Pablo and his students want to save the world – part two

2.1. What's in the box?“Well” the student explained, “this is for people stranded in the desert. It gives them drink-ing water. All they must do is to urinate in this bottle at the top and in a few minutes out of the spout at the side water will flow. And it is clean fresh water.” ...

A Critical Thinker’s Challenge

DisasterIn June of 1995 the roof of a five-storey department store, the Sampoong Department Store, in Seoul, Korea, collapsed, falling through all five floors in less than 20 seconds and killing over 500 shoppers and employees.Within a week the authorities had ascertained what caused the roof to collapse: an air conditioning unit weighing four times ...