On Lady Elliot Island on the Great Barrier Reef, visitors sometimes see a third lighthouse at night, although only two exist. A Melbourne team led by psychologist Charles Kemp has explained the 'phantom lighthouse' as a perceptual illusion, reports Spektrum der Wissenschaft in German. Standing with your back to the real tower, the beam seems to rise from the horizon. In total darkness the brain lacks reference points, reads the fast-moving end of the beam as near and slow, and places its source close by.

Virtual reality reproduced the effect, and similar sightings were reported in Brittany in 1937. A neat case of how ghost stories can start in our own visual system.

Source: Manon Bischoff, Spektrum der Wissenschaft (German) (2026-11-12)
https://www.spektrum.de/news/optische-illusion-forscher-lueften-geheimnis-des-phantom-leuchtturms/2353904

Summarised by the FTI newsdesk.