In Goethe's ballad "Erlkönig," immortalized in Schubert's fevered 1815 setting, a dying boy riding through the night sees a spectral king beckoning from the darkness. His father calms him: "Mein Sohn, es ist ein Nebelstreif"—my son, it is only a wisp of fog. In the poem, the father's reassuranc...
Source: [Phys.org](https://phys.org/news/2026-08-mirror-world-particles-wisps-fog.html)