← All case files
View as graph →
CASE #H06N8U · 2 entities · 1 connections
The Hollow Earth Theory
A U.S. Army officer once got Congress to almost fund an expedition to the center of the Earth — because he believed we could walk inside it.
The idea that the Earth is hollow, or contains a vast inhabitable interior, was seriously proposed by scientists as early as the 17th century and championed by American officer John Cleves Symmes Jr. in the 1800s, who nearly secured government funding for a polar expedition to find the entrance. The theory was scientifically disproven by the mid-1700s but persists in fringe and conspiracy circles today.
⇄disputed
Quick facts
- →Astronomer Edmond Halley seriously proposed a version of Hollow Earth theory in 1692 to explain unusual compass readings.
- →John Cleves Symmes Jr. spent years lecturing across America in the 1820s trying to raise funding for a polar expedition to find the Earth's supposed opening.
- →The theory was definitively disproven by the 1774 Schiehallion experiment, which measured Earth's density and found it far too dense to be hollow.
- →The idea persists today mainly in conspiracy circles and as a premise for fiction, not as a scientifically viable claim.
Entities on file
🧑
John Cleves Symmes Jr. (person)
Former U.S. Army officer who spent over a decade publicly campaigning for the Hollow Earth theory in the 1820s.
→ publicly campaigned for → Hollow Earth theory✓documented
Hollow Earth theory (document)
Pseudoscientific theory that Earth is hollow or contains a habitable interior, disproven scientifically in 1774.
No outgoing connections on file.