Relation to and comparison with other physical fields

Relation to and comparison with other physical fields

Main article: Fundamental forces

This section requires expansion.

Being one of the four fundamental forces of nature, it is useful to compare the electromagnetic field with the gravitational, strong and weak fields. The word 'force' is sometimes replaced by 'interaction' because the fundamental forces operate by exchanging what are now known to be gauge bosons.

Electromagnetic and gravitational fields

Sources of electromagnetic fields consist of two types of charge – positive and negative. This contrasts with the sources of the gravitational field, which are masses. Masses are sometimes described as gravitational charges, the important feature of them being that there is only one type (no negative masses), or, in more colloquial terms, 'gravity is always attractive'.
The relative strengths and ranges of the four interactions and other information are tabulated below:

Theory	Interaction	mediator	Relative Magnitude	Behavior	Range
Chromodynamics	Strong interaction	gluon	1038	1	10−15 m
Electrodynamics	Electromagnetic interaction	photon	1036	1/r2	infinite
Flavordynamics	Weak interaction	W and Z bosons	1025	1/r5 to 1/r7	10−16 m
Geometrodynamics	Gravitation	graviton	100	1/r2	infinite