogen heterocycle, a colorless liquid with a pepper-like odor made from pyridine and common in FDA-approved small-molecule drugs.
Pipette
A pipette, or pipettor, is a laboratory instrument that measures and transfers precise liquid volumes; Heinrich Schnitger invented the piston-stroke pipette in 1958, and Eppendorf launched the first industrial version in 1961.
Piranha solution
Piranha solution, also known as piranha etch or SPM clean, is a reactive mix of concentrated sulfuric acid and hydrogen peroxide used to strip organic residues from silicon wafers.
Pirani gauge
A Pirani gauge is a vacuum gauge that infers gas pressure from the thermal conductivity of the gas, using a heated filament in a Wheatstone bridge, invented in 1906 by Marcello Pirani.
Pirelli Calendar
The Pirelli Calendar, also called The Cal, is an annual art photography publication produced since 1964 by the Italian tire maker Pirelli and never sold.
Pirenzepine
Pirenzepine is an M1-selective muscarinic acetylcholine receptor antagonist developed by Dr. Karl Thomae in Germany, marketed as Gastrozepin for peptic ulcers and later trialed as a gel for slowing childhood myopia.
Piri Reis
Piri Reis, born Ahmed Muhiddin Piri, was an Ottoman admiral and cartographer of the 1500s, best known for his 1513 world map and his sailing guide, the Kitab-ı Bahriye.
Pirimicarb
Pirimicarb (C11H18N4O2) is a synthetic carbamate insecticide and acetylcholinesterase inhibitor used mainly as a selective aphicide on cereals, potatoes, vegetables, and fruit, including organophosphate-resistant aphids.
Pisces (astrology)
Pisces, or मीन, is the twelfth sign of the zodiac in Western astrology, represented by two fishes and assigned to birthdays from about February 19 to March 20.
Pisces (constellation)
Pisces is a zodiacal constellation of the northern sky between Aquarius and Aries that contains the vernal equinox point and the spiral galaxy M74; its brightest star is Alpherg.
Pisces I (dwarf galaxy)
Pisces I, also known as LGS 3 or the Pisces Dwarf Galaxy, is a small gas-bearing dwarf galaxy of the Local Group in the constellation Pisces, discovered in 1978.
Piscis Austrinus
Piscis Austrinus, also known as Pisces Australis, is a small, faint southern constellation representing the Southern Fish, dominated by its first-magnitude star Fomalhaut and its famous debris disk.