Quarks

And suddenly the earth is gone - the danger of the holes below us (2018x17)

Data emisji: Sie 07, 2018

Only apparently we are on safe ground. Because the ground below us is by no means as stable as it seems at first. It's crawling with cavities. The causes are manifold: natural holes, man-made holes or underground explosions leaving huge holes. How high is the risk of being swallowed by a hole in the ground? What are the causes? And what can we do about it?