Basic facts of electromagnetism

Abstract

In giving an account of the behaviour of the natural world, physics has to recognise the existence of only three or four qualitatively different fundamental forces. Electromagnetism is concerned with the general properties of one of these forces. It has an importance which is not confined solely to its more obvious everyday manifestations in such things as telecommunications and electrical power systems. The structures and properties of the atoms and molecules that make up the natural world are also determined by the nature of this electromagnetic force. Electromagnetism is therefore the basis of any fundamental account of the richly varied natural phenomena that are dependent on these atomic and molecular properties. In this realm the other forces of physics are relatively insignificant. Gravitation is only important where objects of astronomical size are involved and nuclear forces are of too short a range to be effective on an atomic or larger scale. In fundamental terms therefore, electromagnetism accounts for the greater part of physics and essentially all of some other subject areas.