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  • Space isn’t as empty as you might think;

  • in between the stars, there’s lots of dust and gas, what’s known as the interstellar medium.

  • This is the stuff that makes planets and possibly, life.

  • Most of the interstellar medium is made up of simple atoms, like hydrogen and helium,

  • but there’s a lot more out there that weve never been able to identify.

  • That is, until the Hubble Space Telescope, that venerable old workhorse, called DIBs.

  • By DIBs I mean Diffuse Interstellar Bands.

  • It's a pun.

  • To get it, it’s probably best if you understand how we figure out what’s floating around out there in space.

  • Stars give off light. Obviously.

  • And for that light to reach us, it has to travel through all that dust and gas between the star and us.

  • When it hits these atoms and molecules, some wavelengths of light get absorbed.

  • Once the light finally reaches us, we can split it into a spectrum,

  • and the absorbed wavelengths appear as dim or missing bands.

  • These bands are like the element’s or compound’s fingerprint.

  • All we have to do then is match the absorption spectrum to that of known elements or molecules, and bingo,

  • weve got an idea of what’s floating around out there in the beyond.

  • Well, easier said than done.

  • Identifying the absorption spectrum of single atoms is a piece of cake,

  • there’s only so many elements and we can catalogue the patterns they make easily.

  • But the tricky thing about atoms is that they combine with one another in all sorts of arrangements,

  • and when they do, the absorption pattern they make gets more complicated.

  • When we observe starlight, a broad range of colors are missing,

  • and in patterns unlike any known atoms or molecules on Earth.

  • These are the Diffuse Interstellar Bands, or DIBs.

  • There. Now you can go back to the start of the video and laugh.

  • Masterful joke telling, Julian.

  • We have spotted over 400 DIBs,

  • but until recently we haven’t been able to conclusively identify any of them despite decades of trying.

  • There are just millions of molecules to test them against, it would take lifetimes to go through them all.

  • Making the task even harder, water vapor in Earth’s atmosphere

  • can prevent ground-based telescopes from spotting absorption patterns.

  • That’s where Hubble and a little luck comes into play.

  • Up above most of the atmosphere, the telescope had an unobstructed view to observe the DIBs.

  • It peered at blue supergiant stars right along our galactic plane,

  • where the light would have to travel through the most gas and dust.

  • Even so, the aging hardware had to be pushed beyond its usual sensitivity limits.

  • And joy of joys, it actually spotted an absorption pattern scientists recognized.

  • Hubble picked up the signature of a molecule called C60.

  • C60 is, as you might have guessed, made up of 60 carbon atoms arranged in a hollow sphere.

  • It resembles a soccer ball, or the famous geodesic domes of Buckminster Fuller,

  • so it’s also known as Buckminsterfullerene, or Buckyballs.

  • C60 has been spotted in space before, but Hubble detected a version of it

  • that has been ionized by ultraviolet light.

  • Stripped of an electron, these buckyballs are positively charged so theyre technically C60+,

  • and this marks the first time theyve been seen in the interstellar medium.

  • Confirming C60+ has some interesting implications.

  • First, it shows just how complex molecules in space can get.

  • Before C60 was spotted, the next most complex compound was made up of just 12 atoms.

  • The ionized form of C60 shows that these large molecules

  • can form even in harsh ultraviolet-irradiated environments.

  • And the team that found it thinks this points to other large complex carbon-based molecules

  • that can explain many of the still unidentified DIBs.

  • This could be a huge clue as to how life itself started.

  • All life weve seen is carbon based

  • because the element is perfect for bonding with other atoms to make molecules.

  • If carbon-based molecules can spontaneously occur in the interstellar soup that gives rise to planets,

  • maybe theyre the seed from which life springs.

  • Still, there are a lot more DIBs that need explaining,

  • but thanks to Hubble and some spheres of carbon, we think were on the right track.

  • Buckminsterfullerene has also rarely been spotted here on Earth in rocks,

  • minerals, and soot from high-temperature combustion.

  • If you liked this video, check out this video Maren did on schwarzites.

  • Make sure to subscribe and I’ll see you next time on Seeker.

Space isn’t as empty as you might think;

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B2 中高級

我們剛剛找到了關於生命如何在宇宙中起源的重要線索,這要歸功於Buckyballs。 (We Just Found a MAJOR Clue About How Life Started in the Universe Thanks to Buckyballs)

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    林宜悉 發佈於 2021 年 01 月 14 日
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