Technology
Tools, computing and engineering
Articles in this category are re-verified roughly every 30 days.
Technology
3D printing
3D printing, also called additive manufacturing, makes a physical object by adding and joining material in successive layers according to a digital design. Processes use different materials and techniques, including extruding thermoplastic filament, curing liquid resin, or fusing powder. The technology is useful for rapid prototyping, customized products and complex parts, and has applications from manufacturing tools to medical devices. Its benefits depend on the job: print speed, material choices, part size, quality control and cost can limit its use, particularly for high-volume production.
Updated 16 Oct 2026
Technology
Aadhaar
Aadhaar is India's national digital identity system, administered by the Unique Identification Authority of India (UIDAI). After enrolment and verification, a resident is assigned a unique 12-digit number associated with demographic and biometric records. Aadhaar can be used for identity authentication and service delivery, but it is not proof of citizenship or domicile. Its legal framework, use in public and private services, and privacy safeguards have been shaped by legislation and court decisions.
Updated 31 Oct 2026
Technology
Antikythera mechanism
The Antikythera mechanism is a fragmentary ancient Greek device of interlocking bronze gears that calculated and displayed astronomical cycles. Built around the late second or early first century BCE, it could track the Sun and Moon, lunar phases and calendar cycles, and indicate periods when eclipses were likely. Its complexity makes it a major surviving example of ancient mechanical astronomy, although much of its original design and purpose remains uncertain.
Updated 19 Oct 2026
Technology
Artificial intelligence
Artificial intelligence (AI) is a broad field of computing concerned with systems that infer outputs—such as predictions, recommendations, decisions or generated content—from inputs and objectives. AI includes different approaches and applications, from language and image processing to decision support and robotics; its expanding use brings questions about reliability, fairness, privacy and human oversight.
Updated 12 Oct 2026
Technology
Aviation
Aviation is the field and practice of designing, building, operating and maintaining aircraft and the systems that support flight. It includes civil activities such as airline transport, cargo, business and recreational flying, as well as military aviation. Since the first powered, controlled flights of heavier-than-air craft in the early 20th century, aviation has become a global network shaped by aerodynamics, engineering, safety systems, air-traffic coordination and environmental concerns.
Updated 15 Oct 2026
Technology
Battery passport
A battery passport is a digital record linked to an identifiable battery that provides structured information about its model and, where required, the individual battery. Under the European Union Batteries Regulation, from 18 February 2027 passports are required for light means of transport batteries, industrial batteries above 2 kWh, and electric-vehicle batteries placed on the market or put into service in the EU. The record is accessed through a QR code and includes information with different access levels to support transparency, repair, reuse and recycling.
Updated 6 Nov 2026
Technology
Bayesian network
A Bayesian network is a probabilistic graphical model that represents a joint probability distribution using a directed acyclic graph and conditional probability distributions. Nodes represent variables, arrows encode dependencies, and the graph expresses conditional-independence assumptions that can make complex probability models more compact. Bayesian networks support inference from observed evidence, but their arrows do not necessarily represent causes unless additional causal assumptions are justified.
Updated 30 Oct 2026
Technology
Bessemer process
The Bessemer process was a nineteenth-century method for producing steel by blowing air through molten pig iron. The oxygen in the blast oxidized impurities, and the reactions generated heat that helped keep the metal molten. Developed independently by Henry Bessemer in Britain and William Kelly in the United States, the method made large-scale steel production less costly and helped transform construction and rail transport. Its original form worked best with low-phosphorus iron; later processes addressed that limitation, and oxygen steelmaking eventually superseded it.
Updated 22 Oct 2026
Technology
Bhadla Solar Park
Bhadla Solar Park is a large utility-scale solar power development in Rajasthan, India. Built in phases in the arid Thar region, it combines multiple photovoltaic projects with transmission infrastructure and illustrates both the scale of India's solar expansion and the land and resource questions associated with such projects.
Updated 10 Nov 2026
Technology
Blockchain
A blockchain is a type of distributed digital ledger in which records are grouped into blocks and linked cryptographically in sequence. Copies are maintained by participating computers, which follow shared rules to validate updates. Blockchains can be open to anyone or restricted to authorized participants; their design can support shared recordkeeping, but also introduces trade-offs in governance, privacy, speed, and resource use.
Updated 18 Oct 2026
Technology
Carbon Capture and Storage
Carbon capture and storage (CCS) is a group of technologies that separates carbon dioxide from industrial or energy-related gas streams—or, in direct-air systems, from ambient air—then transports it for injection into deep geological formations. It is intended to keep the captured carbon contained over long periods. Its climate value depends on the source of the CO₂, the emissions and energy required across the process, the durability of storage and careful site management.
Updated 21 Oct 2026
Technology
Carbon nanotube
A carbon nanotube is a cylindrical nanostructure formed from a graphene-like network of carbon atoms. Single-walled and multi-walled forms differ in the number of carbon layers, while a tube’s diameter and atomic arrangement influence its properties. Research explores nanotubes in electronics, composites, sensing and other technologies, though performance depends on structure, production and processing.
Updated 31 Oct 2026
Technology
Cloud Computing
Cloud computing provides computing resources and software over a network from shared, configurable systems that can be provisioned on demand. Its common service models—software, platform and infrastructure as a service—and deployment models—public, private, community and hybrid—describe different ways to deliver and manage those resources. Elastic capacity can be useful, but cost, security, reliability and data portability depend on the workload and service arrangement.
Updated 17 Oct 2026
Technology
CRISPR-Cas9
CRISPR-Cas9 is a genome-editing technology adapted from a bacterial defense system. A guide RNA directs the Cas9 enzyme to a chosen DNA sequence, where it can cut the DNA; the cell’s repair processes then help produce a genetic change. The method is widely used in biological research and is being studied for applications in agriculture and medicine, but its precision and outcomes must be assessed for each use.
Updated 21 Oct 2026
Technology
Cryptography
Cryptography is the mathematical discipline of protecting information by transforming it so that unauthorized parties cannot read it, misuse it, or alter it undetected. Modern cryptographic systems support confidentiality, data integrity and authentication through tools such as symmetric encryption, public-key algorithms, hash functions and digital signatures. Their security depends not only on algorithm design but also on sound implementation and careful management of cryptographic keys.
Updated 14 Oct 2026
Technology
Cybersecurity
Cybersecurity is the practice of managing risks to digital information, devices, networks and services. It combines technical safeguards, organizational policies and preparedness to reduce unauthorized access, disclosure, alteration or disruption. Because no single measure removes every risk, effective programs identify important assets and weaknesses, protect systems, detect incidents and plan how to respond and recover.
Updated 13 Oct 2026
Technology
Differential Privacy
Differential privacy is a mathematical framework for bounding how much a data analysis can depend on any one person’s information. A randomized mechanism is designed so that its output distributions remain similar for datasets differing in a defined privacy unit. Its parameters describe the strength of the guarantee, while added noise creates a trade-off between privacy and accuracy; repeated releases and implementation choices also matter.
Updated 22 Oct 2026
Technology
Domain Name System
The Domain Name System (DNS) is the Internet’s distributed, hierarchical naming system. It lets computers find records associated with domain names, including host addresses and mail-routing information. By delegating authority among zones and caching answers, DNS supports a global namespace without requiring one central file of every host name and address.
Updated 20 Oct 2026
Technology
Friction stir welding
Friction stir welding (FSW) is a solid-state joining process in which a rotating, non-consumable tool heats and stirs the material along a joint without melting it. The softened material is forged behind the moving tool to form a bond. Developed at TWI in 1991, the process is used especially for aluminium alloys and has applications in aerospace, transport, marine and other manufacturing sectors.
Updated 27 Oct 2026
Technology
Geodesic dome
A geodesic dome is a curved, shell-like structure built from a network of triangular or polygonal elements. Its framework distributes stresses through connected members, allowing some designs to enclose broad spaces with comparatively light materials. Zeiss engineer Walther Bauersfeld used a geodesic steel lattice for an early planetarium dome in the 1920s; R. Buckminster Fuller later developed and popularized the form and received a related U.S. patent in 1954.
Updated 21 Oct 2026
Technology
Global Positioning System
The Global Positioning System (GPS) is a United States-owned satellite navigation system that provides positioning, navigation and timing services around the world. Satellites broadcast one-way radio signals containing timing and orbital information; receivers use signals from multiple satellites to calculate location and time. The system combines an orbital constellation, a ground control network and user receivers, and supports applications ranging from everyday navigation to aviation and precise timekeeping.
Updated 13 Oct 2026
Technology
Goubau line
A Goubau line is a single-conductor transmission line that guides high-frequency electromagnetic energy along a wire or other conductor as a surface wave. A dielectric coating or suitable surface structure can help confine the field near the conductor, allowing radio-frequency energy to travel without a conventional two-conductor cable. Researchers have investigated the line for microwave transmission and sensing, though practical performance depends on how the wave is launched, conductor properties, frequency and surrounding environment.
Updated 29 Oct 2026
Technology
Green hydrogen
Green hydrogen is hydrogen produced using renewable energy, most commonly by splitting water through electrolysis powered by renewable electricity. It can replace fossil-derived hydrogen in some industrial processes and serve as a fuel or energy carrier, but its climate benefits depend on electricity sources, production methods and lifecycle emissions. Scaling it requires renewable power, electrolysers, storage and transport infrastructure, as well as suitable end uses.
Updated 1 Nov 2026
Technology
Holography
Holography is a family of methods for recording and reconstructing wavefronts. In optical holography, light scattered from an object interferes with a coherent reference beam, producing a pattern that encodes information about the light's phase as well as its intensity. When properly illuminated, that pattern diffracts light to recreate a wavefront, giving a view with depth and parallax. Dennis Gabor developed the idea in 1947–48 while seeking to improve electron microscopy; lasers later made more practical optical holograms possible. Holography is used in precision measurement, nondestructive testing, scientific imaging and security features, although practical methods have specific illumination and stability requirements.
Updated 17 Oct 2026
Technology
Hydropower
Hydropower, or hydroelectric power, generates electricity from the energy of moving water. Facilities may store water behind a dam, divert part of a river, or pump water between reservoirs to store energy for later use. Hydropower can provide flexible electricity, but projects depend on local water conditions and can alter rivers, ecosystems and human communities; their effects vary with design, location and operation.
Updated 13 Oct 2026
Technology
India Stack
India Stack is a term for India's interconnected digital public infrastructure, including systems and open interfaces for digital identity, payments and data exchange. Built through a combination of public platforms, standards and services, it enables government, financial and other services to interoperate at population scale. The ecosystem has expanded over time, while raising continuing questions about access, privacy, security and governance.
Updated 8 Nov 2026
Technology
Internet
The Internet is a global system of interconnected computer networks that exchange data using shared protocols. Its architecture links independently operated networks through communication links and routers, while services such as email and the World Wide Web make use of that infrastructure. Emerging from late-20th-century networking research, it became a widely used platform for communication, information sharing, research, commerce and collaboration.
Updated 12 Oct 2026
Technology
Internet of Things
The Internet of Things (IoT) is a broad term for physical objects equipped to sense, process or exchange data over communication networks. Examples range from health monitors and household devices to connected vehicles and industrial sensors; their usefulness and risks depend on how data, software and security are managed.
Updated 19 Oct 2026
Technology
Jacquard loom
The Jacquard loom is a weaving loom fitted with a mechanism that uses a linked sequence of punched cards to control individual warp threads. By encoding a pattern in the holes, it could repeatedly weave intricate designs with less need for a draw boy to lift threads by hand. Demonstrated in France in 1801 and patented by Joseph-Marie Jacquard in 1804, its card-based control later influenced the history of computing.
Updated 21 Oct 2026
Technology
Laser
A laser is a device that amplifies light through stimulated emission of radiation, usually producing a highly coherent beam with a narrow range of wavelengths. Since the first operating laser was demonstrated in 1960, lasers have become tools for communication, measurement, research, medicine and manufacturing; their concentrated beams also require appropriate safety controls.
Updated 17 Oct 2026
Technology
LiDAR
LiDAR (light detection and ranging) is an active remote-sensing technique that measures distance using pulses of laser light. By combining the travel time of reflected pulses with information about a sensor's position and orientation, a system can build a three-dimensional point cloud of terrain, buildings, vegetation or other surfaces. LiDAR is used in topographic mapping, forestry, coastal surveys, archaeology and atmospheric research, from aircraft, satellites and ground-based instruments.
Updated 19 Oct 2026
Technology
Lithium-ion battery
A lithium-ion battery is a rechargeable electrochemical battery in which lithium ions move between electrodes during charging and discharging. Its combination of relatively high energy storage per unit mass and rechargeable operation has made it widely used in portable electronics, electric vehicles and some stationary energy-storage systems. The family includes several chemistries with different performance, material and safety characteristics.
Updated 15 Oct 2026
Technology
Lithium-ion battery recycling
Lithium-ion battery recycling recovers useful materials from manufacturing scrap and spent batteries so they can be processed for new products. Typical routes collect and sort batteries, make them safe for processing, and separate material streams; valuable cathode and anode components may be recovered from a powder known as black mass. Smelting, chemical leaching and direct recycling use different approaches and have different trade-offs. Recycling can reduce demand for newly mined materials and avoid unsafe disposal, but results depend on chemistry, collection, process design and energy sources.
Updated 28 Oct 2026
Technology
Magnetic recording
Magnetic recording stores information by creating patterns of magnetization in a medium and later detecting those patterns. The technique underlies technologies such as magnetic tape and hard disk drives, though their materials and reading methods differ.
Updated 7 Nov 2026
Technology
Merkle tree
A Merkle tree is a data structure in which cryptographic hashes link data items into a hierarchy. A hash at the root can commit to the contents of the entire tree, while a compact inclusion proof lets a verifier check one item using only the hashes along its path. Merkle trees are used in authenticated data structures and public append-only logs, including Certificate Transparency.
Updated 25 Oct 2026
Technology
Morse code
Morse code is a method of representing letters, numerals and some punctuation as sequences of short and long signals separated by timed intervals. Developed for electric telegraphy in the nineteenth century, it made it possible to send text using electrical pulses and later radio or other signals. The internationally standardized code is still used in some radiocommunication services, including amateur radio.
Updated 13 Oct 2026
Technology
Open-source software
Open-source software is software distributed under a licence that allows its source code to be studied, modified and redistributed under stated conditions. The category is defined by licensing terms, not simply by publishing code for others to see. Open-source projects use varied development and governance models, and the approach enables reuse and outside scrutiny without guaranteeing that software is secure, well-maintained or free of charge.
Updated 16 Oct 2026
Technology
Operating system
An operating system (OS) is system software that coordinates a computer’s hardware and applications. It allocates processor time, memory, storage and input/output resources, manages files and devices, and provides interfaces through which users and programs request services. Operating systems range from general-purpose desktop and mobile platforms to specialized embedded and real-time systems. Their designs balance resource use, responsiveness, compatibility, reliability and security.
Updated 19 Oct 2026
Technology
Optical fiber
An optical fiber is a thin, flexible waveguide that carries light through a transparent core surrounded by cladding. By guiding light with low signal loss, fiber supports high-capacity communications over short and long distances. Differences in core size and how light travels distinguish single-mode from multimode fiber, while precision in materials and construction affects transmission quality.
Updated 16 Oct 2026
Technology
Osmotic power
Osmotic power, also called salinity-gradient energy, seeks to generate electricity from the free energy released when waters of different salt concentrations mix. Two principal membrane approaches are pressure-retarded osmosis, which converts osmotic water flow into pressurized flow, and reverse electrodialysis, which converts selective ion transport into electrical current. Despite prototypes and research advances, membrane performance, fouling, pumping requirements, costs and ecological constraints have limited deployment.
Updated 27 Oct 2026
Technology
Perovskite Solar Cells
Perovskite solar cells are photovoltaic devices that use a metal-halide perovskite as their principal light-absorbing layer. Their thin-film form and strong light absorption have enabled rapid gains in laboratory efficiency, and they can be combined with silicon in tandem cells. Commercial deployment at scale remains under development, with stability, manufacturing, scale-up performance and validation posing important challenges.
Updated 7 Nov 2026
Technology
Printing press
A printing press transfers inked text or images to paper by applying pressure, often using reusable movable type. Printing developed through different methods in East Asia before the mechanized press became established in Europe in the fifteenth century. Johannes Gutenberg is associated with the European press that combined cast metal type with a mechanical printing process. By making repeated copies more practical, presses helped expand the circulation of books and ideas, while later mechanical innovations greatly increased production speed.
Updated 13 Oct 2026
Technology
QR code
A QR code (Quick Response Code) is a two-dimensional matrix barcode that represents data in a pattern of dark and light modules. Developed by DENSO WAVE in Japan for rapid, high-capacity identification in manufacturing, it can be read in different orientations and can remain readable after some damage through error correction. Its standardized format supports uses from product identification and logistics to mobile links and tickets, although a code's destination still needs to be trustworthy.
Updated 18 Oct 2026
Technology
Quantum computing
Quantum computing is a field of computing that uses quantum states to represent and process information. Its basic information units, qubits, can exhibit superposition and entanglement, while quantum operations use interference to shape measurement outcomes. Quantum computers may outperform classical machines on certain specialized tasks, but present devices remain error-prone and are not general replacements for ordinary computers.
Updated 21 Oct 2026
Technology
Quantum key distribution
Quantum key distribution (QKD) is a method for establishing shared cryptographic keys using quantum states, commonly photons, alongside classical communication. By testing for disturbances in transmitted quantum signals, participants can estimate whether the channel is secure enough to retain a key. QKD distributes key material rather than encrypting the message itself, and practical security also depends on authentication, hardware, implementation and network design.
Updated 6 Nov 2026
Technology
Robotics
Robotics is the field concerned with designing, building and operating machines that carry out physical tasks. Robots combine structures, actuators, sensors and control systems; some follow tightly defined programs, while others use perception and a degree of autonomy to move or act in changing environments. Artificial intelligence can support robotic perception or planning, but the fields are not identical. Robots are used in manufacturing, research, public safety and space exploration, where reliability and safe interaction with people are continuing engineering challenges.
Updated 14 Oct 2026
Technology
Roman concrete
Roman concrete, commonly called opus caementicium, was a building material used across the Roman world for structures ranging from harbours to monumental architecture. Its recipes varied, but often combined lime-based mortar, aggregate and volcanic ash. Modern analysis of samples has drawn attention to lime-rich inclusions and hot mixing: researchers propose that these features could help some Roman concrete repair small cracks through mineral reactions, although the ancient material was not a single uniform formula and the mechanism should not be treated as a universal explanation for every surviving structure.
Updated 22 Oct 2026
Technology
Scanning tunneling microscope
A scanning tunneling microscope (STM) maps a surface by measuring quantum-mechanical tunneling current between a sharp conductive tip and a nearby conducting sample. Because the current changes strongly with tip–sample separation and also reflects surface electronic states, an STM can resolve atomic-scale surface structure under suitable conditions.
Updated 31 Oct 2026
Technology
Semiconductors
Semiconductors are materials whose electrical conductivity can be controlled, making them useful for devices that guide, switch, amplify or convert electrical signals. Silicon is the most widely used semiconductor for integrated circuits, but the field also includes materials such as germanium, gallium arsenide, silicon carbide and gallium nitride. By shaping semiconductor crystals and combining many components on a chip, engineers create the processors, memories, sensors and power-control devices used throughout modern technology.
Updated 12 Oct 2026
Technology
Sewing machine
A sewing machine is a device that joins fabric or other materials with thread using mechanical action. Its development involved multiple inventors and designs, rather than a single uncontested moment of invention. Elias Howe’s 1846 U.S. patent described a practical lockstitch machine using an eye-pointed needle and shuttle; later patent disputes and manufacturing advances helped establish the industry. Sewing machines became important in both garment production and domestic sewing.
Updated 1 Nov 2026
Technology
Sodium-ion battery
A sodium-ion battery is a rechargeable electrochemical cell that stores and releases energy by moving sodium ions between its electrodes. Its operating principle resembles that of a lithium-ion battery, but it uses sodium-bearing materials. Sodium's abundance and the possibility of reducing reliance on certain constrained battery materials make the technology attractive, especially for stationary storage. Trade-offs in energy density, cost, lifetime and manufacturing readiness vary by chemistry and application, so sodium-ion cells are considered complementary to—not a universal replacement for—lithium-ion batteries.
Updated 27 Oct 2026
Technology
Solar cooker
A solar cooker is a device that uses sunlight as its energy source to heat or cook food. Common designs—box, panel and parabolic cookers—capture and concentrate solar radiation in different ways. Their performance depends on sunlight, weather, design and how they are operated, so they are generally used when conditions are suitable rather than as a universal replacement for other cooking methods.
Updated 1 Nov 2026
Technology
Solar energy
Solar energy is radiant energy from the Sun that people capture as electricity or heat. Photovoltaic cells convert light directly into electricity, while concentrating solar-thermal systems use mirrors to collect heat that can drive turbines or serve industrial processes. Solar output varies with sunlight, so storage and power-system planning can help match generation with demand; PV equipment also requires attention to end-of-life management.
Updated 15 Oct 2026
Technology
Steam engine
A steam engine converts heat into mechanical work by using expanding steam as a working fluid. Early practical engines pumped water from mines; later designs powered factory machinery, locomotives, and ships. Reciprocating piston engines helped drive industrialization, while steam turbines—different machines that use steam to spin blades—remain important in electricity generation.
Updated 18 Oct 2026
Technology
Sustainable aviation fuel
Sustainable aviation fuel (SAF) is aviation fuel made from non-petroleum feedstocks or other qualifying low-carbon sources and designed to replace part of conventional jet fuel. Depending on its feedstock and production route, its lifecycle greenhouse-gas emissions can be lower than those of fossil jet fuel, but the benefit must be assessed across production and use rather than inferred from the fuel's name. Approved SAF pathways are generally blended with conventional jet fuel and subject to fuel-quality and sustainability rules.
Updated 25 Oct 2026
Technology
Telephone
A telephone is a device and communications service that enables people to exchange speech across distance. A microphone converts sound into electrical signals, which a communications network transmits and routes; a receiver turns the arriving signal back into sound. Since nineteenth-century wired instruments, telephony has developed into large switched networks, automatic dialing, digital transmission and mobile services.
Updated 21 Oct 2026
Technology
Turtle excluder device
A turtle excluder device (TED) is a selective grid fitted inside a trawl net that lets shrimp and other small catch pass into the net's collection end while guiding larger animals, especially sea turtles, toward an escape opening. Developed through collaboration among fisheries scientists, managers and fishers, TEDs are used to reduce accidental capture and drowning of turtles in some shrimp-trawl fisheries. Their effectiveness depends on design, installation and operating conditions.
Updated 24 Oct 2026
Technology
Unified Payments Interface (UPI)
The Unified Payments Interface (UPI) is an Indian instant-payment system that connects participating banks and payment applications to enable interoperable transfers and merchant payments. Developed by the National Payments Corporation of India (NPCI), it was launched in 2016. UPI apps can link multiple permitted bank accounts and route payments using identifiers such as a UPI ID or QR code, while the system operates around the clock. Its expansion has made it a central part of India's retail digital-payment ecosystem.
Updated 31 Oct 2026
Technology
Virtual reality
Virtual reality (VR) is a computer-generated environment with which a person can interact, often through a head-mounted display and motion tracking. The technology can create a sense of presence—the feeling of being in a simulated place—but systems range from immersive headsets to projection-based simulations. VR is used in entertainment, design, education, health care and high-risk training, while access, physical comfort and cybersickness remain practical concerns.
Updated 17 Oct 2026
Technology
Water hammer
Water hammer is a transient pressure disturbance in a pipe caused by a rapid change in liquid flow. Sudden valve movements, pump starts or stops, and other abrupt changes can launch pressure waves that travel through the fluid and interact with the pipe. Depending on system design and operating conditions, these transients can produce noise, vibration, excessive pressure or low-pressure conditions.
Updated 28 Oct 2026