What is "retrocausality"

n. (context physics English) Any of several hypothetical phenomena that reverse causality, allowing an effect to occur before its cause

Retrocausality (also called retro-causation, retro-chronal causation, backward causation, and similar terms) is any of several hypothetical phenomena or processes that reverse causality, allowing an effect to occur before its cause.

Retrocausality is primarily a thought experiment in philosophy of science based on elements of physics, addressing whether the future can affect the present and whether the present can affect the past. Philosophical considerations of time travel often address the same issues as retrocausality, as do treatments of the subject in fiction, although the two terms are not universally synonymous.

While some discussion of retrocausality is confined to fringe science or pseudoscience, a few physical theories with mainstream legitimacy have sometimes been interpreted as leading to retrocausality. This has been problematic in physics because the distinction between cause-and-effect is not made at the most fundamental level within the field of physics.