In 2010 an application for a wind farm at Burton upon Stather in North Lincolnshire was turned down because of its potential effect on autistic twin boys.

BBC: Steven Robinson

With twin fiddles you get an interesting chorus effect when they are playing the same note at a different pitch.

WSJ: Son Volt Dials Up the Honky-Tonk

The floors of the twin towers lie stacked one on top of the other, the result of the "pancake effect" when the towers collapsed.

CNN: workers