每天一小段英语（20）

命运号角

Moving back to just our galaxy, and doing the same math on the lowest estimate for stars in the Milky Way (100 billion), we’d estimate that there are 1 billion Earth-like planets and 100,000 intelligent civilizations in our galaxy.
回到我们太阳系，如果太阳系有1000亿颗恒星，那么就有10亿颗类地行星，10万种智能文明。

SETI (Search for Extraterrestrial Intelligence) is an organization dedicated to listening for signals from other intelligent life. If we’re right that there are 100,000 or more intelligent civilizations in our galaxy, and even a fraction of them are sending out radio waves or laser beams or other modes of attempting to contact others, shouldn’t SETI’s satellite dish array pick up all kinds of signals?
SETI (Search for Extraterrestrial Intelligence)是一个致力于收集外星文明信号的组织。如果太阳系真的有10万或更多外星文明，甚至一小部分正在发送无线电波、激光或者其他方法试图联系其他文明，为什么SETI的卫星天线阵列没有收到任何形式的信号？

But it hasn’t. Not one. Ever.
真的一次都没收到。

Where is everybody?
他们在哪？


It gets stranger. Our sun is relatively young in the lifespan of the universe. There are far older stars with far older Earth-like planets, which should in theory mean civilizations far more advanced than our own. As an example, let’s compare our 4.54-billion-year-old Earth to a hypothetical 8-billion-year-old Planet X.
情况变得复杂了。太阳相对于宇宙来说还很年轻，理论来讲年老恒星的类地行星上外星文明应该比地球文明更先进。假设有一个80亿年的行星X，我们用它和我们4.54亿年的地球做比较。

命运号角

每日一词
relatively
adv. 相当地；相对地，比较地

命运号角

satellite dish array
卫星天线阵列

天各一方8

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shakencity

Moving back to just our galaxy, and doing the same math on the lowest estimate for stars in the Milky Way (100 billion), we’d estimate that there are 1 billion Earth-like planets and 100,000 intelligent civilizations in our galaxy.

shakencity

  

shakencity

  

shakencity