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Neodymium glass laser
A neodymium glass laser is a solid-state laser in which neodymium ions dissolved in glass emit light near 1.06 µm, first demonstrated by Elias Snitzer in 1961.
Neodymium magnet
The neodymium magnet, also called NdFeB or NIB magnet, is the strongest permanent magnet made, an alloy of neodymium, iron, and boron used in EV motors and wind turbines.
Neodymium(III) oxide
Neodymium(III) oxide, also called neodymia or neodymium sesquioxide, is an inorganic compound (Nd₂O₃), a gray to blue powder used in permanent magnets, glass, lasers, and catalysts.
Neogene
The Neogene, formerly called the Upper Tertiary, is the middle period of the Cenozoic Era, spanning 23.03 to 2.58 million years ago and comprising the Miocene and Pliocene.
Neoglaciation
Neoglaciation is the late Holocene interval, beginning roughly 5,000 years ago, when alpine glaciers regrew after Middle Holocene shrinkage; Porter and Denton formalized the concept in 1967.
Neon
Neon, chemical symbol Ne, is a colorless, odorless noble gas with atomic number 10 that glows reddish orange in discharge tubes, the glow behind neon signs.
Neon lighting
Neon lighting, also called neon tube lighting, is electric lighting in which glass tubes of neon gas glow orange-red under high voltage, first shown by Georges Claude in 1910.
Neon sign
A neon sign is an illuminated sign made of sealed glass tubes filled with low-pressure gas that glows when high-voltage current passes through, commercialized by French engineer Georges Claude.
Neopentane
Neopentane, also called 2,2-dimethylpropane or tetramethylmethane, is the most branched pentane isomer, a C₅H₁₂ hydrocarbon with a central carbon bonded to four methyl groups that boils at 9.5 °C and is a gas at room temperature.
Neopentyl glycol
Neopentyl glycol (NPG, 2,2-dimethylpropane-1,3-diol) is a white crystalline diol used as a building block for polyester, polyurethane, and alkyd resins, synthetic lubricants, and plasticizers, whose quaternary carbon gives polymers high hydrolytic stability and weather resistance.
Neoprene
Neoprene (polychloroprene, first sold as DuPrene) is a synthetic rubber introduced by DuPont in 1931, the first produced commercially, valued for oil, ozone, and flame resistance.
Neoproterozoic
The Neoproterozoic, also called the Late Proterozoic, is the last era of the Proterozoic eon, spanning 1 billion to 539 million years ago and ending at the Cambrian.
Neotame
Neotame (E 961, INS 961, brand Newtame) is an aspartame-derived high-intensity sweetener 7,000-13,000 times sweeter than sucrose, FDA-approved in 2002, with JECFA ADI 0-2 mg/kg bw and EFSA re-evaluated as safe in 2025.
NEOWISE
NEOWISE, the Near-Earth Object Wide-field Infrared Survey Explorer, was NASA's asteroid-hunting reactivation of the WISE infrared telescope, which detected over 3,000 near-Earth objects from 2013 to 2024.
Nepal Sambat
Nepal Sambat (नेपाल संवत्) is Nepal's traditional lunisolar calendar, counted from 879 CE and kept by the Newars; its new year begins with Mha Puja.
Nepalese customary units of measurement
Nepalese customary units of measurement, also called Nepalese units of measurement, are traditional units of which land units like Ropani and Bigha remain officially used despite metrication in 1968.
Nepheline
Nepheline is a rock-forming feldspathoid mineral, Na3K(Al4Si4O16), that forms in silica-deficient magmas and is common in the igneous rock nepheline syenite, a raw material for glass and ceramics.
Nephrite
Nephrite, also known as nephrite jade or Nefrite, is one of the two minerals called jade, a tough amphibole rock that is the jade of ancient China and Māori New Zealand.
Nephrology (institution)
Nephrology (Carlton, Vic.), ISSN 1320-5358 print and 1440-1797 online, is an Australian peer-reviewed nephrology journal published since 1995 by Blackwell Science and later Wiley, indexed in MEDLINE since 2003.
Neptune
Neptune is the eighth and most distant planet of the solar system, an ice giant found in 1846 through mathematical prediction and flown past by Voyager 2 in 1989.
Neptunium
Neptunium, symbol Np, is a radioactive silvery metal with atomic number 93, the first transuranium element, synthesized at Berkeley in 1940 and named after the planet Neptune.
Nereid (moon)
Nereid, also known as Neptune II, is the third-largest moon of Neptune, discovered by Gerard Kuiper in 1949 and famous for one of the most eccentric orbits of any moon.
Nergis Mavalvala
Nergis Mavalvala is a Pakistani-American astrophysicist at MIT, born in Karachi, who worked on LIGO's first direct detection of gravitational waves and serves as Dean of the MIT School of Science.
Nernst effect
The Nernst effect, also called the Nernst–Ettingshausen effect, converts a heat current into a voltage perpendicular to the heat flow in a conductor under a magnetic field.
Nernst equation
The Nernst equation, also known as Nernst's law, is the electrochemical relation giving an electrode's equilibrium potential from its standard potential, temperature, and the activities of reacting species.
Nernst–Planck equation
The Nernst–Planck equation is a continuum model predicting the flux of dissolved charged species under diffusion, migration, and convection, standard in battery, membrane, and nanopore simulations.
Néron model
The Néron model, or Néron minimal model, is a smooth group scheme extending an abelian variety so every rational point extends, introduced by André Néron in 1964.
Nervonic acid
Nervonic acid is a monounsaturated very long-chain fatty acid that is a structural component of myelin in the mammalian central nervous system and is richest in Malania oleifera seed oil.
Nesmith Ankeny
Nesmith Cornett Ankeny (1927–1993) was an American analytic number theorist and MIT professor, known for his 1952 bound on the least quadratic non-residue and the Ankeny–Artin–Chowla conjecture.
Neso
Neso (Neptune XIII, S/2002 N 4) is a small retrograde irregular moon of Neptune discovered in 2002 with the Blanco telescope. It orbits about 48.4 million km out with a 9,374-day period, eccentricity 0.495, and may be a fragment of a broken larger moon.