Garik Israelian: What's inside a star?

47,516 views ・ 2009-10-01

TED


Please double-click on the English subtitles below to play the video.

Prevodilac: Sofija Dorotic Lektor: Ana Zivanovic-Nenadovic
00:18
I have a very difficult task.
0
18330
3000
Imam jako težak zadatak.
00:21
I'm a spectroscopist.
1
21330
3000
Spektroskopista sam.
00:24
I have to talk about astronomy without showing you
2
24330
2000
Treba da vam pričam o astronomiji, a da vam ne pokažem
00:26
any single image of nebulae or galaxies, etc.
3
26330
4000
ijednu sliku nebule, galaksije i tako dalje.
00:30
because my job is spectroscopy.
4
30330
2000
Ja radim kao spektroskopista
00:32
I never deal with images.
5
32330
3000
i nikada ne radim sa fotografijama.
00:35
But I'll try to convince you
6
35330
2000
Pokušaću da vas uverim
00:37
that spectroscopy is actually something which can
7
37330
2000
da je spektroskopija nešto
00:39
change this world.
8
39330
3000
što može promeniti svet.
00:42
Spectroscopy can probably answer the question,
9
42330
3000
Spektroskopija verovatno može da odgovori na pitanje
00:45
"Is there anybody out there?"
10
45330
2000
"Ima li koga tamo?"
00:47
Are we alone? SETI.
11
47330
2000
Da li smo sami? SETI.
00:49
It's not very fun to do spectroscopy.
12
49330
3000
Spektroskopija nije jako zabavna.
00:52
One of my colleagues in Bulgaria,
13
52330
2000
Jedna moj koleginica iz Bugarske,
00:54
Nevena Markova, spent about 20 years
14
54330
2000
Nevena Markov, provela je dvadeset godina
00:56
studying these profiles.
15
56330
3000
proučavajući ovakve profile.
00:59
And she published 42 articles
16
59330
2000
Objavila je 42 članka
01:01
just dedicated to the subject.
17
61330
2000
posvećenih toj temi.
01:03
Can you imagine? Day and night, thinking,
18
63330
2000
Možete li da zamislite? Dan i noć, razmišljati,
01:05
observing, the same star for 20 years
19
65330
3000
posmatrati, istu zvezdu dvadeset godina
01:08
is incredible.
20
68330
2000
je neverovatno.
01:10
But we are crazy. We do these things.
21
70330
2000
Ali mi smo ludi. Mi radimo takve stvari.
01:12
(Laughter)
22
72330
2000
(Smeh)
01:14
And I'm not that far.
23
74330
2000
Ja nisam tako daleko.
01:16
I spent about eight months working on these profiles.
24
76330
3000
Proveo sam osam meseci radeći na ovim profilima.
01:19
Because I've noticed
25
79330
2000
Primetio sam
01:21
a very small symmetry
26
81330
2000
vrlo malu simetriju
01:23
in the profile of one of the planet host stars.
27
83330
2000
u profilu jedne od zvezda koje imaju planete
01:25
And I thought, well maybe there is Lithium-6 in this star,
28
85330
4000
Mislio sam, možda je to litijum VI u ovoj zvezdi,
01:29
which is an indication that this star
29
89330
2000
što je indikator da je ova zvezda
01:31
has swallowed a planet.
30
91330
2000
progutala planetu.
01:33
Because apparently you can't have this fragile isotope
31
93330
3000
Jer navodno, ne možete imati ovaj krhki izotop
01:36
of Lithium-6 in the atmospheres of sun-like stars.
32
96330
4000
litijuma VI u atmosferi zvezda nalik Suncu.
01:40
But you have it in planets and asteroids.
33
100330
3000
Ali postoji u planetama i asteroidima.
01:43
So if you engulf planet or large number of asteroids,
34
103330
6000
Dakle, ako ste progutali planetu ili veliki broj asteroida,
01:49
you will have this Lithium-6 isotope
35
109330
3000
imaćete ovaj izotop litijuma VI
01:52
in the spectrum of the star.
36
112330
2000
u spektru zvezde.
01:54
So I invested more than eight months
37
114330
4000
Tako da sam uložio više od osam meseci
01:58
just studying the profile of this star.
38
118330
2000
samo u proučavanje profila linije litijuma ove zvezde.
02:00
And actually it's amazing,
39
120330
2000
Zapravo je fascinantno,
02:02
because I got phone calls from many reporters asking,
40
122330
2000
jer su me zvali mnogi novinari i pitali
02:04
"Have you actually seen the planet going into a star?"
41
124330
3000
"Da li ste stvarno videli kako planeta ulazi u zvezdu?"
02:07
Because they thought that if you are having a telescope,
42
127330
4000
Oni misle da ako imate teleskop,
02:11
you are an astronomer so what you are doing
43
131330
2000
vi ste astronom i to što radite je
02:13
is actually looking in a telescope.
44
133330
2000
zapravo gledanje kroz teleskop.
02:15
And you might have seen the planet going into a star.
45
135330
4000
I možda ste videli kako planeta ulazi u zvezdu.
02:19
And I was saying, "No, excuse me.
46
139330
2000
Na to sam odgovorio: "Ne, izvinite.
02:21
What I see is this one."
47
141330
2000
Ono što ja vidim je ovo."
02:23
(Laughter)
48
143330
1000
(Smeh)
02:24
It's just incredible. Because nobody understood really.
49
144330
3000
To je neverovatno. Jer niko zapravo nije razumeo.
02:27
I bet that there were very few people
50
147330
2000
Mogu se kladiti da je vrlo malo ljudi
02:29
who really understood what I'm talking about.
51
149330
3000
koji su stvarno razumeli o čemu se radi.
02:32
Because this is the indication that the planet went into the star.
52
152330
4000
Jer je ovo pokazatelj da je planeta ušla u zvezdu.
02:36
It's amazing.
53
156330
3000
To je neverovatno.
02:39
The power of spectroscopy
54
159330
2000
Moć spektroskopije
02:41
was actually realized
55
161330
2000
je zapravo ostvarena
02:43
by Pink Floyd already in 1973.
56
163330
4000
sa Pink Flojdom već 1973.
02:47
(Laughter)
57
167330
1000
(Smeh)
02:48
Because they actually said that
58
168330
3000
Oni su zapravo rekli
02:51
you can get any color you like
59
171330
2000
kako možete dobiti bilo koju boju koju želite
02:53
in a spectrum.
60
173330
2000
iz spektra.
02:55
And all you need is time and money
61
175330
2000
A sve što vam je potrebno je vreme i novac
02:57
to make your spectrograph.
62
177330
2000
kako biste napravili sopstveni spektrograf.
02:59
This is the number one high resolution,
63
179330
3000
Ovo je najbolji spektrograf visoke rezolucije,
03:02
most precise spectrograph on this planet, called HARPS,
64
182330
3000
najprecizniji spektrograf na ovoj planeti, pod nazivom HARPS,
03:05
which is actually used to detect
65
185330
2000
koji se zapravo koristi za otkrivanje
03:07
extrasolar planets and sound waves
66
187330
2000
ekstrasolarnih planeta i zvučnih talasa
03:09
in the atmospheres of stars.
67
189330
2000
u atmosferama zvezda.
03:11
How we get spectra?
68
191330
3000
Kako dobijamo spektar?
03:14
I'm sure most of you know from school physics
69
194330
3000
Verujem da većina vas to zna iz fizike iz škole
03:17
that it's basically splitting a white light
70
197330
4000
da je to u suštini prelamanje belog svetla
03:21
into colors.
71
201330
2000
na boje.
03:23
And if you have a liquid hot mass,
72
203330
3000
A ako imate tečnu vruću masu,
03:26
it will produce something which we call a continuous spectrum.
73
206330
4000
ona proizvodi, kako mi kažemo, neprekidan spektar.
03:30
A hot gas is producing emission lines only,
74
210330
3000
Vruć gas proizvodi samo emisione linije,
03:33
no continuum.
75
213330
2000
ne kontinuum.
03:35
And if you place a cool gas in front of a
76
215330
4000
Ako stavite hladan gas ispred
03:39
hot source,
77
219330
2000
vrućeg izvora,
03:41
you will see certain patterns
78
221330
2000
sigurno će te videti štablon
03:43
which we call absorption lines.
79
223330
2000
koji zovemo apsorpcione linije.
03:45
Which is used actually to identify chemical elements
80
225330
3000
Oni se, zapravo, koriste za identifikaciju hemijskih elemenata
03:48
in a cool matter,
81
228330
2000
u hladnoj materiji,
03:50
which is absorbing exactly at those frequencies.
82
230330
3000
koji budu apsorbovani na tim frekvencijama.
03:53
Now, what we can do with the spectra?
83
233330
3000
Sada, šta možemo učiniti sa tim spektrima?
03:56
We can actually study line-of-sight velocities
84
236330
3000
Mi možemo proučavati liniju radijalne brzine
03:59
of cosmic objects.
85
239330
2000
kosmičkih objekata.
04:01
And we can also study chemical composition
86
241330
3000
Možemo proučavati i hemijski sastav
04:04
and physical parameters of stars,
87
244330
2000
i fizičke parametre zvezda,
04:06
galaxies, nebulae.
88
246330
2000
galaksija, nebula.
04:08
A star is the most simple object.
89
248330
2000
Zvezda je najprostiji objekat.
04:10
In the core, we have thermonuclear reactions going on,
90
250330
4000
U središtu se odvijaju termonuklearne reakcije
04:14
creating chemical elements.
91
254330
2000
koje stvaraju hemijske elemente.
04:16
And we have a cool atmosphere.
92
256330
2000
I imamo hladnu atmosferu.
04:18
It's cool for me.
93
258330
2000
Za mene je hladna.
04:20
Cool in my terms is three or four or five thousand degrees.
94
260330
4000
U smislu da je tri ili četiri hiljade stepeni za mene hladno .
04:24
My colleagues in infra-red astronomy
95
264330
2000
Moje kolege u infracrvenoj astronomiji
04:26
call minus 200 Kelvin is cool for them.
96
266330
5000
kažu da je minus 200 Kelvina hladno za njih.
04:31
But you know, everything is relative.
97
271330
2000
Ali znate, sve je relativno.
04:33
So for me 5,000 degrees is pretty cool.
98
273330
3000
Tako da je 5.000 stepeni za mene prilično hladno.
04:36
(Laughter)
99
276330
1000
(Smeh)
04:37
This is the spectrum of the Sun --
100
277330
3000
Ovo je spektar Sunca -
04:40
24,000 spectral lines,
101
280330
3000
24.000 spektralnih linija,
04:43
and about 15 percent of these lines is not yet identified.
102
283330
4000
i oko petnaest odsto tih linija još nije identifikovano.
04:47
It is amazing. So we are in the 21st century,
103
287330
3000
To je neverovatno. Evo nas u dvadest prvom veku
04:50
and we still cannot properly understand
104
290330
2000
i još uvek ne razumemo u potpunosti
04:52
the spectrum of the sun.
105
292330
2000
spektar Sunca.
04:54
Sometimes we have to deal with
106
294330
2000
Ponekad imamo posla sa
04:56
just one tiny, weak spectral line
107
296330
3000
samo jednom tankom, slabom, spektralnom linijom
04:59
to measure the composition of that chemical element in the atmosphere.
108
299330
4000
pomoću koje merimo sastav hemijskog elementa u atmosferi.
05:03
For instance, you see the spectral line of the gold
109
303330
3000
Na primer, vidite da je spektralna linija zlata
05:06
is the only spectral line in the spectrum of the Sun.
110
306330
3000
jedina spektralna linija u spektru Sunca.
05:09
And we use this weak feature
111
309330
2000
I mi korisitmo ovu slabu odliku
05:11
to measure the composition
112
311330
2000
da bismo izmerili sastav
05:13
of gold in the atmosphere of the Sun.
113
313330
3000
zlata u atmosferi Sunca.
05:16
And now this is a work in progress.
114
316330
3000
Ovaj posao je trenutno u toku.
05:19
We have been dealing with a similarly very weak feature,
115
319330
4000
Već smo se bavili sličnim, vrlo slabim karakteristikama,
05:23
which belongs to osmium.
116
323330
2000
koje pripadaju osmiumu.
05:25
It's a heavy element produced in thermonuclear
117
325330
4000
To je težak elemenat nastao u termonuklearnim
05:29
explosions of supernovae.
118
329330
2000
eksplozijama supernove.
05:31
It's the only place where you can produce, actually, osmium.
119
331330
3000
To je jedino mesto gde zapravo možete stvoriti osmium.
05:34
Just comparing the composition of osmium
120
334330
4000
Samo uporedjujući sastav osmiuma
05:38
in one of the planet host stars,
121
338330
2000
u zvezdama oko kojih se nalaze planete
05:40
we want to understand why there is so much
122
340330
2000
želimo shvatiti zašto je toliko
05:42
of this element.
123
342330
2000
tog elementa.
05:44
Perhaps we even think that maybe
124
344330
3000
Možda mislimo da su
05:47
supernova explosions trigger formations of planets and stars.
125
347330
4000
eksplozije supernova okidači za stvaranje planeta i zvezda.
05:51
It can be an indication.
126
351330
3000
To može biti pokazatelj.
05:54
The other day, my colleague from Berkeley,
127
354330
2000
Pre neki dan, moj kolega sa Berklija,
05:56
Gibor Basri, emailed me
128
356330
2000
Gibor Basri, mi je poslao mejlom
05:58
a very interesting spectrum,
129
358330
2000
veoma zanimljiv spektar
06:00
asking me, "Can you have a look at this?"
130
360330
2000
pitajući me, "Možeš li ga pogledati?"
06:02
And I couldn't sleep, next two weeks,
131
362330
4000
I nisam mogao spavati sledeće dve nedelje.
06:06
when I saw the huge amount of oxygen
132
366330
3000
kada sam video ogromne količine kiseonika
06:09
and other elements in the spectrum of the stars.
133
369330
2000
i drugih elemenata u spektru zvezda.
06:11
I knew that there is nothing like that observed in the galaxy.
134
371330
4000
Znam da nikad tako nešto nije uočeno u galaksiji.
06:15
It was incredible. The only conclusion we could make from this
135
375330
4000
Bilo je neverovatno. Jedini zaključak koji smo mogli doneti iz toga
06:19
is clear evidence that there was a supernova explosion
136
379330
3000
jeste da je ovo jasan dokaz da se desila eksplozija supernove.
06:22
in this system, which polluted the atmosphere
137
382330
3000
u tom sistemu, koja je zagadila atmosferu
06:25
of this star.
138
385330
2000
ove zvezde.
06:27
And later a black hole was formed
139
387330
2000
A zatim je nastala crna rupa
06:29
in a binary system,
140
389330
2000
u binarnom sistemu,
06:31
which is still there with a mass of about
141
391330
2000
koji je još uvek tamo s masom od oko
06:33
five solar masses.
142
393330
2000
pet sunčevih masa.
06:35
This was considered as first evidence that actually black holes
143
395330
3000
To se smatralo prvim dokazom da crne rupe zapravo
06:38
come from supernovae explosions.
144
398330
4000
nastaju eksplozijama supernova.
06:42
My colleagues, comparing composition of chemical elements
145
402330
2000
Moje kolege, poredeći sastav hemijskih elemenata
06:44
in different galactic stars,
146
404330
2000
u različitim zvezdama u galaksijama
06:46
actually discovered alien stars in our galaxy.
147
406330
4000
su zapravo otkrile strane zvezde u našoj galaksiji.
06:50
It's amazing that you can go so far
148
410330
3000
Fascinantno je da možete tako daleko otići
06:53
simply studying the chemical composition of stars.
149
413330
4000
samo proučavajući hemijski sastav zvezda.
06:57
They actually said that one of the stars you see in the spectra
150
417330
3000
Oni su zapravo ustanovili da je jedna zvezda iz spektra
07:00
is an alien. It comes from a different galaxy.
151
420330
3000
stranac. Ona dolazi iz druge galaksije.
07:03
There is interaction of galaxies. We know this.
152
423330
3000
Postoji interakcija galaksija. Za to znamo.
07:06
And sometimes they just capture stars.
153
426330
5000
One ponekad prosto otmu zvezde.
07:11
You've heard about solar flares.
154
431330
3000
Čuli ste za solarne baklje.
07:14
We were very surprised to discover
155
434330
2000
Bili smo jako iznenađeni otkrićem
07:16
a super flare,
156
436330
2000
super baklje,
07:18
a flare which is thousands of millions of times
157
438330
4000
baklje koja je hiljadu miliona puta
07:22
more powerful than those we see in the Sun.
158
442330
2000
jača od one koju vidimo na Suncu.
07:24
In one of the binary stars in our galaxy
159
444330
3000
U jednoj binarnoj zvezdi naše galaksije
07:27
called FH Leo,
160
447330
2000
zvanoj FH Lav,
07:29
we discovered the super flare.
161
449330
2000
otkrili smo super baklju.
07:31
And later we went to study the spectral stars
162
451330
4000
Kasnije smo počeli proučavati spektralne zvezde
07:35
to see is there anything strange with these objects.
163
455330
2000
kako bismo videli ima li u njima nečeg neobičnog.
07:37
And we found that everything is normal.
164
457330
3000
I našli smo da je sve normalno.
07:40
These stars are normal like the Sun. Age, everything was normal.
165
460330
3000
Te zvezde su normalne kao Sunce. Starost, sve je bilo normalno.
07:43
So this is a mystery.
166
463330
2000
To je dakle misterija.
07:45
It's one of the mysteries we still have, super flares.
167
465330
3000
To je jedna od misterija koja i dalje nije razrešena, te super baklje.
07:48
And there are six or seven similar cases
168
468330
3000
Postoji šest ili sedam sličnih slučajeva
07:51
reported in the literature.
169
471330
2000
objavljenih u literaturi.
07:53
Now to go ahead with this,
170
473330
2000
No, da nastavimo sa temom,
07:55
we really need to understand chemical evolution of the universe.
171
475330
4000
stvarno treba da razumemo hemijsku evoluciju svemira.
07:59
It's very complicated. I don't really want you to
172
479330
2000
Jako je komplikovana. Stvarno ne želim da
08:01
try to understand what is here.
173
481330
4000
pokušate da razumete šta je ovde.
08:05
(Laughter)
174
485330
1000
(Smeh)
08:06
But it's to show you how complicated is the whole story
175
486330
3000
Ovo je da vam pokažem koliko je cela priča
08:09
of the production of chemical elements.
176
489330
2000
o proizvodnji hemijskih elemenata komplikovana.
08:11
You have two channels --
177
491330
2000
Postoje dva izvora -
08:13
the massive stars and low-mass stars --
178
493330
2000
masivne zvezde i zvezde male mase -
08:15
producing and recycling matter and chemical elements in the universe.
179
495330
3000
koje proizvode i recikliraju materiju i hemijske elemente u svemiru.
08:18
And doing this for 14 billion years,
180
498330
3000
Nakon 14 milijardi godina,
08:21
we end up with this picture,
181
501330
2000
na kraju dobijamo ovakvu sliku.
08:23
which is a very important graph,
182
503330
2000
Ovo je vrlo važan grafik,
08:25
showing relative abundances of chemical elements
183
505330
3000
koji pokazuje relativno izobilje hemijskih elemenata
08:28
in sun-like stars
184
508330
2000
u zvezdama sličnim Suncu
08:30
and in the interstellar medium.
185
510330
3000
i u međuzvezdanom mediju.
08:33
So which means that it's really impossible
186
513330
2000
Što dakle znači da je stvarno nemoguće
08:35
to find an object where you find about 10 times more sulfur than silicon,
187
515330
5000
pronaći objekte gde se može naći oko 10 puta više sumpora od silicijuma,
08:40
five times more calcium than oxygen. It's just impossible.
188
520330
4000
pet puta više kalcijuma nego kiseonika.To je jednostavno nemoguće.
08:44
And if you find one, I will say that
189
524330
2000
A ako nađete nešto takvo, reći ću vam da
08:46
this is something related to SETI,
190
526330
3000
je to nešto povezano sa SETI-jem,
08:49
because naturally you can't do it.
191
529330
4000
jer ne možete to da nadjete.
08:53
Doppler Effect is something very important
192
533330
2000
Doplerov efekat je nešto veoma važno
08:55
from fundamental physics.
193
535330
2000
za fundamentalnu fiziku.
08:57
And this is related to the change of the frequency
194
537330
2000
Ovo je povezano sa promenom frekvencije
08:59
of a moving source.
195
539330
2000
izvora koji se kreće.
09:01
The Doppler Effect is used to discover extrasolar planets.
196
541330
5000
Doplerov efekat je korišćen za otkrivanje ekstrasolarnih planeta.
09:06
The precision which we need
197
546330
2000
Neophodna preciznost
09:08
to discover a Jupiter-like planet
198
548330
2000
da bi se otkrile planete poput Jupitera
09:10
around a sun-like star
199
550330
2000
koji kruži oko zvezde poput Sunca
09:12
is something like 28.4 meters per second.
200
552330
4000
je približno 28,4 metara u sekundi.
09:16
And we need nine centimeters per second
201
556330
2000
Treba nam devet centimetara u sekundi
09:18
to detect an Earth-like planet.
202
558330
3000
da bismo otkrili planetu poput Zemlje.
09:21
This can be done with the future spectrographs.
203
561330
3000
To će se moći uraditi spektrografima u budućnosti.
09:24
I, myself, I'm actually involved in the team
204
564330
4000
Ja, lično, sam deo tima
09:28
which is developing a CODEX,
205
568330
2000
koji razvija CODEX,
09:30
high resolution, future generation spectrograph
206
570330
2000
visoko rezolucioni spektrograf nove generacije.
09:32
for the 42 meter E-ELT telescope.
207
572330
4000
za 42 metarski E-ELT teleskop.
09:36
And this is going to be an instrument
208
576330
3000
Ovo će biti instrument
09:39
to detect Earth-like planets
209
579330
2000
za otkrivanje planeta poput Zemlje
09:41
around sun-like stars.
210
581330
2000
oko zvezda nalik Suncu.
09:43
It is an amazing tool called astroseismology
211
583330
3000
To je fascinantan aparat nazvan astroseizmologija
09:46
where we can detect sound waves
212
586330
3000
pomoću kojeg možemo otkriti zvučne talase
09:49
in the atmospheres of stars.
213
589330
2000
u zvezdanim atmosferama.
09:51
This is the sound of an Alpha Cen.
214
591330
3000
Ovo je zvuk Alfa Kentaurija.
09:54
We can detect sound waves
215
594330
2000
Možemo detektovati zvučne talase
09:56
in the atmospheres of sun-like stars.
216
596330
2000
u atmosferama zvezda sličnim Suncu.
09:58
Those waves have frequencies
217
598330
3000
Ti talasi imaju frekvencije
10:01
in infrasound domain, the sound actually nobody knows, domain.
218
601330
4000
u infrazvučnom domenu, domenu koji niko ne poznaje.
10:05
Coming back to the most important question,
219
605330
2000
Vratimo se na najvažnije pitanje,
10:07
"Is there anybody out there?"
220
607330
2000
"Ima li koga tamo?"
10:09
This is closely related
221
609330
2000
To je blisko povezano
10:11
to tectonic and volcanic activity of planets.
222
611330
4000
sa tektonskim i vulkanskim aktivnostima planeta.
10:15
Connection between life
223
615330
2000
Veza izmedju života
10:17
and radioactive nuclei
224
617330
2000
i radioaktivnih jezgara
10:19
is straightforward.
225
619330
2000
je jednostavna.
10:21
No life without tectonic activity,
226
621330
3000
Nema života bez tektonske aktivnosti,
10:24
without volcanic activity.
227
624330
2000
bez vulkanske aktivnosti.
10:26
And we know very well that geothermal energy
228
626330
2000
Jako dobro znamo da geotermalna energija
10:28
is mostly produced by decay of uranium, thorium, and potassium.
229
628330
5000
uglavnom nastaje raspadanjem urana, torijuma i kalijuma.
10:33
How to measure, if we have planets
230
633330
4000
Kako to izmeriti, ako imamo planete
10:37
where the amount of those elements is small,
231
637330
4000
gde je količina tih elemenata mala,
10:41
so those planets are tectonically dead,
232
641330
3000
te su te planete tektonski mrtve,
10:44
there cannot be life.
233
644330
2000
tamo ne može biti života.
10:46
If there is too much uranium or potassium or thorium,
234
646330
3000
Ako je previše urana ili kalijuma ili torijuma,
10:49
probably, again, there would be no life.
235
649330
3000
verovatno, opet, ne bi bilo života.
10:52
Because can you imagine everything boiling?
236
652330
2000
Možete li zamisliti da sve ključa?
10:54
It's too much energy on a planet.
237
654330
2000
To je znak previše energije na planeti.
10:56
Now, we have been measuring abundance
238
656330
2000
Sada, merili smo količinu
10:58
of thorium in one of the stars with extrasolar planets.
239
658330
4000
torijuma u jednoj zvezdi sa ekstrasolarnim planetama.
11:02
It's exactly the same game. A very tiny feature.
240
662330
4000
To je potpuno ista igra. Veoma slaba osobina.
11:06
We are actually trying to measure this profile
241
666330
2000
Mi zapravo pokušavamo da izmerimo ovaj profil
11:08
and to detect thorium.
242
668330
2000
i detektujemo torijum.
11:10
It's very tough. It's very tough.
243
670330
2000
To je veoma teško. To je veoma teško.
11:12
And you have to, first you have to convince yourself.
244
672330
2000
Prvo morate ubediti sebe.
11:14
Then you have to convince your colleagues.
245
674330
2000
Onda morate ubediti svoje kolege.
11:16
And then you have to convince the whole world
246
676330
3000
A, onda morate ubediti ostatak sveta
11:19
that you have actually detected something like this
247
679330
3000
da ste zapravo detektovali nešto poput toga
11:22
in the atmosphere of an extrasolar planet
248
682330
2000
u atmosferi ekstrasolarne planete
11:24
host star somewhere in 100 parsec away from here.
249
684330
3000
koja kruži oko zvezde na sto parseka odavde.
11:27
It's really difficult.
250
687330
2000
Stvarno je teško.
11:29
But if you want to know about a life on extrasolar planets,
251
689330
5000
Ali ako želite znati nešto o životu na ekstrasolarnim planetama,
11:34
you have to do this job.
252
694330
2000
morate uraditi taj posao.
11:36
Because you have to know how much of radioactive element you have
253
696330
3000
Jer morate znati koliko imate radioaktivnih elemenata
11:39
in those systems.
254
699330
2000
u tim sistemima.
11:41
The one way to discover about aliens
255
701330
3000
Jedan način da saznate nešto o vanzemaljcima
11:44
is to tune your radio telescope and listen to the signals.
256
704330
4000
je da uključite svoj radio-teleskop i slušate signale.
11:48
If you receive something interesting,
257
708330
3000
Ako primite neke interesantne,
11:51
well that's what SETI does actually,
258
711330
2000
to je ono što SETI zapravo radi,
11:53
what SETI has been doing for many years.
259
713330
3000
što je SETI radio mnogo godina.
11:56
I think the most promising way
260
716330
2000
Mislim da je jedan od puteva sa najviše izgleda za uspeh
11:58
is to go for biomarkers.
261
718330
3000
da tražimo biomarkere.
12:01
You can see the spectrum of the Earth, this Earthshine spectrum,
262
721330
3000
Možete videti spektar Zemlje, spektar Zemljinog sjaja
12:04
and that is a very clear signal.
263
724330
3000
i to je veoma čist signal.
12:07
The slope which is coming, which we call a Red Edge,
264
727330
3000
Kriva koju dobijamo, koju zovemo Crvenom krivom,
12:10
is a detection of vegetated area.
265
730330
4000
predstavlja detektovanu površinu, pokrivenu vegetacijom.
12:14
It's amazing that we can detect vegetation
266
734330
4000
Neverovatno je da možemo detektovati vegetaciju
12:18
from a spectrum.
267
738330
2000
na osnovu spektra.
12:20
Now imagine doing this test
268
740330
2000
Sada zamislite da radite taj test
12:22
for other planets.
269
742330
3000
za druge planete.
12:25
Now very recently, very recently,
270
745330
3000
Jako nedavno, jako nedavno,
12:28
I'm talking about last six, seven, eight months,
271
748330
3000
govorim o poslednjih šest, sedam, osam meseci
12:31
water, methane, carbon dioxide
272
751330
4000
voda, metan, ugljen-dioksid
12:35
have been detected in the spectrum
273
755330
2000
su detektovani u spektru
12:37
of a planet outside the solar system.
274
757330
3000
planete van Sunčevog sistema.
12:40
It's amazing. So this is the power of spectroscopy.
275
760330
4000
To je neverovatno. To je dakle moć spektroskopije.
12:44
You can actually go and detect
276
764330
3000
Možete detektovati
12:47
and study a chemical composition of planets
277
767330
3000
i proučavati hemijski sastav planeta
12:50
far, far, far from solar system.
278
770330
3000
daleko, daleko, daleko od Sunčevog sistema.
12:53
We have to detect oxygen or ozone
279
773330
3000
Moramo detektovati kiseonik ili ozon
12:56
to make sure that we have all necessary conditions
280
776330
3000
da bismo bili sigurni da imamo sve neophodne uslove
12:59
to have life.
281
779330
4000
za život.
13:03
Cosmic miracles are something
282
783330
2000
Kosmička čuda su nešto
13:05
which can be related to SETI.
283
785330
2000
što se može povezati sa SETI-jem.
13:07
Now imagine an object, amazing object,
284
787330
2000
Sada zamislite objekat, neverovatan objekat,
13:09
or something which we cannot explain
285
789330
2000
ili nešto što ne možemo objasniti
13:11
when we just stand up and say,
286
791330
2000
kada samo ustanemo i kažemo,
13:13
"Look, we give up. Physics doesn't work."
287
793330
2000
"Pogledajte, odustajemo. Fizika ne funkcioniše."
13:15
So it's something which you can always refer to SETI and say,
288
795330
3000
To je, dakle, nešto što uvek možete povezati sa SETI-jem i reći,
13:18
"Well, somebody must be doing this, somehow."
289
798330
5000
"Pa, neko mora da radi ovo, nekako."
13:23
And with the known physics etc,
290
803330
2000
I sa poznatom fizikom itd.
13:25
it's something actually which has been pointed out
291
805330
2000
to je nešto što je naglasio
13:27
by Frank Drake,
292
807330
2000
Frenk Drejk,
13:29
many years ago, and Shklovsky.
293
809330
2000
pre mnogo godina i Šklovski,
13:31
If you see, in the spectrum of a planet host star,
294
811330
3000
Ako u spektru planete koja kruži oko zvezde
13:34
if you see strange chemical elements,
295
814330
4000
vidite strane hemijske elemente,
13:38
it can be a signal from a civilization
296
818330
3000
to može biti signal neke civilizacije
13:41
which is there and they want to signal about it.
297
821330
3000
koja je tamo i koja želi to da pokaže.
13:44
They want to actually signal their presence
298
824330
4000
Oni žele da pokažu svoju prisutnost
13:48
through these spectral lines,
299
828330
2000
preko ovih spektralnih linija,
13:50
in the spectrum of a star, in different ways.
300
830330
3000
u spektru zvezde, na različite načine.
13:53
There can be different ways doing this.
301
833330
2000
Postoji mnogo načina da se to uradi.
13:55
One is, for instance, technetium
302
835330
2000
Jedan je, na primer, tehnecijum
13:57
is a radioactive element
303
837330
2000
to je radioaktivan element
13:59
with a decay time of 4.2 million years.
304
839330
3000
sa periodom poluraspada od 4,2 miliona godina.
14:02
If you suddenly observe technetium
305
842330
3000
Ako ste slučajno posmatrali tehnecijum
14:05
in a sun-like star,
306
845330
2000
u zvezdi nalik Suncu,
14:07
you can be sure that somebody has put this
307
847330
2000
možete biti sigurni da je neko stavio taj
14:09
element in the atmosphere,
308
849330
2000
element u atmosferu,
14:11
because in a natural way it is impossible to do this.
309
851330
4000
jer prirodnim putem je to nemoguće učiniti.
14:15
Now we are reviewing the spectra of about
310
855330
3000
Mi sada pregledamo spektar nekih
14:18
300 stars with extrasolar planets.
311
858330
3000
tri stotine zvezda sa ekstrasolarnim planetama.
14:21
And we are doing this job since 2000
312
861330
4000
Mi taj posao radimo od 2000.
14:25
and it's a very heavy project.
313
865330
3000
i to je veoma težak projekat.
14:28
We have been working very hard.
314
868330
2000
Radili smo jako naporno.
14:30
And we have some interesting cases,
315
870330
4000
I imamo par zanimljivih slučajeva,
14:34
candidates, so on, things which we can't really explain.
316
874330
4000
kandidata, stvari koje ne možemo zapravo da objasnimo.
14:38
And I hope in the near future
317
878330
3000
I nadam se da ćemo u bližoj budućnosti
14:41
we can confirm this.
318
881330
2000
moći to da potvrdimo.
14:43
So the main question: "Are we alone?"
319
883330
2000
Tako da odgovor na glavno pitanje: "Da li smo sami?"
14:45
I think it will not come from UFOs.
320
885330
3000
neće doneti NLO.
14:48
It will not come from radio signals.
321
888330
4000
Neće nam ga dati radio signali.
14:52
I think it will come from a spectrum like this.
322
892330
4000
Mislim da će doći od spektra sličnog ovom.
14:56
It is the spectrum of a planet like Earth,
323
896330
5000
To je spektar planete nalik Zemlji,
15:01
showing a presence of nitrogen dioxide,
324
901330
3000
koji pokazuje prisustvo azot-dioksida,
15:04
as a clear signal of life,
325
904330
3000
kao čistog signala života,
15:07
and oxygen and ozone.
326
907330
2000
i kiseonik i ozon.
15:09
If, one day, and I think it will be
327
909330
2000
Ako, jednog dana, a verujem da hoće
15:11
within 15 years from now, or 20 years.
328
911330
3000
za 15 godina od danas ili 20 godina,
15:14
If we discover a spectrum like this
329
914330
3000
otkrijemo spektar poput ovog
15:17
we can be sure that there is life on that planet.
330
917330
2000
možemo biti sigurni da na toj planeti postoji život.
15:19
In about five years we will discover
331
919330
3000
Za jedno pet godina ćemo pronaći
15:22
planets like Earth, around sun-like stars,
332
922330
3000
planete poput Zemlje, oko zvezda poput Sunca,
15:25
the same distance as the Earth from the Sun.
333
925330
3000
na istoj udaljenosti kao udaljenosti Zemlje od Sunca.
15:28
It will take about five years.
334
928330
2000
Trebaće oko pet godina.
15:30
And then we will need another 10, 15 years
335
930330
2000
I onda će nam trebati dodatnih 10, 15 godina
15:32
with space projects
336
932330
2000
sa svemirskim projektima da bismo dobili
15:34
to get the spectra of Earth-like planets like the one I showed you.
337
934330
3000
spektre zemljolikih planeta poput onog kojeg sam vam pokazao.
15:37
And if we see the nitrogen dioxide
338
937330
2000
I ako vidimo azot dioksid
15:39
and oxygen,
339
939330
2000
i kiseonik,
15:41
I think we have the perfect E.T.
340
941330
2000
mislim da ćemo imati odličnog E.T.-a
15:43
Thank you very much.
341
943330
2000
Hvala vam mnogo.
15:45
(Applause)
342
945330
4000
(Aplauz)
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7