The discovery of a new physical process in manganese metal is reported. This process will also be present for all manganese‐containing materials in condensed matter. The process was discovered by applying our new technique of XR‐HERFD (extended‐range high‐energy‐resolution fluorescence detection), which was developed from the popular high‐resolution RIXS (resonant inelastic X‐ray scattering) and HERFD approaches. The acquired data are accurate to many hundreds of standard deviations beyond what is regarded as the criterion for `discovery'. Identification and characterization of many‐body processes can shed light on the X‐ray absorption fine‐structure spectra and inform the scientist on how to interpret them, hence leading to the ability to measure the dynamical nanostructures which are observable using the XR‐HERFD method. Although the many‐body reduction factor has been used universally in X‐ray absorption spectroscopy in analysis over the past 30 years (thousands of papers per year), this experimental result proves that many‐body effects are not representable by any constant reduction factor parameter. This paradigm change will provide the foundation for many future studies and X‐ray spectroscopy. A new physical process in manganese, present for manganese‐containing materials and materials science, has been discovered by applying our new technique – XR‐HERFD (extended‐range high‐energy‐resolution fluorescence detection) – developed from high‐resolution RIXS (resonant inelastic X‐ray scattering) and HERFD (high‐energy‐resolution fluorescence detection).