We are humming happily along with the music.

Jacob’s Ladder displays are sometimes found in science museums and centers. In demonstrations, an electric spark jumps between two parallel wires when electrons fed into one of the wires repel each other, heating up the surrounding air so the spark rises with the hot air before dying at the top of the wires.

Gareth Bale gave his side hope with a goal shortly afterwards but the real damage was done and Chelsea reasserted their authority to finish easy winners with further goals from Ramires, Frank Lampard and Florent Malouda.

The participants (rhetors) included ”raptivist" Sister Souljah, as well as some older, more traditional male leaders from the African-American community and one white, female sociologist.