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  • - I'm here with Philipp Heck, who is the Robert A. Pritzker, Associate Curator of MeteachsadfaaMeteoraww shoot...


  • - The Robert A. Pritzker, Associate Curator for Meteoritics and Polar Studies.


  • - There. - I practiced this many times.

    沒錯。 - 我練習過很多次了。

  • - Yeah. Today we're going to talk about the age of the solar system.


  • -These large, white, aluminum ridge inclusions that you can see here, these are the oldest minerals that formed in the solar system,


  • and they can be dated, and it' basically the start of the solar system. We call it T-0, time 0. It's 4.567 billion years.

    而且能夠判定其年代大約是在太陽系一開始就有的。我們把它叫做 T-0,時間零點,也就是四十五億六千七百萬年前。

  • It's an easy number to remember. 4.567 billion.


  • - We know how old the solar system is because of this specific specimen. - Exactly, exactly. This defines T-0.

    我們就是靠這個樣本才知道太陽系有多老的。 - 正是如此,正是如此。它決定了 T-0。

  • When I give public talks, I usually give people a slice in plastic, and I say "You can hold the oldest piece of material in the solar system."


  • And, even, you don't see it, but the oldest material available to anyone on this planet is in there.


  • There's nothing older that you can touch. - Wow.

    你能摸得到的東西沒有比這更古老的了。 - 哇。

  • - Pre-solar grains. They're older than the sun, older than the meteorite itself.


  • Some of them might be as old as 5.5 billion years. - And how do you know that?

    它們有一些可能已經有五十五億年那麼老了。 - 你怎麼知道的?

  • - So these pre-solar grains, they can be analyzed chemically.


  • Their isotopic composition is highly anomalous, very different than anything in the Solar System.


  • Their composition cannot be explained by any process that can occur in the Solar System.


  • The fact that they are embedded in that rock tells us they could not have been incorporated later;


  • They must have been part of that mixture from which the rock formed.


  • And since the rock formed 4.6 billion years ago, they must be older. - Older the 4.6 billion years.

    而因為那顆石頭組成於四十六億年前,它們一定比那更老。 - 比四十六億年更老。

  • - And some minerals even can be dated. So far we have only dated approximately 30 grains.


  • Most of them are about 200 million years older than the sun.


  • And a few of them are about a billion years older than the sun, which makes them about 5.6 billion years old.


  • We think the solar system formed, basically from a cloud of gas and dust, and this cloud of gas and dust formed from different sources, from different stars.


  • Some of these stars were indeed stellar explosions, supernovae. They exploded, and during these explosions, new elements formed.


  • After the matter cooled down, some of this matter condensed as gas.


  • There were other starsmany other starswhich were like the sun, but they were already at the end of their life.


  • They expanded, became red giants, and expelled the matter into space. And from all these mixtures of stellar ejecta, this pre-solar cloud formed.


  • Within this pre-solar molecular cloud, the protosolar disk formed. It's basically a rotating disk of gas and dust.


  • The protosun formed, and later, the sun. Planetary building blocks formed.


  • Most of the matter was alteredheatedthe pre-solar signature is not visible anymore, but some of this pre-solar matter survived without having been altered.


  • That's whats trapped in hereit's only a tiny fraction. The most abundant type of pre-solar materials are diamondsnano-diamonds.


  • These diamonds are tinythey're only 2 nanometers acrossmaybe consist of 1000 to 2000 carbon atoms. We can extract them from meteorites.


  • We basically dissolve everything else, just are left with the acid residue of diamondsand in this little vial I have billions of diamonds.


  • You normally wouldn't see them because they are so small they wouldn't scatter light, but they clump togetheras you can see, that white residue


  • - Yeah - These are all diamonds. It's literally stardust.

    - 對呀。 這些全是鑽石。名副其實的星塵。

  • - It's awfully ethereal looking. Kind of like floats around in this nebulousness.


  • -These diamonds, they were discovered in Chicago, in 1987, at the University of Chicago, with a Field Museum meteorite.


  • -Really?'s overwhelming.


  • It's...It's— How did you... how did you get into this?


  • - Yeah, so when I heard about this first, I was extremely fascinated, and I heard about it when I was a student of earth science in Switzerland,


  • and did an undergraduate project in a cosmo-chemistry lab there. "This is so fascinating, would it be possible to do a PhD there?" -Yeah

    而且在那兒參與了一項大學部的宇宙化學實驗室的研究計畫。我想:「太有意思了,能不能在這裡做博士研究啊?」 - 對呀。

  • - Just because I was completely hooked. I was always interested in astronomy, and volunteered at the local observatory there, and thought, "Oh, if I could do that for a living, that would be fantastic."


  • And, yeah, actually, the opportunity came up, and I was able to work on the stardust duringfor my PhD. -Really?

    然後,對呀,機會真的來了,我在攻讀博士時真的參與了星塵的研究。 - 真的哦?

  • - And everything, yeah, so I'm very fortunate to work on such a very—I would sayon the oldest matter that is available anywhere on this planet.


  • It keeps us very motivated, and it's really great. -Yeah

    這讓我們興趣盎然,真的很棒。 - 對呀

  • - With every question that you answer, you open 10 more questions that can be studied, but then you have to make a wise decision, which questions are actually worth pursuing to answer?


  • -Yeah. - Worth the time and money. And one of these is the origin of those nano-diamonds.

    - 對呀。 要值得花時間跟經費。而追尋奈米鑽石來源就是這種問題。

  • Because nano-diamonds are basically pure carbon, and they survived the formation and evolution of our Solar Systemand almost nothing else did survivealmost everything has been altered.


  • So the carbon in our body and our skin, you don't see a pre-solar signature anymore. - Yeah

    但是在我們身體裡跟皮膚上的碳,你就看不到太陽系誕生的痕跡了。 - 對呀。

  • - Although it might have the same origin as these diamonds. -So, the carbon that makes up those diamonds is the same carbon that makes uplike the carbon within me and you.

    儘管它跟這些鑽石的來源是一樣的。 - 所以構成這些鑽石的碳跟你我身體裡的碳是一樣的。

  • - Exactly. - And all of life on Earth.

    正是如此。 - 而且所有地球上的生物也是。

  • - Exactly. - So this is like our great times infinitygreat, greatancestor, essentially.

    沒錯。 - 所以這等於是我們的很古老很古老以前的老祖宗了。

  • - Yeah, so I think we have a common origin. - Yeah.

    對呀,所以我認為我們有一個共同的起源。 - 對呀。

  • - These diamonds, and life on Earth, and this is a proxy ofit's basically the tiny fraction that survived all these billions of years since the planets and the Earth formed.


  • And by studying those diamonds, they open upthey are like a time capsule. By studying them, we can learn about the pastabout the time before the Solar System.


  • (So if you were to take those diamonds down to a pawn shop, how much is one of them worth?)


  • - He would not even know.


  • - I don't know, but I always tellthey probably wouldn't make nice engagement rings, because they are so small, but there are millions!


- I'm here with Philipp Heck, who is the Robert A. Pritzker, Associate Curator of MeteachsadfaaMeteoraww shoot...



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B1 中級 中文 鑽石 太陽系 物質 古老 奈米 形成

星形材料和納米鑽石 (Starstuff and Nanodiamonds)

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    Hhart Budha 發佈於 2021 年 01 月 14 日