> It would be really weird if a Silurian civilization randomly pumped out a bunch of radioactive iron and didn't do anything else. We never know any data befor

> It would be really weird if a Silurian civilization randomly pumped out a bunch of radioactive iron and didn't do anything else. We never know any data before interpreting it through theories. All observations are, as Popper put it, theory-laden, and hence fallible, as all our theories are. Deutsch, David. The Beginning of Infinity Probably the best evidence that Fe60 is not "Silurian" in origin is that it still arrives on Earth [0]. 0. https://webarchiv.typo3.tum.de/PH/gams/fileadmin/w00bjs/www/Master_Thesis_Dominik_Koll.pdf https://webarchiv.typo3.tum.de/PH/gams/fileadmin/w00bjs/www/... Addendum: The Silurian Theory is sometimes an interesting way to explore ideas. I don't think that a large pre-human "civilization" need take the same form as what we think of as human civilization. Even some large human civilizations like that of the Indus River Valley or Harappan culture are less understood because they left less in the way of stuff analogous to current times: "In sharp contrast to this civilisation's contemporaries, Mesopotamia and ancient Egypt, no large monumental structures were built. There is no conclusive evidence of palaces or temples." https://en.wikipedia.org/wiki/Indus_Valley_Civilisation https://en.wikipedia.org/wiki/Indus_Valley_Civilisation