80 relations: Absorbance, Absorption (electromagnetic radiation), Absorption cross section, Air pollution, Atomic physics, Azimuth, Barn (unit), Beer–Lambert law, Centimetre, Classical mechanics, Collision, Common logarithm, Coulomb's law, Cross section (geometry), Dirac delta function, Elasticity (physics), Electromagnetism, Elementary particle, Femtometre, Flow velocity, Fog, Gas, Geometrical optics, Grammatical modifier, Gravity, Impact parameter, International System of Units, Lens (optics), Light, Logarithm, Luminescence, Luminosity (scattering theory), Magnetism, Mean free path, Meteorology, Metric prefix, Micro-, Micrometre, Milli-, Momentum, Momentum transfer, Natural logarithm, Nephelometer, Neutron, Neutron cross section, Nuclear cross section, Nuclear physics, Number density, Partial wave analysis, Particle detector, ..., Particle physics, Path length, Permittivity, Picometre, Quantum mechanics, Radar cross-section, Radius, Ray (optics), Reaction rate, Reduced mass, Resonance (particle physics), Rutherford scattering, S-matrix, Scattering, Scattering amplitude, Scattering theory, Sigma, Sine, Solid angle, Sphere, Spherical coordinate system, Square metre, Stationary state, Steradian, Transmittance, Transversality (mathematics), Visibility, Wave function, Wavelength, X-ray. Expand index (30 more) » « Shrink index
In chemistry, absorbance or decadic absorbance is the common logarithm of the ratio of incident to transmitted radiant power through a material, and spectral absorbance or spectral decadic absorbance is the common logarithm of the ratio of incident to transmitted spectral radiant power through a material.
In physics, absorption of electromagnetic radiation is the way in which the energy of a photon is taken up by matter, typically the electrons of an atom.
Absorption cross section is a measure for the probability of an absorption process.
Air pollution occurs when harmful or excessive quantities of substances including gases, particulates, and biological molecules are introduced into Earth's atmosphere.
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus.
An azimuth (from the pl. form of the Arabic noun "السَّمْت" as-samt, meaning "the direction") is an angular measurement in a spherical coordinate system.
A barn (symbol: b) is a unit of area equal to 10−28 m2 (100 fm2).
The Beer–Lambert law, also known as Beer's law, the Lambert–Beer law, or the Beer–Lambert–Bouguer law relates the attenuation of light to the properties of the material through which the light is travelling.
A centimetre (international spelling as used by the International Bureau of Weights and Measures; symbol cm) or centimeter (American spelling) is a unit of length in the metric system, equal to one hundredth of a metre, centi being the SI prefix for a factor of.
Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars and galaxies.
A collision is an event in which two or more bodies exert forces on each other for a relatively short time.
In mathematics, the common logarithm is the logarithm with base 10.
Coulomb's law, or Coulomb's inverse-square law, is a law of physics for quantifying the amount of force with which stationary electrically charged particles repel or attract each other.
In geometry and science, a cross section is the non-empty intersection of a solid body in three-dimensional space with a plane, or the analog in higher-dimensional spaces.
In mathematics, the Dirac delta function (function) is a generalized function or distribution introduced by the physicist Paul Dirac.
In physics, elasticity (from Greek ἐλαστός "ductible") is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed.
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles.
In particle physics, an elementary particle or fundamental particle is a particle with no substructure, thus not composed of other particles.
The femtometre (American spelling femtometer, symbol fm derived from the Danish and Norwegian word femten, "fifteen"+Ancient Greek: μέτρον, metrοn, "unit of measurement") is an SI unit of length equal to 10−15 metres, which means a quadrillionth of one.
In continuum mechanics the macroscopic velocity, also flow velocity in fluid dynamics or drift velocity in electromagnetism, is a vector field used to mathematically describe the motion of a continuum.
Fog is a visible aerosol consisting of minute water droplets or ice crystals suspended in the air at or near the Earth's surface.
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
Geometrical optics, or ray optics, describes light propagation in terms of rays.
In grammar, a modifier is an optional element in phrase structure or clause structure.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
The impact parameter b is defined as the perpendicular distance between the path of a projectile and the center of a potential field U(r) created by an object that the projectile is approaching (see diagram).
The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.
A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
In mathematics, the logarithm is the inverse function to exponentiation.
Luminescence is emission of light by a substance not resulting from heat; it is thus a form of cold-body radiation.
In scattering theory and accelerator physics, luminosity (L) is the ratio of the number of events detected (N) in a certain time (t) to the interaction cross-section (&sigma): L.
Magnetism is a class of physical phenomena that are mediated by magnetic fields.
In physics, the mean free path is the average distance traveled by a moving particle (such as an atom, a molecule, a photon) between successive impacts (collisions), which modify its direction or energy or other particle properties.
Meteorology is a branch of the atmospheric sciences which includes atmospheric chemistry and atmospheric physics, with a major focus on weather forecasting.
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit.
Micro- (symbol µ) is a unit prefix in the metric system denoting a factor of 10−6 (one millionth).
The micrometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is an SI derived unit of length equaling (SI standard prefix "micro-".
Milli- (symbol m) is a unit prefix in the metric system denoting a factor of one thousandth (10−3).
In Newtonian mechanics, linear momentum, translational momentum, or simply momentum (pl. momenta) is the product of the mass and velocity of an object.
In particle physics, wave mechanics and optics, momentum transfer is the amount of momentum that one particle gives to another particle.
The natural logarithm of a number is its logarithm to the base of the mathematical constant ''e'', where e is an irrational and transcendental number approximately equal to.
A nephelometer is an instrument for measuring concentration of suspended particulates in a liquid or gas colloid.
In nuclear and particle physics, the concept of a neutron cross section is used to express the likelihood of interaction between an incident neutron and a target nucleus.
The nuclear cross section of a nucleus is used to characterize the probability that a nuclear reaction will occur.
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions.
In physics, astronomy, chemistry, biology and geography, number density (symbol: n or ρN) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volumetric number density, two-dimensional areal number density, or one-dimensional line number density.
Partial wave analysis, in the context of quantum mechanics, refers to a technique for solving scattering problems by decomposing each wave into its constituent angular momentum components and solving using boundary conditions.
In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionizing particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator.
Particle physics (also high energy physics) is the branch of physics that studies the nature of the particles that constitute matter and radiation.
Path length can mean one of several related concepts.
In electromagnetism, absolute permittivity, often simply called permittivity, usually denoted by the Greek letter ε (epsilon), is the measure of resistance that is encountered when forming an electric field in a particular medium.
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the metric system, equal to, or one trillionth of a metre, which is the SI base unit of length.
Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.
Radar cross-section (RCS) is a measure of how detectable an object is by radar.
In classical geometry, a radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.
In optics a ray is an idealized model of light, obtained by choosing a line that is perpendicular to the wavefronts of the actual light, and that points in the direction of energy flow.
The reaction rate or rate of reaction is the speed at which reactants are converted into products.
In physics, the reduced mass is the "effective" inertial mass appearing in the two-body problem of Newtonian mechanics.
In particle physics, a resonance is the peak located around a certain energy found in differential cross sections of scattering experiments.
Rutherford scattering is the elastic scattering of charged particles by the Coulomb interaction.
In physics, the S-matrix or scattering matrix relates the initial state and the final state of a physical system undergoing a scattering process.
Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass.
In quantum physics, the scattering amplitude is the probability amplitude of the outgoing spherical wave relative to the incoming plane wave in a stationary-state scattering process.
In mathematics and physics, scattering theory is a framework for studying and understanding the scattering of waves and particles.
Sigma (upper-case Σ, lower-case σ, lower-case in word-final position ς; σίγμα) is the eighteenth letter of the Greek alphabet.
In mathematics, the sine is a trigonometric function of an angle.
In geometry, a solid angle (symbol) is a measure of the amount of the field of view from some particular point that a given object covers.
A sphere (from Greek σφαῖρα — sphaira, "globe, ball") is a perfectly round geometrical object in three-dimensional space that is the surface of a completely round ball (viz., analogous to the circular objects in two dimensions, where a "circle" circumscribes its "disk").
In mathematics, a spherical coordinate system is a coordinate system for three-dimensional space where the position of a point is specified by three numbers: the radial distance of that point from a fixed origin, its polar angle measured from a fixed zenith direction, and the azimuth angle of its orthogonal projection on a reference plane that passes through the origin and is orthogonal to the zenith, measured from a fixed reference direction on that plane.
The square metre (International spelling as used by the International Bureau of Weights and Measures) or square meter (American spelling) is the SI derived unit of area, with symbol m2 (Unicode character). It is the area of a square whose sides measure exactly one metre.
A stationary state is a quantum state with all observables independent of time.
Transmittance of the surface of a material is its effectiveness in transmitting radiant energy.
In mathematics, transversality is a notion that describes how spaces can intersect; transversality can be seen as the "opposite" of tangency, and plays a role in general position.
In meteorology, visibility is a measure of the distance at which an object or light can be clearly discerned.
A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
X-rays make up X-radiation, a form of electromagnetic radiation.
Cross-section (physics), Differential Cross Section, Differential cross section, Differential cross-section, Particle cross section, Rate (particle physics), Scattering cross section, Scattering cross-section.