Every so often, Dan Frost hears a dull thud and his office floor vibrates. It can only mean one thing: one of his experiments has exploded again. Making his way downstairs to his lab, he finds the shock is written on the faces of his colleagues still in the lab. From where they were working, it felt like a small bomb had exploded, and their pupils are still dilated with fear. “It sounds horrific,” he says apologetically. “But it’s not dangerous – everything is protected.”
The odd explosion is part of the job. A scientist at the Bayerisches Geoinstitut in Germany, Frost is attempting to mimic the conditions of the Earth’s lower mantle, thousands of kilometres below our feet. That involves crushing rocks to some of the highest pressures known to humankind; little wonder there are the odd mishaps. As part of this work, Frost has found some surprising ways to make diamonds – from carbon dioxide for instance. And peanut butter. Yes, peanut butter.
Compared to our enormous advances in space exploration, we still know precious little about the world lying beneath our feet. Elementary geology tells us that the Earth’s interior can be divided into rough layers: the core, and the lower and upper mantle, and the crust. But their exact composition is still a mystery – and that’s a major gap in our knowledge.