If it were possible, however, it would present some pretty knotty paradoxes... For example, what if someone or something traveled back in time and changed the ensuing future? And have you heard the one about the time traveler who dots back and forward in time and by means of various medical technologies is able to be his own father AND mother?! And besides, if time travel is possible, where are all the people from the future--surely they'd want to come and meet us poor stranded 21st century beings?
    然而，如果這一切成為可能的話，那么將會(huì)出現(xiàn)一些非常令人困惑的邏輯混亂……比如，如果某人或某物逆時(shí)間旅行并改變隨之發(fā)生的情況，那會(huì)發(fā)生什么情況呢？又比如說(shuō)，你是否曾聽(tīng)說(shuō)過(guò)這樣的事情——一位時(shí)間旅行者在時(shí)間隧道中穿梭往返，利用各種醫(yī)學(xué)技術(shù)使自己成為自己的父親和母親？還有，如果時(shí)間旅行成為可能，未來(lái)的所有人都會(huì)在哪里呢？他們肯定想來(lái)見(jiàn)見(jiàn)我們這些滯留在21世紀(jì)的可憐人。