arkkisäteily
Arkkisäteily is a Finnish term that appears in discussions about radiation phenomena described as originating from ancient, primordial, or fundamental-energy sources. In mainstream physics the expression is not a formally defined or widely accepted category, and its meaning varies between writers. Some usages present arkkisäteily as a speculative form of radiation linked to deep time, primordial fields, or the underlying structure of matter, while others use the term more loosely as a metaphor for signals tied to historical or archival processes rather than to a distinct physical radiation type.
Etymologically the word is a Finnish compound, combining ark- or arkti- elements with säteily, meaning radiation.
In practice, arkkisäteily is encountered mainly in popular science writings, speculative discussions, or certain fringe theories
See also: radiation, cosmic background radiation, background radiation, pseudoscience, fringe science.