So the Joule free expansion involves opening this valve and asking what happens when this gas moves into the other bulb or distributes between the two.

焦耳自由膨胀就是,打开阀门后的过程,气体从一个腔跑到另一个腔,并在它们之间平均分配。

麻省理工公开课 - 热力学与动力学课程节选

The answer is I can't. OK, in the simple case of integers I can, but in the case of something more complex like faces or fingerprints or passwords for that matter, it's hard to design a hash function that has completely even distribution, meaning that it takes any input into exactly one output spot.

答案是我不能，好吧,在简单的整数的例子中,我可以做到，但是在一些更复杂的场景中,比如面部，指纹，密码相关的问题中，很难设计一个哈希函数具备完全平均的分配,也就是说，做到对任一输入，可以准确地得到相应的唯一输出,因此在一个哈希问题中。

麻省理工公开课 - 计算机科学及编程导论课程节选