Dimensionspast
Dimensionspast is a conceptual framework used in speculative fiction and theoretical discussions to explore the idea of alternate realities or timelines that are no longer accessible or actively exist in their original form. It posits that at any given moment, there are potentially infinite dimensions branching off from the present, each representing a different possible outcome or state of affairs. Dimensionspast refers specifically to those dimensions that have, for whatever reason, ceased to be part of the continuously unfolding present.
The reasons for a dimension becoming "past" are varied and depend on the specific fictional or theoretical
In some narratives, remnants or echoes of dimensionspast might still be detectable or have subtle influences