20xxted英語演講我們從何而來(編輯修改稿)
2025-01-16 23:10 本頁面
【文章內(nèi)容簡介】 ntaneously on the Earth, so it must be possible for life to appear on other suitable planets, of which there seem to be a large number in the galaxy.
現(xiàn)在我轉(zhuǎn)到第二個大問題去，宇宙中就只有我們，還是另有其它生物?我們相信生命從地球自我衍生，故此生命確有可能出現(xiàn)於其它合適星球。星河中看來可有不少呢。
But we donamp。39。t know how life first appeared. We have two pieces of observational evidence on the probability of life appearing. The first is that we have fossils of algae from billion years ago. The Earth was formed billion years ago and was probably too hot for about the first half billion years. So life appeared on Earth within half a billion years of it being possible, which is short pared to the 10billionyear lifetime of a planet of Earth type. This suggests that the probability of life appearing is reasonably high. If it was very low, one would have expected it to take most of the ten billion years available.
但我們?nèi)晕磾囃ㄉ侨绾紊桑簩渡Q生的可能契機(jī)，我們有兩項觀測得來的佐證。首先我們有來自35億年前的海藻化石。地球于46億年前形成，頭約5億年相信仍太熱了。故此生命于其變得可能后的5億年間方出現(xiàn)，這相對于像地球之類百億年期的星體，只算是一段短時間。這意味著生命出現(xiàn)的概率是頗高的。若是低的話，就可預(yù)期要花盡百億年的絕大部分才會出現(xiàn)。
On the other hand, we donamp。39。t seem to have been visited by aliens. I am discounting the reports of would they appear only to cranks and weirdos? If there is a government conspiracy to suppress the reports and keep for itself the scientific knowledge the aliens bring, it seems to have been a singularly ineffective policy so far. Furthermore, despite an extensive search by the SETI project, we havenamp。39。t heard any alien television quiz shows. This probably indicates that there are no alien civilizations at our stage of development within a radius of a few hundred light years. Issuing a
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