After a half-century,the search for extra-terrestrial intelligence, or SETI, has pretty much come up empty.

VOA: standard.2010.04.16

So it's hard to realize that in the terrestrial situation.

这在现实世界很难实现

耶鲁公开课 - 基础物理课程节选

advocates an expanded search for extra-terrestrial intelligence.

VOA: standard.2010.04.16