It’s described in the article: > Sounding a more ominous note are concepts such as the “great filter”—the idea that there is something that always limits a spe

It’s described in the article: > Sounding a more ominous note are concepts such as the “great filter”—the idea that there is something that always limits a species, perhaps an inevitable failure to achieve that green revolution, leading to an implosive extinction of all potentially technological life.