Why is it so hard to drill off Earth?

Humans have been digging underground for millennia—on the Earth. It's where we extract some of our most valuable resources that have moved society forward. For example, there wouldn't have been a Bronze Age without tin ...

What is a sinkhole? A geotechnical engineer explains

Sinkholes are back in the news after a 13-year-old boy fell down a two meter deep hole in a waterlogged football field in Sydney over the weekend. The boy reportedly sank further into the hole every time he tried to push ...

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