You might remember the sand-blanketed playground from your childhood where you used to play and jump all the time. Or the sand at the beach where you have built and destroyed many sand castles. But do you know what happens when you pump air underneath a pile of sand?
The effect is really common in several industries and is called fluidization. It happens when a constant flow of air is introduced from the bottom of a granular or powdered material. As the air travels through the material, it reduces friction between granules and as a result, makes sand behave more like a liquid while making objects float or sink in it.
The effect is pretty amazing, and don’t believe us, watch it yourself.