But the civilizations he was asking about would have existed many millions of years ago. Sitting there, seeing Earth’s vast evolutionary past telescope before my mind’s eye, I felt a kind of ...

The Silurians are a fictional race of intelligent, bipedal reptiles from the British science-fiction series "Doctor Who" that supposedly lived on Earth hundreds of millions of years ago.

Scientists put the Silurian hypothesis to the test, to see if humans were the first major civilization on Earth. Scientists questioned what traces an industrial civilization would leave behind.

Are we the first, though? Researchers from the University of Rochester and NASA have produced a paper that details how we might be able to tell if humans are the first civilization to arise on Earth.

In the grand sweep of Earth’s four-billion-year history, 300 years is barely a blink. And yet, that blink — our industrial era — has already reshaped the atmosphere, oceans, and sediments. If ...

I had certainly come into Gavin’s office prepared for eye rolls at the mention of “exo-civilizations.” But the civilizations he was asking about would have existed many millions of years ago. Sitting ...

Learn how the first civilization in Mesopotamia depended on tides and how it responded when faced with a major environmental ...