Scientific News
Articles across mathematics, physics, chemistry, biology, and astronomy.
Science
Definition of life
The precise definition of life is a contested aspect of it, and several proposals have been advanced. Biology defines and studies life as we know it, but abiogenesis and astrobiology seek wider and more encompassing definitions. Abiogenesis is the process by which life develops from inorganic materials, so a definition aims to establish the frontier between inorganic matter and the earliest lifefo
8/24/2026
Science
Degree of parallelism
The degree of parallelism (DOP) is a metric which indicates how many operations can be or are being simultaneously executed by a computer. It is used as an indicator of the complexity of algorithms, and is especially useful for describing the performance of parallel programs and multi-processor systems. A program running on a parallel computer may utilize different numbers of processors at differe
8/24/2026
Science
Definition
A definition is a semantic statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories: intensional definitions (which try to give the sense of a term), and extensional definitions (which try to list the objects that a term describes). Another important category of definitions is the class of ostensive definitions, which con
8/24/2026
Science
Degree of isochronous distortion
The degree of isochronous distortion, in data transmission, is the ratio of the absolute value of the maximum measured difference between the actual and the theoretical intervals separating any two significant instants of modulation (or demodulation), to the unit interval. These instants are not necessarily consecutive. This value is usually expressed as a percentage. The result of the measuremen
8/24/2026
Science
Degeneracy (mathematics)
In mathematics, a degenerate case is a limiting case of a class of objects which appears to be qualitatively different from (and usually simpler than) the rest of the class; "degeneracy" is the condition of being a degenerate case. A given class of objects may be defined by several different systems of equations in most scenarios, and these different systems of equations may lead to different dege
8/24/2026
Science
Definition of planet
The definition of the term planet has changed several times since the word was coined by the ancient Greeks. Greek astronomers employed the term ἀστέρες πλανῆται (asteres planetai), 'wandering stars', for star-like objects which apparently moved over the sky. Over the millennia, the term has included a variety of different celestial bodies, from the Sun and the Moon to satellites and asteroids. In
8/24/2026
Science
Degree (angle)
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a unit of measurement of a plane angle in which one full rotation is assigned the value of 360 degrees. The unit of angular measure in the International System of Units (SI) is the radian, and one degree is equivalent to π/180 radians.
8/24/2026
Science
Defining length
In the field of genetic algorithms, a schema (plural: schemata) is a template that represents a subset of potential solutions. These templates use fixed symbols (e.g., `0` or `1`) for specific positions and a wildcard or "don't care" symbol (often `#` or `*`) for others. The defining length of a schema, denoted as L(H), measures the distance between the outermost fixed positions in the template. A
8/24/2026
Science
Degenerate energy levels
In quantum mechanics, an energy level is degenerate if it corresponds to two or more different measurable states of a quantum system. Conversely, two or more different states of a quantum mechanical system are said to be degenerate if they give the same value of energy upon measurement. The maximum number of linearly independent states corresponding to a particular energy level is known as the deg
8/24/2026
Science
Defense Information System Network
The Defense Information Systems Network (DISN) has been the United States Department of Defense's enterprise telecommunications network for providing data, video, and voice services for 40 years.
8/24/2026
Science
Degree of unsaturation
In the analysis of the molecular formula of organic molecules, the degree of unsaturation (DU) (also known as the index of hydrogen deficiency (IHD), double bond equivalents (DBE), or unsaturation index) is a calculation that determines the total number of rings and π bonds. A formula is used in organic chemistry to help draw chemical structures. It does not give any information about those compon
8/24/2026
Science
Deep-sea exploration
Deep-sea exploration is the investigation of physical, chemical, and biological conditions in the ocean waters and sea bed beyond the continental shelf, for scientific or commercial purposes. Deep-sea exploration is an aspect of underwater exploration and is considered a relatively recent human activity compared to the other areas of geophysical research, as the deeper depths of the sea have been
8/24/2026
Science
Deep-sea community
A deep-sea community is any community of organisms associated with a shared habitat in the deep sea. Deep sea communities remain largely unexplored, due to the technological and logistical challenges and expense involved in visiting this remote biome. Because of the unique challenges (particularly the high barometric pressure, extremes of temperature, and absence of light), it was long believed th
8/24/2026
Science
Defaunation
Defaunation is the global, local, or functional extinction of animal populations or species from ecological communities. The growth of the human population, combined with advances in harvesting technologies, has led to more intense and efficient exploitation of the environment. This has resulted in the depletion of large vertebrates from ecological communities, creating what has been termed "empty
8/24/2026
Science
Definitions of mathematics
Mathematics has no generally accepted definition. Different schools of thought, particularly in philosophy, have put forth radically different definitions. All are controversial.
8/24/2026
Science
Deep scattering layer
The deep scattering layer, sometimes referred to as the sound scattering layer, is a layer in the ocean consisting of a variety of marine animals. It was discovered through the use of sonar, as ships found a layer that scattered the sound and was thus sometimes mistaken for the seabed. For this reason it is sometimes called the false bottom or phantom bottom. It can be seen to rise and fall each d
8/24/2026
Science
Degradation (geology)
In geology, degradation refers to the lowering of a fluvial surface, such as a stream bed or floodplain, through erosional processes. Degradation is the opposite of aggradation. Degradation is characteristic of channel networks in which either bedrock erosion is taking place, or in systems that are sediment-starved and are therefore entraining more material than they are depositing. When a stream
8/24/2026
Science
Degeneracy (biology)
Within biological systems, degeneracy occurs when structurally dissimilar components/pathways can perform similar functions (i.e. are effectively interchangeable) under certain conditions, but perform distinct functions in other conditions. Degeneracy is thus a relational property that requires comparing the behavior of two or more components. In particular, if degeneracy is present in a pair of c
8/24/2026
Science
Deep water cycle
The deep water cycle, or geologic water cycle, involves exchange of water with the mantle, with water carried down by subducting oceanic plates and returning through volcanic activity, distinct from the water cycle process that occurs above and on the surface of Earth. Some of the water makes it all the way to the lower mantle and may even reach the outer core. Mineral physics experiments show tha
8/24/2026
Science
Degree-Rips bifiltration
The degree-Rips bifiltration is a simplicial filtration used in topological data analysis for analyzing the shape of point cloud data. It is a multiparameter extension of the Vietoris–Rips filtration that possesses greater stability to data outliers than single-parameter filtrations, and which is more amenable to practical computation than other multiparameter constructions. Introduced in 2015 by
8/24/2026
Science
Dark matter
In astronomy and cosmology, dark matter is an invisible and hypothetical form of matter that does not interact with electromagnetic radiation, including light. Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed. Such effects occur in the context of formation and evolution of galaxies, gravitational lensi
8/24/2026
Science
Data center
A data center is a physical room, building, or facility for the purpose of the storage, management, and dissemination of data and information, including computer systems, and associated components, housing IT infrastructure, and training artificial intelligence. The Energy Independence and Security Act of 2007 defines a data center as "any facility that primarily contains electronic equipment used
8/24/2026
Science
Data drilling
Data drilling (also drilldown) refers to any of various operations and transformations on tabular, relational, and multidimensional data. The term has widespread use in various contexts, but is primarily associated with specialized software designed specifically for data analysis.
8/24/2026
Science
Dasymeter
A dasymeter is a device that acts as a densimeter used to measure the density of gases. It consists of a thin sphere made of glass, ideally with an average density close to that of the gas to be investigated. This sphere is immersed in the gas and weighed. The dasymeter was initially intended to be a device to demonstrate the buoyant effect of gases like air.
8/24/2026
Science
Dark-sky preserve
A dark-sky preserve (DSP) is an area, usually surrounding a park or observatory, that restricts or reduces light pollution or maintains and protects naturally dark night skies. Different terms have been used to describe these areas as national organizations and governments have worked independently to create programs. DarkSky International (DarkSky) uses "International Dark Sky Reserve" (IDSR) and
8/24/2026
Science
Darwin–Radau equation
In astrophysics, the Darwin–Radau equation (named after Rodolphe Radau and Charles Galton Darwin) gives an approximate relation between the moment of inertia factor of a planetary body and its rotational speed and shape. The moment of inertia factor is directly related to the largest principal moment of inertia, C. It is assumed that the rotating body is in hydrostatic equilibrium and is an elli
8/24/2026
Science
Data binding
In computer programming, data-binding is a general technique that binds data sources from the provider and consumer together and synchronizes them. This is usually done with two data/information sources with different languages, as in XML data binding and UI data binding. In UI data binding, data and information objects of the same language, but different logic function are bound together (e.g., J
8/24/2026
Science
Datakit
In telecommunications, a Datakit is a virtual circuit switch developed by Sandy Fraser at Bell Labs for both local-area and wide-area networks. It is currently used by the Regional Bell Operating Companies (RBOCs) in North America.
8/24/2026
Science
Datasource
A datasource or DataSource is a name given to the connection set up to a database from a server. The name is commonly used when creating a query to the database. The data source name (DSN) need not be the same as the filename for the database. For example, a database file named friends.mdb could be set up with a DSN of school. Then DSN school would be used to refer to the database when performing
8/24/2026
Science
Data verification
Data verification is a process in which different types of data are checked for accuracy and inconsistencies after data migration is done. In some domains it is referred to Source Data Verification (SDV), such as in clinical trials. Data verification helps to determine whether data was accurately translated when data is transferred from one source to another, is complete, and supports processes in
8/24/2026
Science
Database-as-IPC
In computer programming, Database-as-IPC may be considered an anti-pattern where a disk persisted table in a database is used as the message queue store for routine inter-process communication (IPC) or subscribed data processing. If database performance is of concern, alternatives include sockets, network socket, or message queue. British computer scientist, Junade Ali, defined the Database-as-IPC
8/24/2026
Science
Data truncation
In databases and computer networking data truncation occurs when data or a data stream (such as a file) is stored in a location too short to hold its entire length. Data truncation may occur automatically, such as when a long string is written to a smaller buffer, or deliberately, when only a portion of the data is wanted. Depending on what type of data validation a program or operating system ha
8/24/2026
Science
Astroinformatics
Astroinformatics is an interdisciplinary field of study involving the combination of astronomy, data science, machine learning, informatics, and information/communications technologies. The field is closely related to astrostatistics. Data-driven astronomy (DDA) refers to the use of data science in astronomy. Several outputs of telescopic observations and sky surveys are taken into consideration a
8/24/2026
Science
Datiscoside
Datiscoside is any one of several chemical compounds isolated from certain plants, notably Datisca glomerata. They can be seen as derivatives of the triterpene hydrocarbon cucurbitane (C30H54), more specifically from cucurbitacin F. They include: Datiscoside B, from D. glomerata Datiscoside D, from D. glomerata Datiscoside H, from D. glomerata
8/24/2026
Science
Data processing inequality
The data processing inequality is an information theoretic concept that states that the information content of a signal cannot be increased via a local physical operation. This can be expressed concisely as 'post-processing cannot increase information'.
8/24/2026
Science
Dataism
Dataism is a term that has been used to describe the mindset or philosophy created by the emerging significance of big data. It was first used by David Brooks in The New York Times in 2013. The term has been expanded to describe what historian Yuval Noah Harari, in his book Homo Deus: A Brief History of Tomorrow from 2015, calls an emerging ideology or even a new form of religion, in which "inform
8/24/2026
Science
Database repair
The problem of database repair is a question about relational databases which has been studied in database theory, and which is a particular kind of data cleansing. The problem asks about how we can "repair" an input relational database in order to make it satisfy integrity constraints. The goal of the problem is to be able to work with data that is "dirty", i.e., does not satisfy the right integr
8/24/2026
Science
Datenklo
The Datenklo (German; lit. 'data toilet') or CCC-Modem was an acoustic coupler modem in the early 1980s for which the Chaos Computer Club made plans and schematics available. The name refers to the use of readily available toilet plumbing cuffs to fit the telephone receiver. The meaning of the name changed in the 1990s, when portable toilet cubicles were re-purposed to provide connectivity at hack
8/24/2026
Science
Data minimization
Data minimization is the principle of collecting, processing and storing only the necessary amount of personal information required for a specific purpose. The principle emanates from the realisation that processing unnecessary data is creating unnecessary risks for the data subject without creating any current benefit or value. The risks of processing personal data vary from identity theft to unr
8/24/2026
Science
Dark oxygen
Dark oxygen production refers to the generation of molecular oxygen (O2) through processes that do not involve light-dependent oxygenic photosynthesis. While the majority of Earth's oxygen is produced via photosynthesis, dark oxygen production occurs via a variety of abiotic and biotic processes and may support aerobic metabolism in dark, anoxic environments. The theory for dark oxygen production
8/24/2026
Science
De vetula
De vetula ("On the Old Woman") is a long 13th-century elegiac comedy written in Latin. It is pseudepigraphically signed "Ovidius", and in its time was attributed to the classical Latin poet Ovid. It consists of three books of hexameters, and was quoted by Roger Bacon. In its slight plot, the aging Ovid is duped by a go-between, and renounces love affairs. Its interest to modern readers lies in the
8/24/2026
Science
De Bruijn–Newman constant
The de Bruijn–Newman constant, denoted by Λ {\displaystyle \Lambda } and named after Nicolaas Govert de Bruijn and Charles Michael Newman, is a mathematical constant defined via the zeros of a certain function H ( λ , z ) {\displaystyle H(\lambda ,z)} , where
8/24/2026
Science
De Laval nozzle
A de Laval nozzle (or convergent–divergent nozzle, CD nozzle or con–di nozzle) is a tube that is pinched in the middle with a rapid convergence and gradual divergence. It is used to accelerate a compressible fluid to supersonic speeds in the axial (thrust) direction, by converting the thermal energy of the flow into kinetic energy. De Laval nozzles are widely used in some types of steam turbines a
8/24/2026
Science
De revolutionibus orbium coelestium
De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) is the seminal work on the heliocentric theory of the astronomer Nicolaus Copernicus (1473–1543 CE). The book, first printed in 1543 CE in Nuremberg, Holy Roman Empire, offered an alternative model of the universe to Ptolemy's geocentric system, which had been widely accepted since ancient times.
8/24/2026
Science
David Musser
David "Dave" Musser is a professor emeritus of computer science at the Rensselaer Polytechnic Institute in Troy, New York, United States. He is known for his work in generic programming, particularly as applied to C++, and his collaboration with Alexander Stepanov. Their work together includes coining the term "generic programming" in Musser & Stepanov (1989), and led to the creation of the C++ St
8/24/2026
Science
De Sitter effect
In astrophysics, the term de Sitter effect (named after the Dutch physicist Willem de Sitter) has been applied to two unrelated phenomena: De Sitter double star experiment De Sitter precession – also known as geodetic precession or the geodetic effect
8/24/2026
Science
De novo domestication
De novo domestication is a process where new species are genetically altered to meet human needs, such as agriculture or companionship. It is performed both by farmers and scientists, and can be done through traditional selective breeding or modern biotechnological methods. Targets for de novo domestication are often species that have never been under cultivation, but may also include wild relativ
8/24/2026
Science
De Vaucouleurs's law
In astronomy, de Vaucouleurs's law, also known as the de Vaucouleurs profile or de Vaucouleurs model, describes how the surface brightness I {\displaystyle I} of an elliptical galaxy varies as a function of apparent distance R {\displaystyle R} from the center of the galaxy: ln
8/24/2026
Science
De-asphalter
A de-asphalter is a unit in a crude oil refinery or bitumen upgrader that separates asphalt from the residuum fraction of crude oil or bitumen. The primary purpose of the separation is to remove contaminants (asphaltenes, metals) from the feed that would cause rapid deactivation of catalysts in downstream processing units. In doing so, the de-asphalter is the first step in a series of processes th
8/24/2026
Science
Davidson Seamount
Davidson Seamount is a seamount (underwater volcano) located off the coast of Central California, 80 mi (129 km) southwest of Monterey and 75 mi (121 km) west of San Simeon. At 26 mi (42 km) long and 8 mi (13 km) wide, it is one of the largest known seamounts in the world. From base to crest, the seamount is 7,480 ft (2,280 m) tall, yet its summit is still 4,101 ft (1,250 m) below the sea surface.
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