Snowflakes are like letters from the sky, each crystal a note describing the atmosphere as it falls to the ground. They float effortlessly, but their creation is one of nature’s most complicated ...

MOST pebbles are of irregular shape; for example, in the glacial beds of flint pebbles near my home in Essex, at the most two per cent have any symmetry, and the presumption is that the large majority ...

As most powder granules in the industry have irregular shapes, the question posed does not have a straightforward answer. Industry, as a rule, circumnavigates the problem by deciding a single size, or ...