Are We Alone in the Universe?
Listen.
Do you hear anything? Me neither.
It's pretty deserted out here.
For the past 50 years, astronomers have been using radio dishes to eavesdrop on the cosmos.
They are listening for signals from alien civilizations.
But so far, it's been pretty silent.
That begs the question: Are we alone in a cosmic desert?
In 1961, astronomer Frank Drake, came up with a way to approach the question mathematically.
He created an equation that estimates how many alien cultures inhabit our galaxy.
The equation depends on a bunch of factors.
First, the number of new stars born each year, times the fraction of stars with planets, times the number of planets that could potentially support life in each planetary system, times the fraction of life-supporting planets where life actually takes hold, times the percentage of planets with life forms that develop intelligence, times the fraction of intelligent species that develop the ability to broadcast signals across interstellar space, times how long those civilizations are likely to survive, or at least how long they'll broadcast their signals into space.
translation
sentence:
听。 你听到什么了吗?我也没。 这里很荒凉。 在过去的50年里，天文学家一直在使用无线电天线来窃听宇宙。 他们在监听来自外星文明的信号。 但到目前为止，它还很安静。 这就引出了一个问题:在宇宙沙漠中，我们是孤独的吗? 1961年，天文学家弗兰克·德雷克提出了一种数学方法来解决这个问题。 他创造了一个方程来估计银河系中有多少外星文化。 这个方程取决于很多因素。 首先，每年新诞生的恒星的数量，乘以有行星的恒星的比例，乘以每个行星系中可能支持生命的行星的数量，乘以有生命存在的行星的比例，乘以有生命发展出智能的行星的比例，乘以有能力在星际空间传播信号的智能物种的比例，乘以这些文明可能存活的时间，或者至少是他们向太空发射信号的时间。
Multiply all those together and you get "N", the number of detectable civilizations in the galaxy.
It's a long equation and astronomers only have estimates for some of the factors; the ones we can observe from Earth, like how many stars are born each year.
On the other hand, we don't know much about how life develops on other worlds.
Many experts think that alien microbes and slime molds may be common.
But little green men? Not so much.
Perhaps the biggest question is the value of "L" in the Drake equation.
How long will a given civilization last before dying out or self-destructing?
"L" could be hundreds of years or it could be billions.
Humankind has only used technology; like radio broadcasts for a century or so and in that short time, we've already had a few close shaves.
So the lifetime of a given civilization could be rather short.
If that's the case, we may be alone in the cosmic desert after all.
translation
sentence:
把这些都乘在一起，你就得到了“N”，即银河系中可探测到的文明的数量。 这是一个很长的方程，天文学家只估计了一些因素;我们可以从地球上观测到，比如每年有多少颗恒星诞生。 另一方面，我们对其他星球上的生命是如何发展的知之甚少。 许多专家认为外来微生物和黏菌可能很常见。 但是小绿人呢?没那么多。 也许最大的问题是“L”在德雷克方程中的值。 一个特定的文明在消亡或自我毁灭之前能持续多久? L可以是几百年，也可以是几十亿年。 人类只使用了技术;就像一个世纪左右的无线电广播一样，在这么短的时间里，我们已经有过几次死里逃生的经历。 所以一个特定文明的寿命可能相当短。 如果是这样的话，我们可能在宇宙沙漠中是孤独的。
words
[
{
"name": "neither",
"trans": [
"conj. 〈古〉也不",
"adv. 两者都不；（否定的陈述同样适用于其他人或物）也不",
"adj. (两者)都不的",
"pron. 两者中无…"
],
"usphone": "'ˈniːðər'",
"ukphone": "''"
},
{
"name": "deserted",
"trans": [
"adj. 空无一人的，空旷的；被遗弃的，被抛弃的； 废弃的",
"v. 离弃，舍弃（某地）；抛弃，遗弃（某人）；背弃，放弃（**** 的过去式和过去分词）"
],
"usphone": "'dɪˈzɜːrtɪd'",
"ukphone": "''"
},
{
"name": "astronomer",
"trans": [
"n. 天文学家"
],
"usphone": "'əˈstrɑːnəmər'",
"ukphone": "''"
},
{
"name": "radio dish",
"trans": [
"天线盘"
],
"usphone": "''",
"ukphone": "''"
},
{
"name": "eavesdrop",
"trans": [
"v. 偷听，窃听"
],
"usphone": "'ˈiːvzdrɑːp'",
"ukphone": "''"
},
{
"name": "cosmos",
"trans": [
"n. 宇宙；完整和谐的一统体系；秋英属植物"
],
"usphone": "'ˈkɑːzmoʊs'",
"ukphone": "''"
},
{
"name": "alien civilization",
"trans": [
"外星文明"
],
"usphone": "''",
"ukphone": "''"
},
{
"name": "so far",
"trans": [
"到目前为止"
],
"usphone": "''",
"ukphone": "''"
},
{
"name": "cosmic",
"trans": [
"adj. 宇宙的，外层空间的；巨大的，极重要的；精神的，神灵的"
],
"usphone": "'ˈkɑːzmɪk'",
"ukphone": "''"
},
{
"name": "come up",
"trans": [
"na. 来；发芽；抬头；发作",
"走近；是出现的意思；雾中慢慢出现"
],
"usphone": "''",
"ukphone": "''"
},
{
"name": "equation",
"trans": [
"n. 等式，方程（式）；等同（看待）；（必须考虑多种因素的）复杂局面（或问题）"
],
"usphone": "'ɪˈkweɪʒ(ə)n'",
"ukphone": "''"
},
{
"name": "inhabit",
"trans": [
"v. 居住于，栖居在；存在于，占据"
],
"usphone": "'ɪnˈhæbɪt'",
"ukphone": "''"
},
{
"name": "factor",
"trans": [
"n. 因素，要素；等级，系数；因数，因子；遗传因子，基因；（血液中的）凝血因子；代理公司，代理商；<苏格兰>地产管理人，管家；测量水平",
"v. 把……作为因素计入，把……包括在内（factor in）；把……作为因素排除，不把……包括在内（factor out）；将……分解为因子；代理经营，（代管）产业；做代理商"
],
"usphone": "'ˈfæktər'",
"ukphone": "''"
},
{
"name": "fraction",
"trans": [
"n. 分数，小数；小部分，微量；持不同意见的小集团；分离；（基督教用语）分切圣餐面包"
],
"usphone": "'ˈfrækʃ(ə)n'",
"ukphone": "''"
},
{
"name": "potentially",
"trans": [
"adv. 可能地，潜在地"
],
"usphone": "'pəˈtenʃəli'",
"ukphone": "''"
},
{
"name": "take hold",
"trans": [
"生效，确立，流行",
"抓住，握紧，扎根"
],
"usphone": "''",
"ukphone": "''"
},
{
"name": "interstellar",
"trans": [
"adj. 星际的， 恒星之间的"
],
"usphone": "'ˌɪntərˈstelər'",
"ukphone": "''"
},
{
"name": "detectable",
"trans": [
"adj. 可检测的；可发觉的"
],
"usphone": "'dɪˈtektəb(ə)l'",
"ukphone": "''"
},
{
"name": "microbe",
"trans": [
"n. 细菌，微生物"
],
"usphone": "'ˈmaɪkroʊb'",
"ukphone": "''"
},
{
"name": "slime",
"trans": [
"n. 黏液；烂泥",
"vt. 涂泥",
"vi. 变粘滑"
],
"usphone": "'slaɪm'",
"ukphone": "''"
},
{
"name": "mold",
"trans": [
"n. 模具；铸模；模制品；类型，个性，风格；框架；体型，模样；霉，霉菌；耕作土壤；松软沃土",
"v. 浇铸，塑造；用模子制作；对……影响重大；将……塑造成；使）紧贴于，吻合；轮廓相符；使发霉"
],
"usphone": "'moʊld'",
"ukphone": "''"
},
{
"name": "perhaps",
"trans": [
"adv. 可能；（用以缓和语气或表示礼貌）也许，可能；（委婉地表示不赞同或不接受）也许，大概；（用于提出建议或请求）也许",
"n. 假定，猜想"
],
"usphone": "'pərˈhæps'",
"ukphone": "''"
},
{
"name": "dying out",
"trans": [
"na. 死绝",
"消灭；衰灭消失；衰灭死去"
],
"usphone": "'ˈdaɪɪŋ aʊt'",
"ukphone": "''"
},
{
"name": "shave",
"trans": [
"v. 剃（须），刮去（毛发）；削去，刮掉（薄层）；（少量地）减去，削减；掠过，擦过",
"n. 刮脸，剃毛发 ；剃刀，刮刀； <非正式> 侥幸逃过，幸免（close ****）"
],
"usphone": "'ʃeɪv'",
"ukphone": "''"
},
{
"name": "after all",
"trans": [
"na. 毕竟；终究；最后",
"都会有无限的可能；不管怎么说；最终的真谛"
],
"usphone": "''",
"ukphone": "''"
}
]