Marc Robert, a young ex NASA engineer, managed to make sand liquid.
He filmed the whole process of transformation. His kids liked this "sand jacuzzi" a lot.
Marc's discovery is based on fluidized beds. It is a complicated process.
As a result of his experiments sand started to behave like water, there were even bubbles and waves on its surface.
Marc admits that it took him many attempts and a lot of time to reach the desired effect.
Here is a video about how he did it - enjoy!