In logic and related fields such as mathematics and philosophy, "if and only if" is a biconditional logical connective between statements, where either both statements are true or both are false.
Q, or q, is the seventeenth letter of the modern English alphabet and the ISO basic Latin alphabet. Its name in English is cue, plural cues.
In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean of the set, while a high standard deviation indicates that the values are spread out over a wider range.
An electric field is the physical field that surrounds electrically-charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field for a system of charged particles. Electric fields originate from electric charges, or from time-varying magnetic fields. Electric fields and magnetic fields are both manifestations of the electromagnetic force, one of the four fundamental forces of nature.
In mathematics, the quaternion number system extends the complex numbers. Quaternions were first described by Irish mathematician William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space. Hamilton defined a quaternion as the quotient of two directed lines in a three-dimensional space, or, equivalently, as the quotient of two vectors. Multiplication of quaternions is noncommutative.
The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first stated by Benoît Paul Émile Clapeyron in 1834 as a combination of the empirical Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law. The ideal gas law is often written in an empirical form:
The Dead Sea Scrolls are ancient Jewish and Hebrew religious manuscripts that were found in the Qumran Caves in the Judaean Desert, near Ein Feshkha on the northern shore of the Dead Sea in the West Bank, and the last discovered scrolls found in the Cave of Horror in Israel. In the larger sense, the Dead Sea Scrolls include manuscripts from additional Judaean Desert sites, dated as early as the 8th century BCE and as late as the 11th century CE.
Exclusive or or exclusive disjunction is a logical operation that is true if and only if its arguments differ.
In Islam, ʿĪsā ibn Maryam, or Jesus, is the penultimate prophet and messenger of God (Allah) and the Messiah, who was sent to guide the Children of Israel with a new revelation: Injīl.
Hamiltonian mechanics is a mathematically sophisticated formulation of classical mechanics. Historically, it contributed to the formulation of statistical mechanics and quantum mechanics. Hamiltonian mechanics was first formulated by William Rowan Hamilton in 1833, starting from Lagrangian mechanics, a previous reformulation of classical mechanics introduced by Joseph Louis Lagrange in 1788. Like Lagrangian mechanics, Hamiltonian mechanics is equivalent to Newton's laws of motion in the framework of classical mechanics.
This gallery of sovereign state flags shows the national or state flags of sovereign states that appear on the list of sovereign states. For other flags, please see flags of active autonomist and secessionist movements, flags of extinct states and gallery of flags of dependent territories. Each flag is depicted as if the flagpole is positioned on the left of the flag, except for those of Iran, Iraq and Saudi Arabia which are depicted with the hoist to the right.
Q was a popular music magazine published monthly in the United Kingdom. It was founded in 1986 by broadcast journalists Mark Ellen and David Hepworth, who were presenters of the BBC television music series Whistle Test.
Kamaal Ibn John Fareed, better known by his stage name Q-Tip, is an American rapper, record producer, singer, actor and DJ. Nicknamed The Abstract, he is noted for his innovative jazz-influenced style of hip hop production and his philosophical, esoteric and introspective lyrical themes. He embarked on his music career in the late 1980s, as an MC and main producer of the influential alternative hip hop group A Tribe Called Quest. In the mid-1990s, he co-founded the production team The Ummah, followed by the release of his gold-certified solo debut Amplified in 1999. In the 2000s, he released the Grammy Award-nominated album The Renaissance and the experimental album Kamaal the Abstract.
The De Havilland Canada DHC-8, commonly known as the Dash 8, is a series of turboprop-powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. DHC was later bought by Boeing in 1988, then by Bombardier in 1992; then by Longview Aviation Capital in 2019, reviving the de Havilland Canada brand. Powered by two Pratt & Whitney Canada PW100s, it was developed from the Dash 7 with improved cruise performance and lower operational costs, but without STOL performance. Three sizes were offered: initially the 37–40 seat -100 until 2005 and the more powerful -200 from 1995, the stretched 50–56 seats -300 from 1989, both until 2009, and the 68–90 seats -400 from 1999, still in production. The Q Series are post-1997 variants fitted with active noise control systems.
In linear algebra, a rotation matrix is a transformation matrix that is used to perform a rotation in Euclidean space. For example, using the convention below, the matrix
B&Q Limited is a British multinational DIY and home improvement retailing company, headquartered in Eastleigh, United Kingdom, and is a wholly owned subsidiary of Kingfisher plc. Founded by Richard Block and David Quayle in 1969 originally as Block & Quayle, the retail chain offers over 40,000 products across 300 physical stores and online shops.
QAnon, or simply Q, is a discredited far-right conspiracy theory alleging that a cabal of Satanic, cannibalistic pedophiles run a global child sex trafficking ring and conspired against former President Donald Trump during his term in office. QAnon is commonly described as a cult.
In mathematics, a rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. For example, −3/7 is a rational number, as is every integer. The set of all rational numbers, also referred to as "the rationals", the field of rationals or the field of rational numbers is usually denoted by a boldface Q ; it was thus denoted in 1895 by Giuseppe Peano after quoziente, Italian for "quotient".
Coulomb's law, or Coulomb's inverse-square law, is an experimental law of physics that quantifies the amount of force between two stationary, electrically charged particles. The electric force between charged bodies at rest is conventionally called electrostatic force or Coulomb force. The law was first discovered in 1785 by French physicist Charles-Augustin de Coulomb, hence the name. Coulomb's law was essential to the development of the theory of electromagnetism, maybe even its starting point, as it made it possible to discuss the quantity of electric charge in a meaningful way.
Wikidata is a collaboratively edited multilingual knowledge graph hosted by the Wikimedia Foundation. It is a common source of open data that Wikimedia projects such as Wikipedia, and anyone else, can use under the CC0 public domain license. Wikidata is a wiki powered by the software MediaWiki, and is also powered by the set of knowledge graph MediaWiki extensions known as Wikibase.
