Technology glossary

Protected Leave

Time away from work that an eligible employee may take under law or binding policy while retaining specified protections, such as job restoration, continued benefits, or protection from retaliation. Eligibility, pay, duration, and notice requirements vary by jurisdiction and leave type.

Protein Reconstruction

The inference of a protein's likely sequence or structure from incomplete, damaged, or indirect evidence.

Proteomic Aging Clock

A computational model that estimates biological age or age-related risk from the concentrations of many proteins in blood or another biological sample. Different clocks may be trained to predict chronological age, mortality, or organ-specific outcomes, so their scores are not interchangeable and do not directly measure lifespan.

Proxy Network

A set of systems that receives network traffic and forwards it to another destination, placing one or more relay points between the original sender and the final service.

Pseudolite

A pseudolite is a ground-based transmitter that broadcasts navigation-like ranging signals, acting as a local analogue of a navigation satellite. Pseudolites can augment satellite positioning in controlled areas or where satellite visibility is limited.

Pseudorange

A pseudorange is the apparent distance between a GNSS satellite and receiver calculated from signal travel time. It is called 'pseudo' because receiver clock error and atmospheric effects are initially mixed into the measurement and must be solved or corrected.

Psychedelic-Assisted Therapy

A structured clinical approach in which a psychedelic substance is administered under professional supervision as part of a broader program that includes preparation, monitoring, and psychological support. Evidence, approval status, risks, and legal availability vary by substance and jurisdiction.

Public Interest Journalism

Reporting that helps the public understand matters affecting communities, government, safety, rights and democratic accountability.

Purpose-Built Autonomous Vehicle

A road vehicle designed from the outset for automated operation rather than adapted from a conventional driver-controlled model.

Pyrocumulonimbus Cloud(pyroCb)

A thunderstorm cloud generated by intense heat and rising air from a wildfire or volcanic eruption. It can produce lightning, strong winds and inject smoke high into the atmosphere.

Quantum Chromodynamics (QCD)

The physical theory that describes the strong nuclear force and how quarks and gluons interact to form protons, neutrons, and other particles.

Quantum Network

A network that distributes quantum states or entanglement between separated devices. It may support quantum communication, sensing or distributed computing, but requires specialized sources, channels, memories and detectors.

Quantum-Dot Light-Emitting Diode(QLED)

A light-emitting device that uses semiconductor nanocrystals called quantum dots to produce color when electrically or optically excited. Quantum dots can provide narrow, tunable emission spectra, supporting bright and color-accurate displays and lighting.

Quark

An elementary particle and a fundamental building block of matter; protons and neutrons are each made of three quarks bound together by gluons.

Quasar

An extremely luminous active galactic nucleus powered by matter falling onto a supermassive black hole. Quasars can outshine their host galaxies and are visible across vast cosmic distances, making them valuable probes of the early universe and intervening matter.

Quasi-Solid Electrolyte

An electrolyte with a largely solid or gel-like structure that still permits ions to move between battery electrodes. It aims to combine the conductivity and interfacial contact of liquids with improved leakage resistance, mechanical stability, or safety associated with solids.

Radial Glia

Neural progenitor cells that help organize the developing brain and produce many neurons and glial cells. Their elongated fibers also guide newly formed neurons toward their destinations.

Radiation-Hardened Computing

Computing systems engineered to continue operating in environments with ionizing radiation, such as space or nuclear facilities. Protection may combine specialized components, shielding, redundant circuits, and software that detects or corrects radiation-induced errors.

Radioisotope Thermoelectric Generator (RTG)

A device that converts the heat released by the natural radioactive decay of a material, such as plutonium-238, directly into electricity, with no moving parts. Spacecraft traveling far from the Sun, such as Voyager 1 and 2 and other outer-planet missions, rely on RTGs because solar panels become impractical at those distances. Output declines gradually each year as the radioactive fuel decays.

Raman Spectroscopy

An analytical technique that identifies molecules and materials by measuring how monochromatic light, usually from a laser, changes energy when scattered by molecular vibrations. It can provide a chemical fingerprint with little sample preparation and may be used microscopically.

Randomized Controlled Trial(RCT)

A study in which participants are assigned by chance to an intervention group or one or more comparison groups. Randomization helps balance known and unknown confounding factors, making differences in outcomes more credibly attributable to the intervention when the trial is well designed and conducted.

RAS Inhibitor

A drug designed to block signaling driven by RAS proteins or specific mutated forms such as KRAS. Because abnormal RAS signaling promotes growth in many cancers, inhibitors can slow selected tumors, but effectiveness depends on the exact mutation, cancer type, resistance mechanisms, and treatment combination.

Reaction Latency

Reaction latency is the elapsed time between detecting a relevant change or event and producing the corresponding system response. In robotics, it includes sensing, inference, communication, and actuation delays.

Real-Time Decision Support

A system that analyzes current or rapidly arriving data and presents timely information, predictions, or recommendations to help a person make a decision. It supports human judgment rather than necessarily making the final decision automatically.

Real-Time Kinematic Positioning(RTK)

Real-Time Kinematic positioning (RTK) uses carrier-phase satellite measurements plus corrections from a reference station or network to achieve centimetre-level positioning, widely used in surveying, construction, agriculture and autonomous machines.

Real-Time Rendering

The generation of visual frames quickly enough to respond interactively to user input or changing data. It is used in games, simulations, design tools, and extended reality, where each frame must typically be produced within milliseconds.

Real-World Fuel Consumption

The amount of fuel a vehicle uses under actual driving conditions rather than in a standardized laboratory test. It varies with traffic, speed, weather, load, driving style, route, maintenance, and, for plug-in hybrids, how often the vehicle is charged.

Reasoning Model

A type of AI model designed to work through a problem step by step before producing a final answer, rather than generating an instant response.

Rebound Effect

A market or behavioral response in which an efficiency improvement lowers the cost of a service and encourages greater use, offsetting some or all of the expected resource or emissions saving.

Receiver Autonomous Integrity Monitoring(RAIM)

Receiver Autonomous Integrity Monitoring (RAIM) is a technique in which a GNSS receiver uses redundant satellite measurements to check whether its navigation solution is internally consistent and to detect certain faulty measurements.