42,772 articles
Public awareness of science
Public awareness of science, also called public understanding of science, is how well the public knows, understands, trusts, and engages with science, tracked through large opinion surveys.
Public opinion on climate change
Public opinion on climate change, the measured beliefs, risk perceptions, and policy preferences gathered through repeated surveys, shows large majorities worldwide accept climate change and want stronger government action.
Puck
Puck (S/1985 U1, Uranus XV) is the largest small inner moon of Uranus, about 150 km across, discovered December 30, 1985 by Voyager 2, orbiting between the epsilon ring and Miranda, named for Shakespeare's sprite.
PUEO (balloon experiment)
PUEO, the Payload for Ultrahigh Energy Observations, is a NASA balloon experiment that flew over Antarctica in 2025 to detect ultra-high-energy neutrinos as the successor to ANITA.
Puerarin
Puerarin, also known as kakonein or daidzein-8-C-glucoside, is a major bioactive isoflavone of the kudzu root Pueraria lobata, whose puerarin injection has been used in China since the 1990s for cardiovascular conditions.
Puiseux series
A Puiseux series is a power series in fractional powers of a variable that expresses the local behavior of algebraic functions; the method goes back to Newton.
Pull-apart basin
A pull-apart basin is a structural depression formed by localized crustal extension at a releasing bend or stepover in a strike-slip fault system, named in 1966, with the Dead Sea basin among the largest.
Pullback (category theory)
A pullback, also called the fibered product, is the limit in category theory of two morphisms with a common codomain; in sets it is the set of pairs (a, b) with f(a) = g(b).
Pullulan
Pullulan is a linear, water-soluble polysaccharide produced by fermenting the fungus Aureobasidium pullulans, used in edible films, drug capsules, food packaging, and Listerine oral care strips.
Pulsar
A pulsar is a rapidly rotating neutron star whose beams of radiation sweep past Earth as highly regular pulses, discovered by Jocelyn Bell Burnell in 1967.
Pulsar clock
A pulsar clock is a timekeeping reference that uses the regular pulses of rotating neutron stars as its tick; millisecond pulsars rival the stability of the best atomic clocks.
Pulsar magnetosphere particle acceleration
Pulsar magnetosphere particle acceleration is the process by which a rotating neutron star converts spin-down power into energetic electrons and positrons that radiate radio, X-ray, and gamma-ray emission.
Pulsar planet
A pulsar planet is a planet orbiting a pulsar, a rapidly rotating neutron star. The first confirmed extrasolar planets were pulsar planets, announced in 1992 around PSR B1257+12.
Pulsar timing
Pulsar timing is an observational astronomy method that measures the arrival times of radio pulses from pulsars, probing neutron star structure and testing general relativity.
Pulsar timing array
A pulsar timing array is a set of millisecond pulsars whose precisely measured pulse times act as a galaxy-scale detector for nanohertz gravitational waves, which interferometers like LIGO cannot reach.
Pulsar wind nebula
A pulsar wind nebula (PWN) is a cloud of relativistic particles around a pulsar, powered by its wind and shining in X-rays and gamma rays; the Crab Nebula is the best-known example.
Pulsating white dwarf
A pulsating white dwarf is a white dwarf star whose brightness varies periodically through gravity-mode oscillations, first seen in 1968 and used in asteroseismology to probe stellar interiors.
Pulsational pair-instability supernova
A pulsational pair-instability supernova is a series of violent pulses and supernova-like mass ejections in very massive stars, distinct from a pair-instability supernova and ending in black hole collapse.
Pulse radiolysis
Pulse radiolysis is a time-resolved spectroscopy technique in which short pulses of high-energy electrons generate reactive intermediates in a sample, followed from femtoseconds to nanoseconds.
Pulse sequence
A pulse sequence in NMR spectroscopy is a programmed recipe of radiofrequency pulses, delays, and magnetic-field gradients that manipulates nuclear spins and determines the recorded signal.
Pulse voltammetry
Pulse voltammetry is a family of electroanalytical techniques, including DPV, NPV, and SWV, that applies potential pulses to a working electrode to detect and quantify electroactive species.
Pulse-code modulation
Pulse-code modulation (PCM) is a method of representing analog audio as a digital bitstream by sampling and quantizing it, used on compact discs and in digital telephony.
Pulsed amperometric detection
Pulsed amperometric detection (PAD) is an electrochemical detection technique in which repeating electrode potentials detect analytes while cleaning the electrode, best known in HPAEC-PAD carbohydrate analysis.
Pulsed electrochemical CO2 reduction
Pulsed electrochemical CO2 reduction is a mode of CO2 electrolysis that alternates the cathode potential between reducing and less reducing values to steer product selectivity.
Pulsed electrolysis
Pulsed electrolysis is an electrochemical method applying time-varying current or voltage waveforms instead of a constant current or potential, used to control reaction selectivity, catalyst state, and product formation.
Pulsed electron paramagnetic resonance
Pulsed electron paramagnetic resonance (pulsed EPR) is a spectroscopic technique that excites electron spins with short, high-power microwave pulses and Fourier transforms the emitted signal to obtain the spectrum.
Pulsed electron spin resonance spectroscopy
Pulsed electron spin resonance spectroscopy, or pulsed EPR, applies short, high-power microwave pulses to unpaired electron spins and records the resulting echo, measuring relaxation times, hyperfine couplings, and spin–spin distances.
Pulsed field gradient
A pulsed field gradient (PFG), or gradient NMR, is a short, strong magnetic field gradient applied during an NMR sequence to encode spin position as a phase shift.
Pulsed gradient spin echo
Pulsed gradient spin echo (PGSE) is a nuclear magnetic resonance technique for measuring molecular diffusion, introduced by Stejskal and Tanner in 1965 and widely used in diffusion MRI.
Pulsed-field gradient NMR
Pulsed-field gradient NMR, also called pulsed gradient spin-echo (PGSE) NMR, is an NMR technique that measures molecular self-diffusion, introduced by Stejskal and Tanner in 1965.