A stroll on the beach can mean sinking your toes into smooth sand or walking firm-footed on a surface that appears almost solid. While both properties are commonplace, exactly what it is that makes ...

When we take a stroll on the beach, we walk on the sand without any trouble. The sand appears solid and is difficult to compress. When we put the same sand grains in an hourglass, they behave very ...

The hybrid behaviour of sand and foams has fascinated physicists for decades, and lies at the heart of Liu and Nagel's jamming diagram 2 (see Fig. 1a of the paper 1). The idea behind this diagram is ...