Re:Was there a civilization on Earth before humans?
by i_am_nomad on Saturday April 14, 2018 @11:09AM
(#16837624)
Yes, absolutely. The article is borderline clickbait. If there were a technological civilization on Earth in the past, we would have detected it by now. Concentrations of radioisotopes, industrial ceramics, signs of large excavations in the fossil record... those are just a few.
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Re:Was there a civilization on Earth before humans?
by thaumaturgy on Saturday April 14, 2018 @11:49AM
(#16837812)
Radioisotopes decay; which isotopes are you thinking of that have half-lives of millions of years and would be found in detectable quantities?
(I was going to raise the same point, thinking of low-background steel and the effects of nuclear testing on our atmosphere, but after some more reading it appears that most of those isotopes decay over shorter periods or weren't sufficiently elevated to be discernible from the background, if it were being examined in the far future.)
Re:Was there a civilization on Earth before humans?
by garmaine on Wednesday April 25, 2018 @11:46AM
(#16922629)
Radioisotopes decay, but it is the ratio that is important. We know, for example, that a natural (we assume?) nuclear reactor occurred in Africa 1.8bn years ago due the different isotopic concentration of uranium deposits from that era.