蹦极(Bungee Jumping)，也叫机索跳，白话叫笨猪跳，是近些年来新兴的一项非常刺激的户外休闲活动。跳跃者站在约40米以上（相当于10层楼）高度的桥梁、塔顶、高楼、吊车甚至热气球上，把一端固定的一根长长的橡皮条绑在踝关节处然后两臂伸开，双腿并拢，头朝下跳下去。

Bungee jumping (Bungee Jumping), also known as machine rope jump *, called "stupid pig jump", is a very exciting outdoor leisure activity in recent years. Jumpers stand on bridges, tower tops, tall buildings, cranes and even hot air balloons about 40 meters high, tie a long rubber band with one end fixed to the ankle joint, then stretch out their arms, legs together and jump head down.

绑在跳跃者踝部的橡皮条很长，足以使跳跃者在空中享受几秒钟的“自由落体”。当人体落到离地面一定距离时，橡皮绳被拉开、绷紧、阻止人体继续下落，当到达最低点时橡皮再次弹起，人被拉起，随后，又落下，这样反复多次直到橡皮绳的弹性消失为止，这就是蹦极的全过程。

The rubber band tied to the jumper's ankle is long enough to allow the jumper to enjoy a few seconds of "free fall" in the air. When the human body falls to a certain distance from the ground, the rubber rope is pulled open, tightened, and prevents the human body from continuing to fall. When it reaches the lowest point, the rubber bounces again, the human being is pulled up, and then falls again and again until the elasticity of the rubber rope disappears, this is the whole process of bungee jumping.