All articles starting with E
17,681 articles
Euclid (spacecraft)
Euclid, also called the Euclid space telescope, is a European Space Agency telescope launched in 2023 to map billions of galaxies and study dark energy and dark matter.
Euclid (Εὐκλείδης)
Euclid, also known as Euclid of Alexandria (Εὐκλείδης), was a Greek mathematician active about 300 BC whose thirteen-book Elements became the model of rigorous mathematics for two millennia.
Euclid Labs, Inc.
Euclid Labs, Inc. is a San Francisco technology startup founded in 2021 that operates Magic Eden, an NFT marketplace, and raised over $180 million across SEC filings.
EUCLID trial
EUCLID (Examining Use of Ticagrelor in PAD, NCT01732822) was an AstraZeneca-funded randomized trial in 13,885 patients with symptomatic peripheral artery disease comparing ticagrelor 90 mg twice daily with clopidogrel 75 mg daily; ticagrelor was not superior (10.8% vs 10.6%, HR 1.02).
Euclid's Elements
Euclid's Elements (Greek: Stoicheia) is a 13-book mathematical treatise from the 3rd century BC that presents geometry, number theory, and proportion as a deductive system and became the model for mathematical writing.
Euclid's lemma
Euclid's lemma, also called Euclid's first theorem, states that a prime dividing a product of two integers must divide one factor, and it proves unique prime factorization.
Euclid's theorem
Euclid's theorem, on the infinitude of primes, states that there are infinitely many prime numbers; Euclid proved it around 300 BC as Proposition 20 of Book IX of the Elements.
Euclidean algorithm
The Euclidean algorithm, also called Euclid's algorithm, is a procedure for finding the greatest common divisor of two integers, described by Euclid around 300 BC.
Euclidean distance
Euclidean distance, or Pythagorean metric, is the ordinary straight-line distance between two points in Euclidean space, the square root of the sum of squared coordinate differences.
Euclidean division
Euclidean division, also called division with remainder, is the theorem that dividing one integer by a nonzero integer yields a unique quotient and remainder smaller than the divisor.
Euclidean domain
A Euclidean domain is an integral domain with a Euclidean norm allowing division with remainder, as in the integers, so the Euclidean algorithm computes greatest common divisors.
Euclidean geometry
Euclidean geometry, also known as plane or classical geometry, is the system derived from the axioms of Euclid's Elements, a Greek work of around 300 BC that shaped mathematics for two millennia.
Euclidean group
The Euclidean group E(n), also denoted ISO(n), is the group of all distance-preserving transformations of n-dimensional Euclidean space, made up of rotations, translations, reflections, and their compositions.
Euclidean norm
The Euclidean norm, also called the 2-norm, is the square root of the sum of a vector's squared coordinates, and it measures the vector's length.
Euclidean quantum gravity
Euclidean quantum gravity is an approach to quantizing gravity in which the path integral runs over Riemannian metrics, originating with Hawking and the Hartle–Hawking no-boundary proposal.
Euclidean signed distance field
A Euclidean signed distance field (ESDF) is a spatial map storing each point's signed distance to the nearest obstacle surface, used in robot motion planning.
Euclidean space
Euclidean space is the mathematical structure formalizing the familiar geometry of the plane and three-dimensional space, using distances and angles measured by an inner product.
Euclidean vector
A Euclidean vector, also called a spatial or geometric vector, is a quantity with magnitude and direction, drawn as an arrow with length and direction but no fixed location.
Euclides da Cunha
Euclides da Cunha, full name Euclides Rodrigues da Cunha (1866 to 1909), was a Brazilian writer whose classic Os Sertões (1902) recounts the Canudos campaign.
Euclyd
Euclyd is a Dutch semiconductor startup founded in 2024 in Eindhoven by Bernardo Kastrup and Atul Sinha that designs AI inference chips and raised over €200 million in 2026.
Eucommia ulmoides
Eucommia ulmoides (杜仲), the gutta-percha tree, is a hardy rubber tree from central and southern China, the sole species of its family and long used in traditional Chinese medicine.
Eucratides I (Εὐκρατίδης)
Eucratides I (Εὐκρατίδης), Eucratides Megas, Greco-Bactrian king c. 170/171–145 BCE who seized Bactria from the Euthydemids, campaigned to the Jhelum, minted the 169.2 g 20-stater gold coin, and was assassinated by his son Heliocles I.
Euctenizidae
Euctenizidae, wafer-lid or folding-door trapdoor spiders, a North American mygalomorph spider family of 8 genera and 79 species, split from Cyrtaucheniidae in 2012, building thin wafer trapdoors on 10–30 cm burrows.
Eudaimonia (εὐδαιμονία)
Eudaimonia (εὐδαιμονία), also eudemonia, is the ancient Greek ethical term for human flourishing or living well, the supreme good for Aristotle and the Stoics, defined as virtuous activity of the soul, and now a central concept in positive psychology.
Eudald Carbonell
Eudald Carbonell i Roura, born 1953 in Ribes de Freser, Spain, is a Spanish archaeologist and paleontologist known for co-directing the Sierra de Atapuerca excavations.
Euderus set
Euderus set, the crypt-keeper wasp, is a eulophid parasitoid described in 2017 that manipulates the gall wasp Bassettia pallida into plugging its gall exit hole with its head, then emerges through the host's head capsule.
Eudicots
Eudicots (tricolpates): the largest clade of flowering plants, defined by three-apertured (tricolpate) pollen; includes core eudicots with rosids and asterids; recognized in APG IV and APG V classifications.
Eudocimus
Eudocimus is a genus of ibises with two living species, the American white ibis and the scarlet ibis, native to warm regions of the New World.
Eudocimus ruber
Eudocimus ruber, the scarlet ibis (guará, corocoro rojo), is a scarlet-plumaged Threskiornithidae wader of northern South America and the Caribbean; its species rank versus the white ibis is disputed, its color comes from dietary carotenoids, and it is Trinidad and Tobago's national bird.
Eudora Welty
Eudora Welty (1909–2001), Jackson, Mississippi author and photographer, wrote The Optimist's Daughter (1973 Pulitzer Prize), Delta Wedding, and One Writer's Beginnings; first living writer in Library of America.