[Nowhere Man]

I often wonder about things like that if a technical civilization arose on Earth once or twice before ours. If this is the case, I wonder how their atomic weapons were constructed compared to ours plus they are high maintenance items. Would their U235 nukes resemble the Hiroshima gun bomb or if they used Pu239 (Plutionium) implosion weapons, would they use the same "soccer ball" implosion mechanism we do? I know the laws of physics were the same then as now, but I often wonder if they used the same ideas we do.

I often thought it would have been cool where the Apollo Astronauts would land on the Moon only to find that we've been there thousands of years before where they would look at each other and go "huh?"

[Old Student]

“I often thought it would have been cool where the Apollo Astronauts would land on the Moon only to find that we’ve been there thousands of years before where they would look at each other and go ‘huh?’”

Read James Hogan’s “Inherit the Stars” for a similar idea. Not Apollo astronauts, but the folks who continued exploring the Moon afterwards.... This is from Baen’s Free Library, Baen being one of the better publishers of science fiction, these days.

http://www.webscription.net/10.1125/Baen/0345301072/0345301072.htm

[Nikas777]

I often wonder about things like that if a technical civilization arose on Earth once or twice before ours.

The UNDERWORLD thesis of Hancock’s is that during near the end of the Ice Age there arose an advanced stone age coastal civilization - not advanced like they had cars or lasers but advances like the Egyptians and when the great melt happened this far flung coastal civilization/empire was drowned giving rise to the Atlantis myth and other flood myths with the survivors of the coastal flood moving inland to be among the less advanced humans of the inner continents who viewed the more advances coastal dwellers as gods or near gods. What survived are racial memories and some passed down knowledge turned to myth and legends but for the most part real evidence for this civilization is buried under the seas.

See review of his book here: http://www.freerepublic.com/focus/f-chat/2355928/posts