Everything below, the purely subjective opinion of the author, is supported by the information found from the Internet.
It is generally accepted, and so historically, that the development of industry and the most important discoveries among science and technology fell on the last 200 years, at the same moment the question arises, what happened before that?
There are theories that there was a civilization on earth before us, which for some unknown reason disappeared somewhere, again there are a number of theories about this. Scientists believe there was a war over technological weapons that wiped out their inhabitants.
But still, there is some evidence of the existence of an ancient civilization. During the Cold War, traces similar to those left by a tank were accidentally discovered.
Scientists were immediately sent to the place of discovery, who conducted research and found that these are indeed traces, from the tracks of a very large technique, they are about 10,000 years old.
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Unknown mechanism found by archaeologists.
Today, almost all over the Earth, artifacts are scattered that impress with their manufacturability. For example, in India, a whole building is carved in stone, and at the same time, it is decorated with complex elements.
Scientists claim that such structures were created using bronze tools, but how can you drill holes in very durable granite with bronze tools?
If you look closely at the rocks and stones that have been processed, you will notice stripes. The stripes very much resemble traces from modern diamond circles, don't they?
There are a lot of canyons in America that resemble quarries where very large machines worked. Again, this is just theory and guesswork of people doing some research and trying to get to the truth.
Maybe scientists and the government are deliberately hiding information so that people do not worry, as the saying goes "the less you know, the better you sleep."