billiard

Particles act like billiard balls or waves on water, depending how you probe them.

For example, something tiny like an electron can act like a particle–getting shot through space and colliding with other particles like billiard balls.

The story of commercial plastics began in the 1860s, when John Wesley Hyatt, seeking a substitute for the ivory popularly used in billiard balls, landed on a material later called celluloid.

His lordship retired shortly to his study, Hetton and Mr. Haggard betook themselves to the billiard-room.

When his lordship retired early, as was his custom, the other men adjourned once more to the billiard-room.

Longcluse had made up his mind promptly on the night of the billiard-match played in the Saloon Tavern.

The improvement has come at last, and these streets are now almost of a billiard-table smoothness.

Its water in a general way moves as does a billiard ball when it flies from one cushion to another.