It is regrettable that the quantum length of an object is rarely if ever discussed, because it provides an ideal pedagogical paradigm for understanding how a physicist uses classical intuition to define quantum properties and how such quantum properties behave as one would expect in the classical limit. It also provides for a way to understand many-particle states, and leads to interesting quantum behavior that challenges our intuition about measurement. This exercise parallels the ways in which theories are developed, giving the student a concrete example of the thought process involved.

中文翻译：

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长度作为理解经典极限的范例

令人遗憾的是，很少讨论对象的量子长度，因为它提供了理想的教学范式，可以帮助物理学家理解经典的直觉来定义量子性质，以及这种量子性质在经典极限下的表现。它还提供了一种理解多粒子状态的方法，并导致有趣的量子行为，这挑战了我们对测量的直觉。这项练习与理论发展的方式平行，为学生提供了所涉及的思维过程的具体例子。