By Matin Durrani in Puebla, Mexico

So it’s day five of the Physics World Mexican adventure and today we’ve been to the Benemérita Universidad Autónoma de Puebla (BUAP), which is one of the oldest universities in the country. After taking a peek at a new facility containing one of the most advanced supercomputers in Latin America, we headed over to the Institute of Physics, where we bumped into Felipe Pachecho Vázquez.

He’s into the physics of granular materials and showed us a lovely little experiment to study how craters form. Most of these geological features – like the massive Chicxulub crater in the Mexican state of Yucatán – are created when something big from outer space lands on the Earth. But craters can also be formed by the Earth literally disappearing from under your feet. Known as “cavity collapse”, Felipe mimics the process using nothing more than a bucket of sand, a balloon and a pin.

Take a look at the video to find out how he does it. But if you think it’s no more than a bit of fun, you’re wrong: Felipe has had a paper accepted by one of the world’s top journals. So sometimes the simplest experiments can be the most meaningful.