Chapter32 Relativity 固有长度L o (proper length 物体相对静止时所测得 的长度. The length of the object- or distance between two points whose positions are measured at the same time-as determined by observers at rest with respect to The Length of an object is measured to be shorter when it is moving relative to the observer than when it is at rest 结论:固有长度最长。 运动的棒长度收缩。固有长度L0 (proper length) ：物体相对静止时所测得 的长度 . The length of the object-or distance between two points whose positions are measured at the same time-as determined by observers at rest with respect to it. The Length of an object is measured to be shorter when it is moving relative to the observer than when it is at rest