Scalar field
A scalar field associates a single number (or scalar) to every point in space. Scalar fields are often used in physics, for instance to indicate the temperature distribution throughout space, or the air pressure.
The derivative of a scalar field results in a vector field called the gradient.
In quantum field theory a scalar field is caused by the exchange of spin 0 particles.
Other kinds of fields include:
- Vector fields, which associate a vector to every point in space. Some examples of vector fields include the electromagnetic field or the newtonian gravitational field.
- Tensor fields, which associate a tensor to every point in space. In general relativity, gravity is associated with a tensor field. In particular, with the riemann curvature tensor. In Kaluza-Klein_theory spacetime is extended to five dimensions and its riemann curvature tensor can be separated out into ordinary four-dimensional gravitation plus an extra set, which is equivalent to Maxwell's equations for the electromagnetic field, plus an extra scalar field known as the "dilaton".