Point particle

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Point particle

A point particle (or point-like particle, often spelled pointlike particle) is an idealized object heavily used in physics

Physics

Physics is the natural science which examines basic concepts such as energy, force, and spacetime and all that derives from these, such as mass, charge, matter and its Motion ....
. Its defining feature is that it lacks spatial

Dimension

In mathematics, the dimension of a space is roughly defined as the minimum number of coordinates needed to specify every point within it. For example: a point on the unit circle in the plane can be specified by two Cartesian coordinates but one can make do with a single coordinate , so the circle is 1-dimensional even though it exists in...
extension

Extension

Extension may refer to:* A List of cheerleading stunts* The building of community capacity by outsiders, for instance agricultural extension* Extension , relating to the pulling apart of the Earth's crust and lithosphere...
: being zero-dimensional, it does not take up space. A point particle is an appropriate representation of any object whose size, shape, and structure is irrelevant in a given context. For example, from far enough away, an object of any shape will look and behave as a point-like object.

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Encyclopedia

A point particle (or point-like particle, often spelled pointlike particle) is an idealized object heavily used in physics

Physics

Dimension

Extension

Point mass

Point mass is an idealistic term used to describe either matter which is infinitely small, or an object which can be thought of as infinitely small....
es and point charge

Point charge

A point charge is an idealized model of a particle which has an electric charge. A point charge is an electric charge at a Point with no dimensions....
s, point particles whose only attributes are their mass

Mass

In physical science, mass refers to the degree of acceleration a body acquires when subject to a force: bodies with greater mass are accelerated less by the same force....
and charge

Charge

Charge or charged may refer to:...
respectively.

Sometimes due to specific combinations of properties extended objects behave as point-like even in their immediate vicinity. For example, spherical objects interacting in 3-dimensional space whose interactions are described by the inverse square law behave in such a way as if all their matter were concentrated in their geometric centers. In Newtonian gravitation and classical electromagnetism

Electromagnetism

Electromagnetism is the physics of the electromagnetic field, a field which exerts a force on Elementary particles with the property of electric charge and which is reciprocally affected by the presence and motion of such particles....
, for example, the respective fields

Field (physics)

In physics, a field is a physical quantity associated to each point of spacetime. A field can be classified as a scalar field, a vector field, or a tensor field, according to whether the value of the field at each point is a scalar , a vector , or, more generally, a tensor, respectively....
outside of a spherical object are identical to those of a point particle of equal charge/mass located at the center of the sphere.

In particle physics

Particle physics

Particle physics is a branch of physics that studies the elementary particle constituents of matter and radiation, and the interactions between them....
, "point particle" is synonymous with "elementary particle

Elementary particle

In particle physics, an elementary particle or fundamental particle is a wiktionary:particle not known to have substructure; that is, it is not known to be made up of smaller particles....
", which is defined as a particle without structure or, equivalently, as a particle which is not made up from component parts. According to the Standard Model

Standard Model

The Standard Model of particle physics is a theory of three of the four known fundamental interactions and the elementary particles that take part in these interactions....
of fundamental particles and forces, quark

Quark

Quarks are a type of elementary particle and major constituents of matter. They are the only particles in the Standard Model to experience all four fundamental interaction, which are also known as fundamental interactions....
s, lepton

Lepton

Leptons are a family of elementary particles, alongside quarks and gauge bosons . Like quarks, leptons are fermions and are subject to the electromagnetic force, the gravitational force, and weak interaction....
s and the (non-composite) vector boson

Vector boson

In particle physics, a vector boson is a boson with the spin quantum number equal to 1.The vector bosons considered to be elementary particles are the gauge bosons, the force carriers of fundamental interactions: the photon of electromagnetism, the W and Z bosons of the weak interaction, and the gluon of the strong interaction....
s are point particles in this sense. There is no experimental evidence for any of the elementary particles having spatial extent, and so they are usually considered to be point particles in the more general sense too (at least to the limited extent that the concept of a "particle" is meaningful in quantum field theory

Quantum field theory

Quantum field theory or QFT provides a theoretical framework for constructing quantum mechanics models of systems classically described by field or of Many-body problem....
).