Topic: Sir Edmund Halley

Tim Swartz discusses the historical scientific interest in the hollow earth, citing 17th-century figures like Sir Edmund Halley and Athanasius Kircher. Halley proposed a model of the earth consisting of concentric spheres similar to Russian nesting dolls. The discussion notes that while modern geology uses seismic waves to map the interior, humanity has only physically drilled a few miles deep, leaving much of the planet's core a matter of speculation.