Terms starting with P
72 terms · page 3 of 3
Polar Coordinates
A 2D coordinate system specifying point location by radial distance r from the origin and angular displacement θ from a reference axis.
OpticsPolarization
The property of transverse electromagnetic waves specifying the geometric orientation of their electric field vector oscillations in space.
Condensed Matter & Materials PhysicsPolaron
A composite quasiparticle consisting of a conduction electron (or hole) bound together with its surrounding self-induced lattice…
Quantum & Atomic PhysicsPopulation Inversion
A non-equilibrium state of a quantum system where more atoms reside in a higher excited energy state than in lower energy states.
Biophysics & Medical PhysicsPositron Emission Tomography (PET Scan)
A 3D nuclear medicine imaging technique detecting pairs of 511 keV gamma photons emitted during positron annihilation to map metabolic…
Classical MechanicsPotential Energy
The stored energy an object possesses due to its relative position in a conservative force field or its structural deformation.
Classical MechanicsPower
The rate at which work is performed or energy is transferred per unit time.
Electromagnetism & ElectronicsPower Factor
The ratio of real power dissipated by an AC circuit to the apparent power delivered by the supply.
Electromagnetism & ElectronicsPoynting Vector
A vector representing the directional energy flux density (power per unit area) transported by an electromagnetic field.
Geophysics & Environmental PhysicsPrecession of the Equinoxes
The slow continuous conical rotation of Earth's rotational axis in space, taking ~25,800 years to complete one full cycle.
Foundations of PhysicsPrecision
The degree of agreement or repeatability among independent measurements of the same quantity taken under identical conditions.
OpticsPresbyopia
The age-related loss of accommodation power in the human eye caused by reduced elasticity of the crystalline lens.
Foundations of PhysicsPressure
The perpendicular force exerted per unit surface area over which that force is distributed.
Quantum & Atomic PhysicsPrincipal Quantum Number
The primary quantum number designating the main electron shell, overall orbital size, and principal energy level of an electron in an atom.
Thermodynamics & Statistical PhysicsPrinciple of Mixtures
The heat conservation principle stating that in an isolated system, heat lost by hotter components equals heat gained by cooler components…
Waves, Oscillations & AcousticsPrinciple of Superposition
The principle stating that when two or more linear waves overlap at a point, total resultant displacement equals vector sum of individual…
Quantum & Atomic PhysicsProbability Density
The probability per unit volume of finding a quantum particle at a specific spatial position at a given time.
Classical MechanicsProjectile Motion
The 2D motion of an object launched into a gravitational field under the sole influence of gravity (ignoring air resistance).
Astrophysics, Cosmology & RelativityProper Time
The physical time interval measured by a clock moving along a specific worldline through spacetime.
Biophysics & Medical PhysicsProtein Folding
The physical process by which a polypeptide chain folds spontaneously into a characteristic 3D functional native structure.
Biophysics & Medical PhysicsProton Therapy
An advanced form of external beam radiation therapy utilizing accelerated proton beams to destroy cancerous tumors.
Astrophysics, Cosmology & RelativityProtostar
An early evolutionary mass phase of a star formed by the gravitational contraction of an interstellar gas cloud before core hydrogen fusion…
Astrophysics, Cosmology & RelativityPulsar
A highly magnetized, rapidly rotating neutron star that emits focused beams of electromagnetic radiation from its magnetic poles.
Biophysics & Medical PhysicsPulse Oximetry
A non-invasive medical monitoring method measuring arterial blood oxygen saturation (SpO₂) using differential optical absorption of red and…