On October 24th, 2012, the Eindhoven Multiscale Institute was formally opened by performing this multiscale experiment. The three pairs of hands are those of TU/e rector Hans van Duijn, the first EMI director Harald van Brummelen, and ICMS scientific director Bert Meijer.
Granular matter is special in many ways. This experiment shows one of them, how granular matter can be both solid and fluid, depending on the circumstances. The embedded letters have lower mass density than the surrounding particles, and if the experiment were performed in a fluid instead of granular matter, then the letters would rise to the surface. In granular matter at rest, however, they stay permanently hidden: the granules behave like a solid. Upon shaking, however, the granules start behaving like a fluid, and the lighter letters can float to the surface.
The multiscale nature of this experiment lies in the relation between the nature of this granular 'material' at smaller scales, and its behaviour at larger scales. At the scale of millimeters this matter is made of particles; at the scale of the letters the matter behaves either like a solid or a fluid. The connection between these two scales is a typical topic of research in Multiscale Science.
More information: tue.nl/en/research/research-institutes/top-research-groups/eindhoven-multiscale-institute/