In 1910 young Loren Eiseley watched the passage of Halley’s Comet with his father. The boy who became a famous naturalist was never again to see the spectacle except in his imagination. That childhood event contributed to the profound sense of time and space that marks The Invisible Pyramid. This collection of essays, first published shortly after Americans landed on the moon, explores inner and outer space, the vastness of the cosmos, and the limits of what can be known. Bringing poetic insight to scientific discipline, Eiseley makes connections between civilizations past and present, multiple universes, humankind, and nature.