AT EARTH'S CORE.

The article explores the evolution of the Hollow-Earth Theory, beginning with Edmond Halley's 1691 hypothesis that the Earth is hollow and contains habitable spheres. Halley's ideas, initially grounded in scientific inquiry regarding magnetic anomalies, inspired later proponents like John Cleves Symmes Jr., who in 1818 proposed that the Earth has large openings at the poles leading to these inner worlds. The theory gained traction in literature and popular culture, particularly in the 19th and 20th centuries, with works that blended fiction and speculative science, including Edgar Rice Burroughs' "Pellucidar" series and the "Shaver Mystery" stories. Over time, the Hollow-Earth concept transitioned from a potential site for exploration and colonization to a realm associated with danger and conspiracy, reflecting changing societal fears and desires. [Extracted from the article]