Interaction

Interaction is a kind of action that occurs as two or more objects have an effect upon one another. The idea of a two-way effect is essential in the concept of interaction, as opposed to a one-way causal effect. A closely related term is interconnectivity, which deals with the interactions of interactions within systems: combinations of many simple interactions can lead to surprising emergent phenomena. Interaction has different tailored meanings in various sciences. Changes can also involve interaction.

Casual examples of interaction outside science include:

In physics, a fundamental interaction or fundamental force is a process by which elementary particles interact with each other. An interaction is often described as a physical field, and is mediated by the exchange of gauge bosons between particles. For example, the interaction of charged particles takes place through the mediation of electromagnetic fields, whereas beta decay occurs by means of the weak interaction. An interaction is fundamental when it cannot be described in terms of other interactions. There are four known fundamental interactions in Nature: The electromagnetic, strong, weak, and gravitational interactions. The weak and electromagnetic interactions are unified in electroweak theory, which is unified with the strong force in the standard model.

Interactions between atoms and molecules:

In molecular biology, the knowledge on gene/protein interaction among themselves and with their metabolites is referred to as molecular pathways.

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