Masked dancers writhe across the wreckage to emphasize the emotional toil. The maggots, starved for oxygen, writhe and jump in the bag, creating a "pitter-patter" sound. Onlookers watched the three men twist and writhe on ropes that were too long. Suddenly, Spike begins to writhe in pain as his chip fires without provocation. The Tait conjectures involve concepts in knot theory such as alternating knots, chirality, and writhe. Supercoiling can be represented mathematically by the sum of twist and writhe. The above example illustrates that twist and writhe are interconvertible. The writhe is not a knot invariant. They may writhe from side to side when alarmed, but only for short distances. An association with the verb "writhe" was the etymology favored by J. R. R. Tolkien. Wr, called "writhe", is the number of superhelical twists. This follows because a knot's mirror image has opposite writhe. "W" is the writhe and "T" is the twist of the coil. In knot theory, there are several competing notions of the quantity "writhe", or "Wr". Supercoiling is characterized by the linking number, twist and writhe.