New York | Heidelberg, 12 July 2017 Leonardo Da Vinci had already noticed it. There is a very peculiar dynamics of granular matter, such as dry sand or grains of wheat. When these granular particles are left on a vibrating solid surface, they are not only subject to random vibrations, they are also under the spell of solid friction forces, like the force a dry floor would exert on a brick in contact with that floor. In a study published in The European Physical Journal E, Prasenjit Das from the Jawaharlal Nehru University, India, and colleagues extended our understanding of this problem from the well-known, one-dimensional case to multiple dimensions.