Is it possible that another civilization existed before us? That's the question posited by the Silurian Hypothesis.

This video challenges the traditional academic timeline of human civilization, exploring evidence that suggests humans may have developed advanced societies far earlier than 6000 BC. From the ...

There are over 7 billion people living on the earth right now. Tens of millions are born and die each year. Every single one of us leaves signs of our existence in the air, water, soil -- even space.