These grains can be solid, liquid or dust

(PhysOrg.com) -- Take a walk along the beach and you might marvel at any number of things: the cresting waves, the occasional scuttling crab, the shells and odd shapes of driftwood that wash ashore.

Hong Kong air pollution hits record levels

Hong Kong's air pollution soared to record levels Monday, the Environmental Protection Department said, warning that a toxic stew enveloping the city was a danger to the public.

Sandstorms blanket Beijing in yellow dust

Beijingers woke up Saturday to find the Chinese capital blanketed in yellow dust, as a sandstorm caused by a severe drought in the north and in Mongolia swept into the city.