教室里温暖宜人,萨迪斯·费区教授正忙着板书,身后是一片笔尖勤奋地划过笔记本纸面的沙沙声、日光灯管的嗡嗡声和脚步移动声,沙滩男孩的歌声顺着敞开的窗户从院子里飘进来。“也就是说,”他继续说道,“回到过去这件事违反了因果论的原则,因此似乎是不可能实现的。”他转身面向学生,“通常我们都会用‘祖父悖论’来举例说明。 The classroom is warm and warm, Professor Sadis Fee District is busy with the blackboard, behind the tip of a pen is diligently across the surface of notebook paper, the buzz of fluorescent tubes and footsteps move, the beach boy’s song along the open The windows float in from the yard. ”He continued, “ Returning to the past is a violation of the principle of causality and therefore seems impossible to do. ”He turned to face the student, “ Often we would use the ”grandfather Paradox ’to illustrate.