World full of valves: Abrasion

In our video "World without valves", we demonstrated why our everyday world would look different without valves. In the second video, our professor is now travelling in the desert, and he is tackling the subject of "abrasion". But what actually is abrasion…, and what does it have to do with valves and piping? And with us? A lot of fun packed into just 1 minute and 35 seconds.