Uncharted underground

Physics Recent Work

Matt Covington didn’t sleep much the night before
his big swim. Who could blame him? For two days,
the wiry caver had, with the help of ropes and ladders,
been making his way down through J2, a deep
cave in the mountainous Mexican province of Oaxaca.
Marcin Gala, an experienced caver from Poland,
joined him on the descent, just as he had on multiple
previous adventures.
The entrance to J2 is dramatic: it’s an enormous
100m wide sinkhole, lined with stubborn plants and
surrounded by tall trees. A small hole – about as tall
as a person – leads from the bottom of the sinkhole
deeper into the cave. Cables and ladders lead to a
series of tight turns and drops. Because of the quick
descent, once a caver enters J2, the Sun virtually vanishes.
No-one knows how far down J2 goes.