frádráttar

Frádráttar is the Icelandic term for repulsion, the force that pushes two bodies or systems away from one another. In physics it is the counterpart to attraTION, which describes attraction. Repulsive forces occur in several fundamental interactions, most notably in electromagnetism, and in certain theoretical or specialized contexts in particle physics and cosmology. By contrast, gravity in everyday experience acts as an attractive force.

In electromagnetism, repulsion is most familiar from electric charges: like charges repel, while opposite charges attract. Coulomb’s law quantitatively describes this behavior, with the force between two charges increasing as they come closer and having the same direction as the line joining them when the charges have the same sign. Magnetic repulsion is another example, where two magnets with like poles facing each other push apart.

Repulsive forces have practical applications and consequences. Magnetic levitation (maglev) systems exploit repulsive interactions to reduce friction and support moving vehicles. In particle accelerators, repulsive electric forces between charged particle beams must be carefully managed to maintain beam stability and focus.

In classical gravity, repulsion is not observed; the gravitational interaction is always attractive between masses. Some speculative theories in advanced physics discuss ideas of repulsive gravity or dark energy phenomena, but these are not part of the standard description of repulsion in everyday physics.

See also: attraction, Coulomb’s law, magnetic force, gravitational force.