Tightrope walking

Tightrope walking, also called funambulism, is the skill of walking along a thin wire or rope. It has a long tradition in various countries and is commonly associated with the circus. Other skills similar to tightrope walking include slack rope walking and slacklining.
Tightwire is the skill of maintaining balance while walking along a tensioned wire between two points. It can be done either using a balancing tool (umbrella, fan, balance pole, etc.) or "freehand", using only one's body to maintain balance. Typically, tightwire performances either include dance or object manipulation. Object manipulation acts include a variety of props in their acts, such as clubs, rings, hats, or canes. Tightwire performers have even used wheelbarrows with passengers, ladders, and animals in their act. The technique to maintain balance is to keep the performer's centre of mass above their support point—usually their feet.
Highwire is a form of tightwire walking but performed at much greater height. Although there is no official height when tightwire becomes highwire, generally a wire over 20 feet (6 m) high are regarded as a highwire act.
Skywalk is a form of highwire which is performed at great heights and length. A skywalk is performed outdoors between tall buildings, gorges, across waterfalls or other natural and man-made structures.
If the "lay" of the rope (the orientation of the constituent strands, the "twist" of a rope) is in one direction, the rope can twist on itself as it stretches and relaxes. Underfoot, this could be hazardous to disastrous in a tightrope. One solution is for the rope core to be made of steel cable, laid in the opposite direction to the outer layers, so that twisting forces balance each other out.
Acrobats maintain their balance by positioning their centre of mass directly over their base of support, i.e. shifting most of their weight over their legs, arms, or whatever part of their body they are using to hold them up. When they are on the ground with their feet side by side, the base of support is wide in the lateral direction but narrow in the sagittal (back-to-front) direction. In the case of highwire-walkers, their feet are parallel with each other, one foot positioned in front of the other while on the wire. Therefore, a tightwire walker's sway is side to side, their lateral support having been drastically reduced. In both cases, whether side by side or parallel, the ankle is the pivot point.
A wire-walker may use a pole for balance or may stretch out their arms perpendicular to their trunk in the manner of a pole. This technique provides several advantages. It distributes mass away from the pivot point, thereby increasing the moment of inertia. This reduces angular acceleration, so a greater torque is required to rotate the performer over the wire. The result is less tipping. In addition, the performer can also correct sway by rotating the pole. This will create an equal and opposite torque on the body.
Tightwire-walkers typically perform in very thin and flexible, leather-soled slippers with a full-length suede or leather sole to protect the feet from abrasions and bruises, while still allowing the foot to curve around the wire. Though very infrequent in performance, amateur, hobbyist, or inexperienced funambulists will often walk barefoot so that the wire can be grasped between the big and second toe. This is more often done when using a rope, as the softer and silkier fibres are less taxing on the bare foot than the harder and more abrasive braided wire.
The word funambulism, the phrase walking a tightrope, and associated variants also occur in metaphorical contexts not referring to any actual acrobatic acts. For instance, politicians are said to "walk a tightrope" when trying to balance two opposing views with little room for compromise. The idea can also appear in satirical or acidic contexts. Nicholas Taleb uses the concept in his book The Black Swan: "You get respect for doing funambulism or spectator sports [...]." Taleb is criticising scientists who prefer popularism to vigorous research and those who walk a fixed and narrow path rather than explore a large field of empirical study.