Granular material physics of granular matter and whose book "The Physics of Blown Sand and Desert Dunes" remains an important reference to this day. According to material scientist Patrick Richard, "Granular materials are ubiquitous in nature and are the second-most manipulated material in industry (the first one is water)". In some sense, granular materials do not constitute a single phase of matter but have characteristics reminiscent of solids, liquids, or gases depending on the average energy per grain. However, in each of these states granular materials also exhibit properties which are unique. Granular materials also exhibit a wide range of pattern forming
Granular convection similar density, such as muesli mix. Under experimental conditions, granular convection of variously sized particles has been observed forming convection cells similar to fluid motion. The convection of granular flows is becoming a well-understood phenomenon. It may be counterintuitive to find that the largest and (presumably) heaviest particles rise to the top, but several explanations are possible: The phenomenon is related to Parrondo's paradox in as much as the Brazil nuts move to the top of the mixed nuts against the gravitational gradient when subjected to random shaking. Granular convection has been probed by the use of MRI where convection