Why visitors see a phantom lighthouse that doesn't exist at Lady Elliot Island
Researchers have solved the mystery of why visitors to Lady Elliot Island see a phantom lighthouse beam that isn't there.
At night on Lady Elliot Island in the southern Great Barrier Reef, visitors stand between the real lighthouse and the sea and turn to face the ocean. Visitors see a beam of light on the horizon, but no lighthouse is there.
The illusion has puzzled visitors for decades and even made it into the island's tourist guide. Researchers travelled to the island and recreated the phantom in virtual reality to understand what happens.
The answer: your brain combines what it expects to see with the limited visual clues available at night. The distant part of the real beam appears to move too slowly, so your brain interprets it as coming from the horizon instead of from behind you.
The illusion works at at least 70 metres away, much closer than earlier visitors reported.
- 70 metres
- Minimum distance for illusion
- 1873
- First lighthouse built
- 1995
- Lighthouse decommissioned
- 1937 off Brittany
- Earliest known report
Why it mattersThe phantom lighthouse shows how your brain works as a prediction machine, mixing expectations with sensory data to make sense of the world.
AustraliaThis Australian research reveals how human perception works and demonstrates why illusions happen to ordinary people in everyday conditions.
✓ Claims checked against the source. checked 3 h ago
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