BUBBLING UP Gas flowing up through a gently vibrating glass chamber can cause solid grains to simulate a well-known fluid behavior. Here, bubbles of less dense sand (blue) rise through a layer of denser sand (white).
Alex Penn/ETH Zurich
BUBBLING UP Gas flowing up through a gently vibrating glass chamber can cause solid grains to simulate a well-known fluid behavior. Here, bubbles of less dense sand (blue) rise through a layer of denser sand (white).
Alex Penn/ETH Zurich