TED2014
Jeremy Kasdin: The flower-shaped starshade that might help us detect Earth-like planets
Jeremy Kasdin: Den blomsterformede stjerneskygger, som kan hjælpe os med at opdage jord-lignende planeter
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Astronomer tror, at hver stjerne i galaksen har en planet, en femtedel af hvilke kan rumme liv. Men vi har ikke set nogle af dem - endnu. Jeremy Kasdin og hans team arbejder på at ændre det med konstruktionen af et ekstraordinær stykke udstyr: en blomster kronblade-formet "stjerneskygger", som sætter teleskoper i stand til at fotografere planeter fra over 50.000 kilometer væk. Det er, siger han, den "sejeste mulige videnskab."
Jeremy Kasdin - Planet finder
Using innovative orbiting instruments, aerospace engineer Jeremy Kasdin hunts for the universe’s most elusive objects — potentially habitable worlds. Full bio
Using innovative orbiting instruments, aerospace engineer Jeremy Kasdin hunts for the universe’s most elusive objects — potentially habitable worlds. Full bio
Double-click the English transcript below to play the video.
00:12
The universe is teeming with planets.
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Universet er fyldt med planeter.
00:16
I want us, in the next decade,
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Jeg vil have ,at vi indenfor det næste årti
00:17
to build a space telescope that'll be able to image
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bygger et rumteleskop, som er i stand til at tage billeder
00:20
an Earth about another star
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af jordkloder kredsende om en anden stjerne,
00:22
and figure out whether it can harbor life.
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og finde ud af, om de kan rumme liv.
00:25
My colleagues at the NASA
Jet Propulsion Laboratory
Jet Propulsion Laboratory
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Mine kolleger hos NASA
Jet Propulsion Laboratory
Jet Propulsion Laboratory
00:27
at Princeton and I are working on technology
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ved Princeton og jeg arbejder på en teknologi,
00:30
that will be able to do just that in the coming years.
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som vil være i stand til netop det i de kommende år.
00:33
Astronomers now believe that every star
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Astronomer tror nu, at hver stjerne
00:35
in the galaxy has a planet,
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i galaksen har en planet,
00:37
and they speculate that up to one fifth of them
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og de formoder, at op i mod en femtedel af dem
00:39
have an Earth-like planet
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har en jord-lignende planet,
00:41
that might be able to harbor life,
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som kan rumme liv,
00:42
but we haven't seen any of them.
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men vi har ikke set nogle af dem.
00:44
We've only detected them indirectly.
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Vi har kun opdaget dem indirekte.
00:47
This is NASA's famous picture of the pale blue dot.
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Dette er NASA's berømte billede af den blege blå prik.
00:50
It was taken by the Voyager spacecraft in 1990,
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Det blev taget af Voyager rumskibet i 1990,
00:53
when they turned it around as
it was exiting the solar system
it was exiting the solar system
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da de vendte det rundt, imens det var på vej ud af solsystemet,
00:56
to take a picture of the Earth
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for at tage et billede af Jorden
00:57
from six billion kilometers away.
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fra seks milliarder kilometers afstand.
01:00
I want to take that
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Jeg ville tage sådan et
01:01
of an Earth-like planet about another star.
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af en jord-lignende planet kredsende om en anden stjerne.
01:04
Why haven't we done that? Why is that hard?
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Hvorfor har vi ikke gjort det? Hvorfor er det svært?
01:06
Well to see, let's imagine we take
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For at se det, lad os forestille os, at vi tager
01:08
the Hubble Space Telescope
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Hubble-rumteleskopet
01:10
and we turn it around and we move it out
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og vi vender det om, og vi flytter det ud
01:11
to the orbit of Mars.
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til Mars' omløbsbane.
01:13
We'll see something like that,
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Vi vil se noget som dette,
01:14
a slightly blurry picture of the Earth,
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et smule utydeligt billede af Jorden,
01:16
because we're a fairly small telescope
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fordi vi er et temmeligt småt teleskop
01:18
out at the orbit of Mars.
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ude ved Mars' omløbsbane.
01:20
Now let's move ten times further away.
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Lad os nu flytte ti gange længere væk.
01:22
Here we are at the orbit of Uranus.
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Her er vi ved Uranus' omløbsbane.
01:24
It's gotten smaller, it's got less detail, less resolve.
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Det er blevet mindre, det har færre detaljer, lavere opløsning.
01:26
We can still see the little moon,
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Vi kan stadig se den lille måne,
01:28
but let's go ten times further away again.
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men lad os gå 10 gange længere væk igen.
01:30
Here we are at the edge of the solar system,
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Her er vi ved kanten af vores solsystem,
01:32
out at the Kuiper Belt.
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ved Kuiperbæltet.
01:33
Now it's not resolved at all.
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Nu er der ingen opløsning overhovedet.
01:35
It's that pale blue dot of Carl Sagan's.
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Det er Carl Sagans blege blå prik.
01:38
But let's move yet again ten times further away.
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Men lad os igen flytte 10 gange længere væk.
01:40
Here we are out at the Oort Cloud,
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Her er vi ude ved Oortskyen,
01:41
outside the solar system,
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udenfor solsystemet.
01:43
and we're starting to see the sun
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og vi begynder at se solen
01:45
move into the field of view
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flytte ind i vores synsfelt,
01:46
and get into where the planet is.
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og flytte sig hen til hvor planeterne er.
01:47
One more time, ten times further away.
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En gang til, 10 gange længere væk.
01:50
Now we're at Alpha Centauri,
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Vi er nu ved Alfa Centauri,
01:51
our nearest neighbor star,
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vores tætteste nabostjerne,
01:52
and the planet is gone.
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og planeten er væk.
01:54
All we're seeing is the big beaming image of the star
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Alt hvad vi ser nu, er det store lysende billede af stjernen,
01:56
that's ten billion times brighter than the planet,
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som er ti milliarder gange mere lysende end planeten,
01:59
which should be in that little red circle.
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som burde være i den lille røde cirkel.
02:01
That's what we want to see. That's why it's hard.
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Det er, hvad vi vil se. Det er derfor, det er svært.
02:03
The light from the star is diffracting.
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Lyset fra en stjerne er afbøjende.
02:06
It's scattering inside the telescope,
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Det spreder sig inden i teleskopet,
02:07
creating that very bright image
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og skaber det meget lyse billede,
02:09
that washes out the planet.
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som vasker planeten ud.
02:11
So to see the planet,
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Så for at se den planet
02:12
we have to do something about all of that light.
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er vi nød til at gøre noget ved det lys.
02:14
We have to get rid of it.
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Vi er nød til at fjerne det.
02:15
I have a lot of colleagues working on
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Jeg har mange kolleger arbejdende på
02:17
really amazing technologies to do that,
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virkelig fantastiske teknologier for at gøre det,
02:19
but I want to tell you about one today
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men i dag vil jeg fortælle jer om en,
02:21
that I think is the coolest,
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som jeg synes er den sejeste,
02:22
and probably the most likely to get us an Earth
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og formentlig den mest sandsynlig til at skaffe os en Jord
02:24
in the next decade.
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i det næste årti.
02:26
It was first suggested by Lyman Spitzer,
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Det blev først foreslået af Lyman Spitzer,
02:28
the father of the space telescope, in 1962,
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faderen af rumteleskopet, i 1962,
02:31
and he took his inspiration from an eclipse.
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og han fik inspiration fra en solformørkelse.
02:33
You've all seen that. That's a solar eclipse.
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I har alle set det. Det er en solformørkelse.
02:35
The moon has moved in front of the sun.
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Månen er flyttet foran solen.
02:37
It blocks out most of the light
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Den fjerne det meste af lysten,
02:39
so we can see that dim corona around it.
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så vi kan se den svage korona omkring den,
02:42
It would be the same thing if I put my thumb up
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det ville være det samme, som hvis jeg tog min tommelfinger op
02:43
and blocked that spotlight
that's getting right in my eye,
that's getting right in my eye,
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og blokkerede for spotlyset, som rammer mig lige i mit øje.
02:46
I can see you in the back row.
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Jeg kan se jer på bagerste række.
02:48
Well, what's going on?
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Hvad sker der?
02:49
Well the moon
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Tja månen
02:51
is casting a shadow down on the Earth.
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kaster en skygge ned på jorden.
02:53
We put a telescope or a camera in that shadow,
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Vi putter en teleskop eller kamera i den skygge,
02:57
we look back at the sun,
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vi kigger tilbage på solen,
02:58
and most of the light's been removed
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og det meste af lyset er blevet fjernet,
03:00
and we can see that dim, fine structure
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og vi kan se den svage, fine struktur
03:02
in the corona.
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i koronaen.
03:03
Spitzer's suggestion was we do this in space.
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Spitzers forslag er at vi gør dette i rummet.
03:06
We build a big screen, we fly it in space,
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Vi bygger en stor sort skærm, og vi flyver det op i rummet,
03:09
we put it up in front of the star,
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vi placerer det foran en stjerne,
03:11
we block out most of the light,
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vi blokerer det meste af lyset,
03:12
we fly a space telescope in
that shadow that's created,
that shadow that's created,
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vi flyver et rumteleskop ind i skyggen, som er skabt,
03:15
and boom, we get to see planets.
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og bom vi kan se planeter.
03:17
Well that would look something like this.
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Det ville se nogenlunde sådan ud.
03:20
So there's that big screen,
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Så der er den store skærm,
03:22
and there's no planets,
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og der er ingen planeter,
03:22
because unfortunately it doesn't
actually work very well,
actually work very well,
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fordi uheldigvis virker det ikke særlig godt,
03:25
because the light waves of the light and waves
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fordi lysbølgerne fra lyset og bølgerne
03:28
diffracts around that screen
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bøjer omkring skærmen
03:29
the same way it did in the telescope.
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på samme måde, som det gjorde i teleskopet.
03:31
It's like water bending around a rock in a stream,
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Det er som vand bøjende omkring en sten i et vandløb,
03:34
and all that light just destroys the shadow.
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og al det lys ødelægger skyggen.
03:36
It's a terrible shadow. And we can't see planets.
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Det er en dårlig skygge. Og vi kan ikke se planeter.
03:39
But Spitzer actually knew the answer.
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Men Spitzer kendte allerede svaret.
03:41
If we can feather the edges, soften those edges
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Hvis vi kan sammenfjedre de kanter, blødgøre de kanter,
03:43
so we can control diffraction,
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så vi kan kontrollere afbøjning,
03:45
well then we can see a planet,
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så kan vi se en planet,
03:47
and in the last 10 years or so we've come up
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og i de sidste 10 år eller deromkring, har vi fundet
03:48
with optimal solutions for doing that.
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optimale løsninger på at gøre det.
03:50
It looks something like that.
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Det ser nogenlunde sådan ud.
03:54
We call that our flower petal starshade.
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Vi kalder det vores kronblade-stjerneskygger.
03:56
If we make the edges of those petals exactly right,
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Hvis vi indstiller kanterne af de kronblade helt korrekt,
03:59
if we control their shape,
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hvis vi kontrollerer deres form,
04:01
we can control diffraction,
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kan vi kontrollere afbøjning,
04:02
and now we have a great shadow.
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og nu har vi en fremragende skygge.
04:04
It's about 10 billion times dimmer than it was before,
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Det er omkring 10 milliarder gange svagere, end det var før,
04:06
and we can see the planets beam out just like that.
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og vi kan se planeterne udstråle lige sådan.
04:10
That, of course, has to be bigger than my thumb.
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Den er, selvfølgelig, nødt til at være større end min tommelfinger.
04:12
That starshade is about
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Denne stjerneskygger er omkring
04:13
the size of half a football field
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halv så stor som en amerikansk fodboldbane,
04:15
and it has to fly 50,000 kilometers
away from the telescope
away from the telescope
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og den er nødt til at flyve 50.000 kilometer væk fra teleskopet,
04:18
that has to be held right in its shadow,
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som skal holdes lige i dens skygge,
04:20
and then we can see those planets.
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og så kan vi se de planeter.
04:22
This sounds formidable,
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Dette lyder fantastisk,
04:24
but brilliant engineers, colleagues of mine at JPL,
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men glimrende ingeniører, mine kolleger hos JPL,
04:27
came up with a fabulous design for how to do that
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fandt på et fremragende design for hvordan det kan gøres,
04:30
and it looks like this.
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og det ser sådan ud.
04:31
It starts wrapped around a hub.
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Det starter pakket omkring en hub.
04:32
It separates from the telescope.
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Det separerer sig fra teleskopet.
04:34
The petals unfurl, they open up,
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Kronbladene udfolder sig, de åbner sig op,
04:37
the telescope turns around.
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teleskopet drejer omkring.
04:38
Then you'll see it flip and fly out
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Så vil I se den vende omkring og flyve
04:41
that 50,000 kilometers away from the telescope.
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de 50.000 kilometer væk fra teleskopet.
04:44
It's going to move in front of the star
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Den vil flytte sig ind foran stjernen,
04:46
just like that, creates a wonderful shadow.
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således, og skabe en vidunderlig skygge.
04:50
Boom, we get planets orbiting about it.
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Bom, vi har planeter kredsende omkring den.
04:53
(Applause)
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(Bifald)
04:55
Thank you.
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Tak.
04:57
That's not science fiction.
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Det er ikke science fiction.
04:59
We've been working on this
for the last five or six years.
for the last five or six years.
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Vi har arbejdet på dette de seneste fem eller seks år.
05:02
Last summer, we did a really cool test
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Sidste sommer, udførte vi en virkelig sej test
05:05
out in California at Northrop Grumman.
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ude i Californien ved Northrup Grumman.
05:07
So those are four petals.
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Så disse er fire kronblade.
05:09
This is a sub-scale star shade.
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Dette er en mindre udgave af stjerneskyggeren.
05:10
It's about half the size of the one you just saw.
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Den er omkring halvt så stor, som den I lige så.
05:13
You'll see the petals unfurl.
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I vil se kronbladene udfolde sig.
05:14
Those four petals were built by four undergraduates
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De fire kronblade blev bygget af fire studerende,
05:16
doing a summer internship at JPL.
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som var i sommerpraktik hos JPL.
05:19
Now you're seeing it deploy.
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Nu ser I den udfolde sig.
05:20
Those petals have to rotate into place.
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Kronbladene skal rotere på plads.
05:22
The base of those petals
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Basen af de kronblade
05:23
has to go to the same place every time
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er nødt til at gå til det samme sted hver gang
05:26
to within a tenth of a millimeter.
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til indenfor en tiendedel af en millimeter.
05:27
We ran this test 16 times,
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Vi gennemførte denne test 16 gange,
05:29
and 16 times it went into the exact same place
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og 16 gange gik den til det nøjagtigt samme sted
05:32
to a tenth of a millimeter.
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til en tiendedel af en millimeter.
05:33
This has to be done very precisely,
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Dette skal gøres meget nøjagtigt,
05:35
but if we can do this, if we can build this technology,
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men hvis vi kan gøre det, hvis vi kan bygge den teknologi,
05:38
if we can get it into space,
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hvis vi kan få den op i rummet,
05:39
you might see something like this.
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vil I måske se nogen som dette.
05:41
That's a picture of one our nearest neighbor stars
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Det er et billede taget af en af vores nærmeste nabostjerner
05:43
taken with the Hubble Space Telescope.
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taget af Hubble-rumteleskopet.
05:46
If we can take a similar space telescope,
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Hvis vi kan tage et lignende rumteleskop,
05:48
slightly larger,
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en smule større,
05:49
put it out there,
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putte det derud,
05:51
fly an occulter in front of it,
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flyve en mørkelægger ind foran det,
05:52
what we might see is something like that --
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er hvad vi måske vil se noget som det --
05:54
that's a family portrait of our
solar system -- but not ours.
solar system -- but not ours.
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det er et familieportræt af vores solsystem -- men ikke vores.
05:57
We're hoping it'll be someone else's solar system
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Vi håber på, at det vil være nogen andres solsystem
06:00
as seen through an occulter,
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set igennem en mørkelægger
06:02
through a starshade like that.
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igennem en stjerneskygger som den.
06:03
You can see Jupiter, you can see Saturn,
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I kan se Jupiter, I kan se Saturn,
06:05
Uranus, Neptune, and right there in the center,
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Uranus, Neptun, og lige der i midten,
06:07
next to the residual light
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ved siden af residuallyset,
06:09
is that pale blue dot. That's Earth.
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er den blege blå prik. Det er Jorden.
06:11
We want to see that, see if there's water,
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Vi vil se dét, se om der er vand,
06:13
oxygen, ozone,
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ilt, ozon,
06:14
the things that might tell us that it could harbor life.
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de ting som kan fortælle os, om den kan rumme liv.
06:17
I think this is the coolest possible science.
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Jeg synes, at det er den sejest mulige videnskab.
06:19
That's why I got into doing this,
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Det er derfor, jeg gik ind i dette felt,
06:21
because I think that will change the world.
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fordi jeg tror, at det vil ændre verden.
06:23
That will change everything when we see that.
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Det vil ændre alt, når vi ser det.
06:25
Thank you.
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Tak.
06:27
(Applause)
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(Bifald)
ABOUT THE SPEAKER
Jeremy Kasdin - Planet finderUsing innovative orbiting instruments, aerospace engineer Jeremy Kasdin hunts for the universe’s most elusive objects — potentially habitable worlds.
Why you should listen
At Princeton’s High Contrast Imaging Laboratory, Jeremy Kasdin is collaborating on a revolutionary space-based observatory that will unveil previously unseen (and possibly Earth-like) planets in other solar systems.
One of the observatory’s startling innovations is the starshade, an orbiting "occulter" that blocks light from distant stars that ordinarily outshine their dim planets, making a clear view impossible. When paired with a space telescope, the starshade adds a new and powerful instrument to NASA’s cosmic detection toolkit.
More profile about the speakerOne of the observatory’s startling innovations is the starshade, an orbiting "occulter" that blocks light from distant stars that ordinarily outshine their dim planets, making a clear view impossible. When paired with a space telescope, the starshade adds a new and powerful instrument to NASA’s cosmic detection toolkit.
Jeremy Kasdin | Speaker | TED.com