Validation
In rare cases, a claim is validated by mainstream science; i.e., it is proven that some artifact was created with a technology not previously thought to have existed in the ancient culture that built it. One piece that changed mainstream understanding of ancient technology is the Antikythera mechanism, a type of mechanical computer which has been fully validated as a real object from about 150–100 BCE. Before X-ray examination, its clockwork-like appearance (dating about 1,000 years before clocks were invented) was cited as evidence of alien visitation by fringe sources.
A partially validated example is the Maine penny, from the Goddard site in Blue Hill, Maine, United States. It is an 11th century Norse coin found in an American Indian shell midden. Over 20,000 objects were found over a 15-year period at the site. The sole non-Native artifact was the coin. Some argue it demonstrates Norse visits to North America unknown to archaeology; mainstream belief is that it was brought to the site from Labrador or Newfoundland by native trade.
Read more about this topic: Out-of-place Artifact