This is precisely my questionDale said:In this context a "source" is a non zero divergence. Do you have a definition for the divergence of a scalar function?
A scalar field is a concept in physics that describes a distribution of scalar values (such as temperature, pressure, or density) in a given space.
The source of a scalar field can vary depending on the specific field being studied. However, in general, the source is often a physical object or phenomenon that causes the scalar values to change in a particular space.
Some common examples of scalar fields include electric potential, gravitational potential, temperature distribution, and atmospheric pressure.
A scalar field only has a magnitude value at each point in space, while a vector field has both magnitude and direction at each point. Additionally, scalar fields are described by scalar equations, whereas vector fields are described by vector equations.
Scalar fields are used in many different areas of scientific research, including physics, engineering, and mathematics. They are particularly useful in modeling and predicting physical phenomena, such as fluid flow, heat transfer, and electromagnetic fields.