The Archdruid Report: Which Way To Heaven?
I don’t know of a better example of the way the collective imagination of the modern world shifted gears when Sputnik I broke free of the atmosphere and opened the Space Age. Until then, the top of the atmosphere might as well have been a sheet of iron, as the Egyptians thought it was. (Their logic was impeccable: polished iron is blue, and so is the sky; iron is strong and heatproof, and the sky would need to be both to deal in order to support the boat named Millions of Years on which Ra the sun god does his daily commute; besides, the only iron they knew came from meteorites, which they sensibly interpreted as stray chunks of sky that had fallen to earth. Many of our theories about nature will likely seem much less reasonable from the perspective of the far future.)
http://thearchdruidreport.blogspot.se/2013/09/which-way-to-heaven.html