(单词翻译:单击)
The Fermi paradox is based on a question asked by a scientist named Enrico Fermi: if the universe is so large, why haven’t we found intelligent life yet?
费米悖论的产生是基于科学家恩利克·费米提出的一个问题：如果宇宙如此之大，那么为什么我们还没有发现智慧生命?
Although it is a very simple question, it has confused scientists for decades.
虽然这是一个非常简单的问题，但几十年来它一直困扰着科学家。
The universe has existed for over 13 billion years, but our planet is only about 4.5 billion years old.
宇宙已经存在了超过130亿年，但地球只有大约45亿年的历史。
Fermi believed that if human life could develop so quickly, there surely had to be older, more advanced civilizations out there.
费米相信，如果人类能发展得如此之快，那么肯定会有更古老、更先进的文明存在。
These civilizations likely would be capable of interstellar travel.
这些文明很可能具备星际旅行的能力。
If this is true, then aliens should have contacted us already.
如果这是真的，那么外星人早该联系上我们了。
Many people have proposed explanations since Fermi first asked the question in 1950.
自1950年费米首次提出这个问题以来，许多人作出了解释。
One possibility is something called a Great Filter, which is a hypothetical barrier that stops most types of life from developing past a certain point.
其中一种解释是存在所谓的“大过滤器”，这是一个假想的屏障，可以阻止大多数生命的进化超过某一界限。
