How to take a picture of a black hole | Katie Bouman

3,361,362 views ・ 2017-04-28

TED


Dvaput kliknite na engleske titlove ispod za reprodukciju videozapisa.

Prevoditelj: Katarina Mikjel Recezent: Sanda L
00:13
In the movie "Interstellar,"
0
13436
1860
U filmu „Interstellar”
00:15
we get an up-close look at a supermassive black hole.
1
15320
3327
možemo izbliza vidjeti supermasivnu crnu rupu.
00:18
Set against a backdrop of bright gas,
2
18671
2143
Na pozadini koju stvara zagrijani plin
00:20
the black hole's massive gravitational pull
3
20838
2118
ogromna gravitacijska sila te crne rupe
00:22
bends light into a ring.
4
22980
1435
zakreće svjetlost u prsten.
00:24
However, this isn't a real photograph,
5
24439
2109
Međutim, to nije stvarna fotografija,
00:26
but a computer graphic rendering --
6
26572
1786
već računalno-grafički prikaz –
00:28
an artistic interpretation of what a black hole might look like.
7
28382
3390
umjetnička interpretacija mogućeg izgleda crne rupe.
00:32
A hundred years ago,
8
32401
1166
Prije sto godina
00:33
Albert Einstein first published his theory of general relativity.
9
33591
3601
Albert Einstein objavio je svoju teoriju opće relativnosti.
00:37
In the years since then,
10
37216
1439
U godinama koje su uslijedile
00:38
scientists have provided a lot of evidence in support of it.
11
38679
2973
znanstvenici su pronašli mnogo dokaza u prilog toj teoriji.
00:41
But one thing predicted from this theory, black holes,
12
41676
3084
No jedna stvar koju ta teorija predviđa, crne rupe,
00:44
still have not been directly observed.
13
44784
2350
još nije izravno opažena.
00:47
Although we have some idea as to what a black hole might look like,
14
47158
3206
Iako imamo predodžbe o tome kako bi crna rupa mogla izgledati,
00:50
we've never actually taken a picture of one before.
15
50388
2779
nikad je zapravo nismo uspjeli fotografirati.
00:53
However, you might be surprised to know that that may soon change.
16
53191
4279
Ipak, možda ćete se iznenaditi kad čujete da bi se to uskoro moglo promijeniti.
00:57
We may be seeing our first picture of a black hole in the next couple years.
17
57494
4164
U sljedećih par godina mogli bismo vidjeti prvu fotografiju crne rupe.
01:01
Getting this first picture will come down to an international team of scientists,
18
61682
3958
Tu prvu fotografiju dobit ćemo
zahvaljujući međunarodnom timu znanstvenika,
01:05
an Earth-sized telescope
19
65664
1567
teleskopu veličine Zemlje
01:07
and an algorithm that puts together the final picture.
20
67255
2832
i algoritmu koji će složiti konačnu sliku.
01:10
Although I won't be able to show you a real picture of a black hole today,
21
70111
3528
Premda vam danas još ne mogu pokazati stvarnu fotografiju crne rupe,
01:13
I'd like to give you a brief glimpse into the effort involved
22
73663
2911
htjela bih vam ukratko predstaviti napore uložene
01:16
in getting that first picture.
23
76598
1613
u dobivanje te prve fotografije.
01:19
My name is Katie Bouman,
24
79477
1437
Zovem se Katie Bouman
01:20
and I'm a PhD student at MIT.
25
80938
2566
i doktorandica sam na MIT-u.
01:23
I do research in a computer science lab
26
83528
2027
Istraživačica sam u laboratoriju računalnih znanosti,
01:25
that works on making computers see through images and video.
27
85579
3298
gdje razvijamo računalni vid s pomoću slika i videozapisa.
01:28
But although I'm not an astronomer,
28
88901
2162
No iako nisam astronom,
danas bih vam htjela pokazati
01:31
today I'd like to show you
29
91087
1285
01:32
how I've been able to contribute to this exciting project.
30
92396
2903
kako sam uspjela doprinijeti tom uzbudljivom projektu.
01:35
If you go out past the bright city lights tonight,
31
95323
2831
Odmaknete li se večeras od jarkih gradskih svjetala,
01:38
you may just be lucky enough to see a stunning view
32
98178
2436
možda budete imali sreće pa ugledate zapanjujući prizor
01:40
of the Milky Way Galaxy.
33
100638
1493
galaktike Mliječne staze.
01:42
And if you could zoom past millions of stars,
34
102155
2462
Kad biste mogli prozujati pored milijuna zvijezda
01:44
26,000 light-years toward the heart of the spiraling Milky Way,
35
104641
3755
26 000 svjetlosnih godina prema središtu spiralne Mliječne staze,
01:48
we'd eventually reach a cluster of stars right at the center.
36
108420
3521
naposljetku biste stigli do skupine zvijezda u samom središtu.
01:51
Peering past all the galactic dust with infrared telescopes,
37
111965
3206
Gledajući infracrvenim teleskopima kroz galaktičku prašinu
01:55
astronomers have watched these stars for over 16 years.
38
115195
3867
astronomi su promatrali te zvijezde više od 16 godina.
01:59
But it's what they don't see that is the most spectacular.
39
119086
3589
Međutim, najspektakularnije je zapravo ono što ne vide.
02:02
These stars seem to orbit an invisible object.
40
122699
3066
Čini se kao da te zvijezde kruže oko nevidljiva objekta.
02:05
By tracking the paths of these stars,
41
125789
2323
Prateći putanje tih zvijezda
02:08
astronomers have concluded
42
128136
1294
astronomi su zaključili da je
02:09
that the only thing small and heavy enough to cause this motion
43
129454
3129
jedina stvar koja je dovoljno mala i teška da prouzroči takvo kretanje
02:12
is a supermassive black hole --
44
132607
1968
supermasivna crna rupa –
02:14
an object so dense that it sucks up anything that ventures too close --
45
134599
4178
objekt toliko gust da usiše sve u svojoj blizini –
02:18
even light.
46
138801
1494
čak i svjetlost.
02:20
But what happens if we were to zoom in even further?
47
140319
3061
No što se događa ako se još više približimo?
02:23
Is it possible to see something that, by definition, is impossible to see?
48
143404
4733
Je li moguće vidjeti nešto što je, u pravilu, nemoguće vidjeti?
02:28
Well, it turns out that if we were to zoom in at radio wavelengths,
49
148719
3244
Pa, čini se da ako uvećamo sliku s pomoću radiovalova,
02:31
we'd expect to see a ring of light
50
151987
1682
trebali bismo vidjeti svjetlosni prsten
02:33
caused by the gravitational lensing of hot plasma
51
153693
2411
koji nastaje zbog utjecaja gravitacijskih leća na vruću plazmu
02:36
zipping around the black hole.
52
156128
1829
što brzo kruži oko crne rupe.
02:37
In other words,
53
157981
1160
Drugim riječima,
02:39
the black hole casts a shadow on this backdrop of bright material,
54
159165
3171
crna rupa baca sjenu na tu svjetlosnu pozadinu
02:42
carving out a sphere of darkness.
55
162360
1842
oblikujući kuglu tame.
02:44
This bright ring reveals the black hole's event horizon,
56
164226
3339
Taj svijetli prsten otkriva obzor događaja crne rupe,
02:47
where the gravitational pull becomes so great
57
167589
2400
gdje je gravitacijska sila toliko snažna
da joj čak ni svjetlost ne može pobjeći.
02:50
that not even light can escape.
58
170013
1626
02:51
Einstein's equations predict the size and shape of this ring,
59
171663
2859
Einsteinove jednadžbe predviđaju veličinu i oblik tog prstena,
02:54
so taking a picture of it wouldn't only be really cool,
60
174546
3208
tako da njegova fotografija ne bi samo bila fora,
02:57
it would also help to verify that these equations hold
61
177778
2618
nego bi nam pomogla i da provjerimo vrijede li te jednadžbe
03:00
in the extreme conditions around the black hole.
62
180420
2466
u ekstremnim uvjetima oko crne rupe.
03:02
However, this black hole is so far away from us,
63
182910
2558
Međutim, ta crna rupa toliko je udaljena od nas
03:05
that from Earth, this ring appears incredibly small --
64
185492
3098
da se sa Zemlje taj prsten doima nevjerojatno malim –
03:08
the same size to us as an orange on the surface of the moon.
65
188614
3590
tako bi nam nekako izgledala naranča na Mjesecu.
03:12
That makes taking a picture of it extremely difficult.
66
192758
2824
Zbog toga ga je vrlo teško fotografirati.
03:16
Why is that?
67
196645
1302
Zašto je tomu tako?
03:18
Well, it all comes down to a simple equation.
68
198512
3188
Pa, sve se svodi na jednostavnu jednadžbu.
03:21
Due to a phenomenon called diffraction,
69
201724
2416
Zbog pojave poznate kao difrakcija,
03:24
there are fundamental limits
70
204164
1355
postoje temeljna ograničenja
03:25
to the smallest objects that we can possibly see.
71
205543
2670
koja određuju koliki su najmanji vidljivi predmeti.
03:28
This governing equation says that in order to see smaller and smaller,
72
208789
3672
Prema toj glavnoj jednadžbi, da bismo vidjeli sve manje i manje stvari,
03:32
we need to make our telescope bigger and bigger.
73
212485
2587
trebaju nam sve veći i veći teleskopi.
03:35
But even with the most powerful optical telescopes here on Earth,
74
215096
3069
No čak ni najsnažniji optički teleskopi na Zemlji
03:38
we can't even get close to the resolution necessary
75
218189
2419
nemaju rezoluciju koja nam je potrebna
03:40
to image on the surface of the moon.
76
220632
2198
kako bismo fotografirali objekt na površini Mjeseca.
03:42
In fact, here I show one of the highest resolution images ever taken
77
222854
3617
Ustvari, ovo je jedna od fotografija s dosad najvećom rezolucijom
na kojoj je Mjesec, fotografiran sa Zemlje.
03:46
of the moon from Earth.
78
226495
1397
03:47
It contains roughly 13,000 pixels,
79
227916
2557
Sadržava oko 13 000 piksela,
03:50
and yet each pixel would contain over 1.5 million oranges.
80
230497
4050
a u svaki od njih „stane” preko 1,5 milijuna naranči.
03:55
So how big of a telescope do we need
81
235396
1972
Koliki bi dakle trebao biti teleskop
03:57
in order to see an orange on the surface of the moon
82
237392
2765
kako bismo vidjeli naranču na površini Mjeseca,
04:00
and, by extension, our black hole?
83
240181
2214
a tako i našu crnu rupu?
04:02
Well, it turns out that by crunching the numbers,
84
242419
2340
Pa, jednostavan matematički izračun pokazuje
04:04
you can easily calculate that we would need a telescope
85
244783
2610
da nam je potreban teleskop
veličine cijele Zemlje.
04:07
the size of the entire Earth.
86
247417
1393
04:08
(Laughter)
87
248834
1024
(Smijeh)
04:09
If we could build this Earth-sized telescope,
88
249882
2119
Kad bismo mogli izgraditi teleskop veličine Zemlje,
uspjeli bismo tek nazreti taj karakterističan svjetlosni prsten
04:12
we could just start to make out that distinctive ring of light
89
252025
2925
04:14
indicative of the black hole's event horizon.
90
254974
2183
koji označava obzor događaja crne rupe.
Iako se na toj slici ne bi vidjeli svi detalji koji su vidljivi
04:17
Although this picture wouldn't contain all the detail we see
91
257181
2918
na računalno-grafičkom prikazu,
04:20
in computer graphic renderings,
92
260123
1506
04:21
it would allow us to safely get our first glimpse
93
261653
2299
svakako bi nam dala prvi uvid
04:23
of the immediate environment around a black hole.
94
263976
2487
u neposredno okruženje crne rupe.
04:26
However, as you can imagine,
95
266487
1613
Međutim, kao što možete i zamisliti,
04:28
building a single-dish telescope the size of the Earth is impossible.
96
268124
3624
nemoguće je izgraditi jedinstveni teleskop veličine Zemlje.
04:31
But in the famous words of Mick Jagger,
97
271772
1887
No, slavnim riječima Micka Jaggera,
04:33
"You can't always get what you want,
98
273683
1791
„ne možeš uvijek dobiti ono što želiš,
04:35
but if you try sometimes, you just might find
99
275498
2187
no pokušaš li ponekad, možda shvatiš
04:37
you get what you need."
100
277709
1215
da si dobio ono što ti treba.”
04:38
And by connecting telescopes from around the world,
101
278948
2464
Povezivanjem teleskopa diljem svijeta,
04:41
an international collaboration called the Event Horizon Telescope
102
281436
3538
međunarodni projekt Event Horizon Telescope
04:44
is creating a computational telescope the size of the Earth,
103
284998
3109
stvara računalni teleskop veličine Zemlje,
koji će moći zabilježiti strukturu
04:48
capable of resolving structure
104
288131
1537
04:49
on the scale of a black hole's event horizon.
105
289692
2199
razmjera obzora događaja crne rupe.
04:51
This network of telescopes is scheduled to take its very first picture
106
291915
3387
Ta mreža teleskopa trebala bi prvi put fotografirati
crnu rupu sljedeće godine.
04:55
of a black hole next year.
107
295326
1815
04:57
Each telescope in the worldwide network works together.
108
297165
3338
Svi teleskopi u toj svjetskoj mreži rade zajedno.
05:00
Linked through the precise timing of atomic clocks,
109
300527
2712
Povezani preciznim mjerenjem vremena s pomoću atomskih satova,
05:03
teams of researchers at each of the sites freeze light
110
303263
2657
timovi istraživača na svakoj lokaciji zamrzavaju svjetlost
05:05
by collecting thousands of terabytes of data.
111
305944
2962
prikupljajući tisuće terabajta podataka.
05:08
This data is then processed in a lab right here in Massachusetts.
112
308930
5017
Ti se podaci potom obrađuju u laboratoriju ovdje u Massachusettsu.
05:13
So how does this even work?
113
313971
1794
Kako to zapravo funkcionira?
05:15
Remember if we want to see the black hole in the center of our galaxy,
114
315789
3403
Sjećate li se da, ako želimo vidjeti crnu rupu u središtu naše galaktike,
trebamo izgraditi nemoguće velik teleskop veličine Zemlje?
05:19
we need to build this impossibly large Earth-sized telescope?
115
319216
2982
05:22
For just a second, let's pretend we could build
116
322222
2232
Zamislimo na trenutak da je moguće izgraditi
05:24
a telescope the size of the Earth.
117
324478
1842
teleskop veličine Zemlje.
05:26
This would be a little bit like turning the Earth
118
326344
2455
To bi pomalo nalikovalo pretvaranju Zemlje
05:28
into a giant spinning disco ball.
119
328823
1747
u divovsku disko-kuglu koja se vrti.
05:30
Each individual mirror would collect light
120
330594
2200
Svako pojedino zrcalo skupljalo bi svjetlost,
05:32
that we could then combine together to make a picture.
121
332818
2597
koju bismo zatim spojili u jednu sliku.
05:35
However, now let's say we remove most of those mirrors
122
335439
2661
Međutim, recimo da uklonimo većinu tih zrcala
05:38
so only a few remained.
123
338124
1972
i da ih ostane tek nekolicina.
05:40
We could still try to combine this information together,
124
340120
2877
I dalje bismo mogli kombinirati podatke koje su prikupili,
05:43
but now there are a lot of holes.
125
343021
1993
no u tom bi slučaju ostalo puno praznina.
05:45
These remaining mirrors represent the locations where we have telescopes.
126
345038
4373
Ta preostala zrcala predstavljaju lokacije na koje smo postavili teleskope.
05:49
This is an incredibly small number of measurements to make a picture from.
127
349435
4079
To nam daje nevjerojatno malen broj podataka za izradu slike.
05:53
But although we only collect light at a few telescope locations,
128
353538
3838
No iako skupljamo svjetlost na samo nekoliko lokacija s teleskopima,
05:57
as the Earth rotates, we get to see other new measurements.
129
357400
3423
budući da se Zemlja okreće, dobivamo i druge, nove podatke.
06:00
In other words, as the disco ball spins, those mirrors change locations
130
360847
3819
Drugim riječima, kako se disko-kugla vrti, ta zrcala mijenjaju lokacije
06:04
and we get to observe different parts of the image.
131
364690
2899
i možemo vidjeti različite dijelove slike.
06:07
The imaging algorithms we develop fill in the missing gaps of the disco ball
132
367613
4018
Algoritmi za stvaranje slike koje smo razvili popunjavaju praznine na disko-kugli
06:11
in order to reconstruct the underlying black hole image.
133
371655
3033
kako bismo rekonstruirali osnovnu sliku crne rupe.
06:14
If we had telescopes located everywhere on the globe --
134
374712
2636
Kad bismo rasporedili teleskope po cijelom planetu,
06:17
in other words, the entire disco ball --
135
377372
1941
drugim riječima, po cijeloj disko-kugli –
06:19
this would be trivial.
136
379337
1284
bio bi to čas posla.
06:20
However, we only see a few samples, and for that reason,
137
380645
3322
Međutim, vidimo svega nekoliko uzoraka i zbog toga
06:23
there are an infinite number of possible images
138
383991
2388
postoji beskonačan broj mogućih slika
06:26
that are perfectly consistent with our telescope measurements.
139
386403
2964
koje su posve u skladu s podacima naših teleskopa.
06:29
However, not all images are created equal.
140
389391
3016
Međutim, nisu sve slike jednake.
06:32
Some of those images look more like what we think of as images than others.
141
392849
4458
Neke od njih više nalikuju onome što obično smatramo slikama od drugih.
06:37
And so, my role in helping to take the first image of a black hole
142
397331
3222
Moja je uloga u stvaranju prve fotografije crne rupe
06:40
is to design algorithms that find the most reasonable image
143
400577
2932
dizajnirati algoritme koji će pronaći najsmisleniju sliku
06:43
that also fits the telescope measurements.
144
403533
2222
koja je u skladu s podacima teleskopa.
06:46
Just as a forensic sketch artist uses limited descriptions
145
406727
3942
Baš kao što se forenzički crtač koristi manjkavim opisima
06:50
to piece together a picture using their knowledge of face structure,
146
410693
3514
kako bi, uz pomoć svojeg poznavanja strukture lica, sastavio sliku,
06:54
the imaging algorithms I develop use our limited telescope data
147
414231
3315
algoritmi za dobivanje slike koje sam razvila
koriste se manjkavim podacima naših teleskopa
06:57
to guide us to a picture that also looks like stuff in our universe.
148
417570
4322
kako bi nas doveli do slike koja izgleda kao nešto iz našeg svemira.
07:01
Using these algorithms, we're able to piece together pictures
149
421916
3651
S pomoću tih algoritama možemo sastaviti slike
07:05
from this sparse, noisy data.
150
425591
2180
od tih malobrojnih, nejasnih podataka.
07:07
So here I show a sample reconstruction done using simulated data,
151
427795
4529
Ovo je primjer rekonstrukcije napravljene s pomoću simuliranih podataka
07:12
when we pretend to point our telescopes
152
432348
1933
kad zamislimo da smo usmjerili teleskope
07:14
to the black hole in the center of our galaxy.
153
434305
2585
prema crnoj rupi u središtu naše galaktike.
07:16
Although this is just a simulation, reconstruction such as this give us hope
154
436914
4455
Premda je to samo simulacija,
rekonstrukcije kao što je ova pružaju nam nadu
07:21
that we'll soon be able to reliably take the first image of a black hole
155
441393
3453
da ćemo uskoro moći dobiti prvu pouzdanu sliku crne rupe
07:24
and from it, determine the size of its ring.
156
444870
2595
i s pomoću te slike odrediti veličinu njezina prstena.
07:28
Although I'd love to go on about all the details of this algorithm,
157
448118
3199
Iako bih rado još razglabala o tom algoritmu,
07:31
luckily for you, I don't have the time.
158
451341
2174
srećom po vas, nemam vremena.
07:33
But I'd still like to give you a brief idea
159
453539
2001
No ipak bih vam htjela ukratko dočarati
07:35
of how we define what our universe looks like,
160
455564
2302
kako određujemo izgled našeg svemira
07:37
and how we use this to reconstruct and verify our results.
161
457890
4466
i kako uz pomoć toga rekonstruiramo i provjeravamo svoje rezultate.
07:42
Since there are an infinite number of possible images
162
462380
2496
Budući da postoji beskonačno mnogo mogućih slika
07:44
that perfectly explain our telescope measurements,
163
464900
2365
koje su potpuno u skladu s podacima naših teleskopa,
07:47
we have to choose between them in some way.
164
467289
2605
moramo ih nekako filtrirati.
07:49
We do this by ranking the images
165
469918
1838
To činimo rangiranjem slika
07:51
based upon how likely they are to be the black hole image,
166
471780
2834
na temelju toga koliko je vjerojatno da su upravo one slike crne rupe
07:54
and then choosing the one that's most likely.
167
474638
2482
i zatim biramo onu za koju je ta vjerojatnost najveća.
07:57
So what do I mean by this exactly?
168
477144
2195
Što točno želim reći?
07:59
Let's say we were trying to make a model
169
479862
1978
Recimo da pokušavamo napraviti model
08:01
that told us how likely an image were to appear on Facebook.
170
481864
3183
koji bi nam rekao kolika je vjerojatnost da se neka slika pojavi na Facebooku.
08:05
We'd probably want the model to say
171
485071
1701
Vjerojatno bismo htjeli da nam model kaže
08:06
it's pretty unlikely that someone would post this noise image on the left,
172
486796
3557
kako je malo vjerojatno da netko objavi sliku sa šumovima lijevo,
08:10
and pretty likely that someone would post a selfie
173
490377
2419
a vrlo vjerojatno da netko objavi selfie
08:12
like this one on the right.
174
492820
1334
poput ovoga desno.
08:14
The image in the middle is blurry,
175
494178
1639
Slika u sredini je mutna,
08:15
so even though it's more likely we'd see it on Facebook
176
495841
2639
pa iako bismo je prije mogli vidjeti na Facebooku
08:18
compared to the noise image,
177
498504
1360
nego sliku sa šumovima,
08:19
it's probably less likely we'd see it compared to the selfie.
178
499888
2960
vjerojatno su manje šanse da ćemo vidjeti nju nego onaj selfie.
08:22
But when it comes to images from the black hole,
179
502872
2290
Međutim, kad je riječ o slikama crne rupe,
pred nama je prava zagonetka: nikad je dosad nismo vidjeli.
08:25
we're posed with a real conundrum: we've never seen a black hole before.
180
505186
3502
08:28
In that case, what is a likely black hole image,
181
508712
2291
Koja je vjerojatna slika crne rupe u tom slučaju
08:31
and what should we assume about the structure of black holes?
182
511027
2938
i što da pretpostavimo o strukturi crnih rupa?
08:33
We could try to use images from simulations we've done,
183
513989
2632
Mogli bismo pokušati iskoristiti slike iz simulacija koje smo napravili,
08:36
like the image of the black hole from "Interstellar,"
184
516645
2530
poput slike crne rupe iz filma „Interstellar”,
no učinimo li to, mogli bi nastati ozbiljni problemi.
08:39
but if we did this, it could cause some serious problems.
185
519199
2938
08:42
What would happen if Einstein's theories didn't hold?
186
522161
3380
Što ako bi se pokazalo da Einsteinove teorije ne drže vodu?
08:45
We'd still want to reconstruct an accurate picture of what was going on.
187
525565
3961
I dalje bismo željeli točno rekonstruirati što se događa.
08:49
If we bake Einstein's equations too much into our algorithms,
188
529550
3371
Ako svoje algoritme previše baziramo na Einsteinovim teorijama,
08:52
we'll just end up seeing what we expect to see.
189
532945
2755
na kraju ćemo vidjeti samo ono što i očekujemo da ćemo vidjeti.
08:55
In other words, we want to leave the option open
190
535724
2276
Drugim riječima, želimo ostaviti otvorenom mogućnost
da se u središtu naše galaktike zapravo nalazi divovski slon.
08:58
for there being a giant elephant at the center of our galaxy.
191
538024
2923
09:00
(Laughter)
192
540971
1057
(Smijeh)
09:02
Different types of images have very distinct features.
193
542052
2989
Različite vrste slika imaju vrlo različite osobine.
09:05
We can easily tell the difference between black hole simulation images
194
545065
3548
Možemo lako razlikovati simulacijske slike crne rupe
09:08
and images we take every day here on Earth.
195
548637
2276
od onih koje svakodnevno snimamo ovdje na Zemlji.
09:10
We need a way to tell our algorithms what images look like
196
550937
3104
Treba nam način na koji bismo algoritmima rekli kako slike izgledaju,
09:14
without imposing one type of image's features too much.
197
554065
3249
a da istovremeno previše ne namećemo osobine jedne vrste slika.
09:17
One way we can try to get around this
198
557865
1893
Jedan od načina na koji bismo to mogli riješiti
09:19
is by imposing the features of different kinds of images
199
559782
3062
jest da ubacimo osobine različitih vrsta slika
09:22
and seeing how the type of image we assume affects our reconstructions.
200
562868
4130
i vidimo kako pretpostavljena vrsta slike utječe na naše rekonstrukcije.
09:27
If all images' types produce a very similar-looking image,
201
567712
3491
Ako sve vrste slika dovode do vrlo slične slike,
09:31
then we can start to become more confident
202
571227
2057
možemo biti sigurniji
09:33
that the image assumptions we're making are not biasing this picture that much.
203
573308
4173
da naše pretpostavke ne idu previše u prilog jednoj slici.
09:37
This is a little bit like giving the same description
204
577505
2990
To je donekle kao da date isti opis
09:40
to three different sketch artists from all around the world.
205
580519
2996
trima različitim crtačima diljem svijeta.
09:43
If they all produce a very similar-looking face,
206
583539
2860
Nacrtaju li svi vrlo slična lica,
09:46
then we can start to become confident
207
586423
1793
možemo biti sigurni
09:48
that they're not imposing their own cultural biases on the drawings.
208
588240
3616
da njihovi crteži nisu previše uvjetovani njihovom kulturom.
09:51
One way we can try to impose different image features
209
591880
3315
Jedan od načina na koji možemo pokušati nametnuti različite osobine slike
09:55
is by using pieces of existing images.
210
595219
2441
jest korištenjem dijelova postojećih slika.
09:58
So we take a large collection of images,
211
598214
2160
Veliku zbirku slika
10:00
and we break them down into their little image patches.
212
600398
2718
rastavimo na male komadiće.
10:03
We then can treat each image patch a little bit like pieces of a puzzle.
213
603140
4285
Svaki od tih komadića pomalo nalikuje dijelu slagalice.
10:07
And we use commonly seen puzzle pieces to piece together an image
214
607449
4278
Često viđenim dijelovima slagalice koristimo se kako bismo složili sliku
10:11
that also fits our telescope measurements.
215
611751
2452
koja je u skladu s podacima naših teleskopa.
Različite vrste slika imaju vrlo karakteristične skupove dijelova slagalice.
10:15
Different types of images have very distinctive sets of puzzle pieces.
216
615040
3743
10:18
So what happens when we take the same data
217
618807
2806
A što se događa kad s istim podacima,
10:21
but we use different sets of puzzle pieces to reconstruct the image?
218
621637
4130
ali s različitim skupovima dijelova slagalice pokušamo rekonstruirati sliku?
10:25
Let's first start with black hole image simulation puzzle pieces.
219
625791
4766
Započnimo s dijelovima slagalice za simulaciju slike crne rupe.
10:30
OK, this looks reasonable.
220
630581
1591
U redu, ovo izgleda vjerojatno.
10:32
This looks like what we expect a black hole to look like.
221
632196
2694
Izgleda onako kako očekujemo da crna rupa izgleda.
10:34
But did we just get it
222
634914
1193
No jesmo li dobili takvu sliku
10:36
because we just fed it little pieces of black hole simulation images?
223
636131
3314
jer smo uključili djeliće slika simulacije crne rupe?
10:39
Let's try another set of puzzle pieces
224
639469
1880
Pokušajmo s drugim skupom dijelova slagalice,
10:41
from astronomical, non-black hole objects.
225
641373
2509
koji potječe od astronomskih objekata koji nisu povezani s crnom rupom.
10:44
OK, we get a similar-looking image.
226
644914
2126
U redu, dobivamo vrlo sličnu sliku.
Što je s dijelovima koji potječu od svakodnevnih slika,
10:47
And then how about pieces from everyday images,
227
647064
2236
10:49
like the images you take with your own personal camera?
228
649324
2785
kao što su one koje snimate vlastitim fotoaparatom?
10:53
Great, we see the same image.
229
653312
2115
Odlično, dobivamo istu sliku.
10:55
When we get the same image from all different sets of puzzle pieces,
230
655451
3366
Kad dobijemo istu sliku od svih raznih skupova dijelova slagalice,
10:58
then we can start to become more confident
231
658841
2046
možemo biti sigurniji
11:00
that the image assumptions we're making
232
660911
1966
da naše pretpostavke o slici
11:02
aren't biasing the final image we get too much.
233
662901
2921
ne utječu pretjerano na konačan rezultat.
11:05
Another thing we can do is take the same set of puzzle pieces,
234
665846
3253
Usto, možemo i isti skup dijelova slagalice,
11:09
such as the ones derived from everyday images,
235
669123
2489
kao što su oni koji potječu od svakodnevnih slika,
11:11
and use them to reconstruct many different kinds of source images.
236
671636
3600
upotrijebiti za rekonstrukciju raznih izvornih slika.
11:15
So in our simulations,
237
675260
1271
Dakle, u našim simulacijama
11:16
we pretend a black hole looks like astronomical non-black hole objects,
238
676555
3775
pretvaramo se da crna rupa izgleda kao astronomski objekti koji nisu crna rupa
11:20
as well as everyday images like the elephant in the center of our galaxy.
239
680354
3849
te kao svakodnevne slike, kao što je slon u središtu naše galaktike.
11:24
When the results of our algorithms on the bottom look very similar
240
684227
3168
Kad rezultati naših algoritama na dnu izgledaju vrlo slično
11:27
to the simulation's truth image on top,
241
687419
2096
pravoj slici simulacije na vrhu,
11:29
then we can start to become more confident in our algorithms.
242
689539
3346
možemo se početi pouzdavati u te algoritme.
11:32
And I really want to emphasize here
243
692909
1867
Ono što stvarno želim naglasiti jest
11:34
that all of these pictures were created
244
694800
1934
da su sve ove slike nastale
11:36
by piecing together little pieces of everyday photographs,
245
696758
2936
slaganjem djelića svakodnevnih fotografija,
11:39
like you'd take with your own personal camera.
246
699718
2215
kao što su one koje biste fotografirali vlastitim fotoaparatom.
11:41
So an image of a black hole we've never seen before
247
701957
3276
Dakle, sliku crne rupe koju nikad nismo vidjeli
11:45
may eventually be created by piecing together pictures we see all the time
248
705257
3943
naposljetku ćemo možda dobiti od slika koje stalno viđamo –
11:49
of people, buildings, trees, cats and dogs.
249
709224
2745
slika ljudi, zgrada, stabala, mačaka i pasa.
11:51
Imaging ideas like this will make it possible for us
250
711993
2645
Takve ideje o dobivanju slika omogućit će nam
11:54
to take our very first pictures of a black hole,
251
714662
2619
da prvi put fotografiramo crnu rupu
11:57
and hopefully, verify those famous theories
252
717305
2447
i, nadajmo se, potvrditi slavne teorije
11:59
on which scientists rely on a daily basis.
253
719776
2421
na koje se znanstvenici svakodnevno oslanjaju.
12:02
But of course, getting imaging ideas like this working
254
722221
2608
No, naravno, takve se ideje
12:04
would never have been possible without the amazing team of researchers
255
724853
3322
ne bi mogle ostvariti bez nevjerojatnog tima istraživača
12:08
that I have the privilege to work with.
256
728199
1887
s kojima imam čast raditi.
I dalje me zadivljuje
12:10
It still amazes me
257
730110
1163
to što bi, iako sam počela rad na ovom projektu bez predznanja o astrofizici,
12:11
that although I began this project with no background in astrophysics,
258
731297
3351
12:14
what we have achieved through this unique collaboration
259
734672
2619
ono što smo postigli tom jedinstvenom suradnjom
moglo rezultirati prvim slikama crne rupe.
12:17
could result in the very first images of a black hole.
260
737315
2759
12:20
But big projects like the Event Horizon Telescope
261
740098
2698
No veliki projekti kao što je Event Horizon Telescope
12:22
are successful due to all the interdisciplinary expertise
262
742820
2814
uspješni su zahvaljujući interdisciplinarnoj stručnosti
12:25
different people bring to the table.
263
745658
1790
različitih sudionika.
12:27
We're a melting pot of astronomers,
264
747472
1706
Mi smo raznolika skupina astronoma,
12:29
physicists, mathematicians and engineers.
265
749202
2232
fizičara, matematičara i inženjera.
12:31
This is what will make it soon possible
266
751458
2554
To je ono što će uskoro omogućiti
12:34
to achieve something once thought impossible.
267
754036
2853
da postignemo nešto što se nekoć smatralo nemogućim.
12:36
I'd like to encourage all of you to go out
268
756913
2256
Htjela bih vas sve ohrabriti da odavde iziđete
12:39
and help push the boundaries of science,
269
759193
2096
spremni pomicati granice znanosti,
12:41
even if it may at first seem as mysterious to you as a black hole.
270
761313
3901
i onda kada se suočite s nečim tako misterioznim kao što je crna rupa.
12:45
Thank you.
271
765238
1174
Hvala vam.
12:46
(Applause)
272
766436
2397
(Pljesak)
O ovoj web stranici

Ova stranica će vas upoznati s YouTube videozapisima koji su korisni za učenje engleskog jezika. Vidjet ćete lekcije engleskog koje vode vrhunski profesori iz cijelog svijeta. Dvaput kliknite na engleske titlove prikazane na svakoj video stranici da biste reproducirali video s tog mjesta. Titlovi se pomiču sinkronizirano s reprodukcijom videozapisa. Ako imate bilo kakvih komentara ili zahtjeva, obratite nam se putem ovog obrasca za kontakt.

https://forms.gle/WvT1wiN1qDtmnspy7