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Making Artificial Earthquakes with a Four-Tonne Steel Ball

2018-02-12 12,013 261 375,577 YouTube

In Göttingen, Germany, there's a four-tonne steel ball that can be raised up a 14-metre tower -- and then dropped in less than two seconds, crashing back to earth. It makes tiny, artificial earthquakes: here's why. Thanks to all the team at Wiechert'sche Erdbebenwarte Göttingen! You can find out more about them here: Three things I had to cut out of this video, because they didn't quite fit into the story or because I couldn't film them: The reason the steel ball survived two world wars is because the university's records listed it by use as a "rock-ball", not by composition as a "steel ball" - so no-one melted it down for weaponry. The observatory team refill that pit every year to make the ground flat, and the ball just digs a hole again. The rock's just being compressed underneath. They joke that, somewhere in Australia, there's a slowly growing hill... And finally, the ground steams for a little while after the ball hits: it gets rather warm... Edited by Michelle Martin (@mrsmmartin) I'm at on Twitter at on Facebook at and on Snapchat and Instagram as tomscottgo