40,000 years of human exploration of the earth

Humans have lived on Earth's surface for hundreds of thousands of yearsspecifically, in the crust. We probably know about humanity's journey to escape to the skies: building giant kites, hot air balloons, and finally the first airplane. But what about our story of penetrating the earth? How did humans finally manage to brave the heat and rocksoften digging thousands of kilometers deep to find their treasure? Enjoy the video!