In my prior posting, entitled “Ancient Astronauts and Contemporary Skepticism,” I challenged the skeptics (assuming they do not want to acknowledge that the Nazca Lines were made to be viewed by an ancient astronaut) to provide a credible explanation of those geoglyphs. I argued that the people of Nazca cannot be considered unique in human history and that the skeptics need to find parallels elsewhere. However, I imagine that, instead of trying to produce a mundane explanation of the Nazca Lines, the skeptics could simply argue that I have not proven the contrary case.
The basic facts of the Nazca desert are easy to comprehend. Those large geoglyphs cannot be grasped by humans from the ground; in most cases, the hills or mountains are too distant for anyone to even notice that they are there. The figures on the ground can only be recognized from the air. Since humans were unable to fly until relatively recent times, it is logical to consider extraterrestrials as a potential explanation. I have seen skeptics, in desperation, argue that the people of Nazca, in the sixth century, knew how to make air balloons, but I do not believe it for one second.
For...