Doc Edgerton inspired us with awe and curiosity with this photo of a bullet piercing through an apple, and exposure just a millionth of a second. But now, 50 years later, we can go a million times faster and see the world not at a million or a billion, but one trillion frames per second.
Doc Edgerton je v nas vzbudil čudenje in radovednost s to sliko izstrelka, ki prodira skozi jabolko pri osvetlitvi milijoninke sekunde. 50 let kasneje smo lahko milijonkrat hitrejši in sveta ne vidimo le pri milijonu ali milijardi, temveč pri bilijonu sličic na sekundo.
I present to you a new type of photography, femto-photography, a new imaging technique so fast that it can create slow motion videos of light in motion. And with that, we can create cameras that can look around corners, beyond line of sight, or see inside our body without an x-ray, and really challenge what we mean by a camera.
Predstavljam vam novo vrsto fotografije, femto-fotografijo, ki je tako hitra tehnika snemanja, da lahko ustvari počasne posnetke gibanja svetlobe. Izdelamo lahko kamere, ki lahko pogledajo okrog vogala, izven zorne linije in brez rentgenskih žarkov vidijo v notranjost telesa ter izrazu kamera dajejo nov pomen.
Now if I take a laser pointer and turn it on and off in one trillionth of a second -- which is several femtoseconds -- I'll create a packet of photons barely a millimeter wide. And that packet of photons, that bullet, will travel at the speed of light, and again, a million times faster than an ordinary bullet. Now, if you take that bullet and take this packet of photons and fire into this bottle, how will those photons shatter into this bottle? How does light look in slow motion?
Če vzamem lasersko kazalko in jo vključim za bilijoninko sekunde, kar je nekaj femtosekund, ustvarim paket fotonov, ki je širok zgolj milimeter. Ta paket fotonov oziroma izstrelek bo potoval s svetlobno hitrostjo, milijonkrat hitreje kot navaden izstrelek. Če ta izstrelek oziroma paket fotonov izstrelim v plastenko – kako se bodo fotoni razpršili v plastenki? Kako je videti svetloba v počasnem posnetku?
[Light in Slow Motion ... 10 Billion x Slow]
Now, the whole event --
Celoten dogodek – (Aplavz)
(Applause)
(Aplavz)
Now remember, the whole event is effectively taking place in less than a nanosecond -- that's how much time it takes for light to travel. But I'm slowing down in this video by a factor of 10 billion, so you can see the light in motion.
Torej, celoten dogodek se odvije v manj kot nanosekundi, kar je čas, ki ga svetloba potrebuje za to pot, vendar je posnetek upočasnjen z večkratnikom 10 milijard, da lahko vidite svetlobo v gibanju.
(Laughter)
Coca-Cola ni sponzor teh raziskav. (Smeh)
But Coca-Cola did not sponsor this research.
(Laughter)
Now, there's a lot going on in this movie, so let me break this down and show you what's going on. So the pulse enters the bottle, our bullet, with a packet of photons that start traveling through and that start scattering inside. Some of the light leaks, goes on the table, and you start seeing these ripples of waves. Many of the photons eventually reach the cap and then they explode in various directions. As you can see, there's a bubble of air and it's bouncing around inside. Meanwhile, the ripples are traveling on the table, and because of the reflections at the top, you see at the back of the bottle, after several frames, the reflections are focused.
Na tem posnetku se veliko dogaja, zato bom opisal korake in vam povedal, za kaj gre. Utrip svetlobe, naš izstrelek, vstopi v plastenko kot paket fotonov, ki pričnejo svojo pot skozi in ki se začnejo v notranjosti sipati. Nekaj svetlobe uide ven in gre na mizo, zato opazite to valovanje. Kar nekaj fotonov končno doseže pokrovček in jih tam raznese v različne smeri. Vidite lahko zračni mehurček in kako se v njem odbija. Medtem valovanje potuje po mizi, zaradi odboja na vrhu pa se na dnu plastenke po nekaj sličicah odboji osredotočijo.
Now, if you take an ordinary bullet and let it go the same distance and slow down the video -- again, by a factor of 10 billion -- do you know how long you'll have to sit here to watch that movie?
Če bi vzeli navaden izstrelek, ga spustili čez enako razdaljo in posnetek upočasnili prav tako s faktorjem 10 milijard – ali veste, kako dolgo bi sedeli tu, da bi si ga ogledali?
(Laughter)
A day, a week? Actually, a whole year. It'll be a very boring movie --
En dan, en teden? Trajalo bi celo leto. To bi bil zelo dolgočasen posnetek (Smeh)
(Laughter)
of a slow, ordinary bullet in motion.
počasnega, navadnega izstrelka v gibanju.
And what about some still-life photography? You can watch the ripples, again, washing over the table, the tomato and the wall in the back. It's like throwing a stone in a pond of water.
Kaj pa fotografija tihožitja? Spet lahko vidite valovanje, ki preplavi mizo, paradižnik in steno v ozadju. Kot bi v vodo vrgli kamen.
I thought: this is how nature paints a photo, one femto frame at a time, but of course our eye sees an integral composite. But if you look at this tomato one more time, you will notice, as the light washes over the tomato, it continues to glow. It doesn't become dark. Why is that? Because the tomato is actually ripe, and the light is bouncing around inside the tomato, and it comes out after several trillionths of a second. So in the future, when this femto-camera is in your camera phone, you might be able to go to a supermarket and check if the fruit is ripe without actually touching it.
Narava na tak način naslika fotografijo, eno femto sličico za drugo, a naše oko vidi celovito sestavljeno sliko. Če še enkrat pogledate paradižnik, boste videli, da potem, ko ga preplavi svetloba, še naprej sije. Ne zatemni se. Zakaj? Paradižnik je dejansko zrel in svetloba se znotraj njega odbija, ven pa pride po nekaj bilijoninkah sekunde. Ko boste v prihodnosti to femto-kamero imeli v svojem mobilnem telefonu, boste lahko v trgovini
(Laughter)
preverjali zrelost sadežev ne da bi se jih dotaknili.
So how did my team at MIT create this camera? Now, as photographers, you know, if you take a short exposure photo, you get very little light. But we're going to go a billion times faster than your shortest exposure, so you're going to get hardly any light. So what we do is we send that bullet -- that packet of photons -- millions of times, and record again and again with very clever synchronization, and from the gigabytes of data, we computationally weave together to create those femto-videos I showed you.
In kako smo z ekipo na MIT izdelali to kamero? Fotograf ve, da pri kratki osvetlitvi dobimo le malo svetlobe, mi pa snemamo pri milijardokrat večji hitrosti kot je najkrajša osvetlitev, tako da dobimo komaj kaj svetlobe. Naredimo tako, da pošljemo izstrelke, te pakete fotonov, milijonkrat in jih posnamemo znova in znova, jih domiselno uskladimo in potem iz gigabajtov podatkov, ki jih računsko stkemo skupaj, ustvarimo te femto-posnetke.
And we can take all that raw data and treat it in very interesting ways. So, Superman can fly. Some other heroes can become invisible. But what about a new power for a future superhero: To see around corners. The idea is that we could shine some light on the door, it's going to bounce, go inside the room, some of that is going to reflect back on the door, and then back to the camera. And we could exploit these multiple bounces of light.
Surove podatke zberemo in jih obdelamo na zanimive načine. Superman lahko poleti. Nekateri drugi junaki lahko postanejo nevidni, morda pa bi kak drug super junak lahko gledal okrog vogalov? Zamisel je v tem, da posvetimo na vrata. Svetloba se bo odbila v sobo, nekaj se je bo odbilo nazaj na vrata, in potem nazaj h kameri, tako da bi lahko izkoristili te večkratne odboje.
And it's not science fiction. We have actually built it. On the left, you see our femto-camera. There's a mannequin hidden behind a wall, and we're going to bounce light off the door.
To ni znanstvena fantastika, to smo res naredili. Na levi vidite femto-kamero. Za steno je skrita lutka, z vrati pa bomo odbili svetlobo.
So after our paper was published in Nature Communications, it was highlighted by Nature.com, and they created this animation.
Ko je bil naš članek objavljen v reviji Nature Communications, je nanj opozorila stran Nature.com,
(Music)
kjer so izdelali naslednjo animacijo.
[A laser pulse is fired]
(Glasba)
(Music)
Izstrelili bomo izstrelke svetlobe,
Ramesh Raskar: We're going to fire those bullets of light, and they're going to hit this wall, and because of the packet of the photons, they will scatter in all the directions, and some of them will reach our hidden mannequin, which in turn will again scatter that light, and again in turn, the door will reflect some of that scattered light. And a tiny fraction of the photons will actually come back to the camera, but most interestingly, they will all arrive at a slightly different time slot.
ki se bodo zadeli ob to steno, in ker gre za pakete fotonov, se bodo ti razpršili v vse smeri, nekaj jih bo doseglo našo skrito lutko, ki bo spet razpršila svetlobo, in potem bodo vrata odbila nekaj te razpršene svetlobe, majcen del fotonov pa se bo dejansko vrnil k kameri, vendar – še posebej zanimivo – bodo prispeli v različnih časovnih intervalih.
(Music)
(Glasba)
And because we have a camera that can run so fast -- our femto-camera -- it has some unique abilities. It has very good time resolution, and it can look at the world at the speed of light. And this way, we know the distances, of course to the door, but also to the hidden objects, but we don't know which point corresponds to which distance.
Ker je naša femto-kamera tako hitra, ima nekaj edinstvenih sposobnosti. Ima izredno dobro časovno ločljivost in svet lahko vidi pri hitrosti svetlobe. Poznamo razdaljo do vrat in do skritih predmetov, ne vemo pa, katera točka ustreza
(Music)
kateri razdalji.
By shining one laser, we can record one raw photo, which, if you look on the screen, doesn't really make any sense. But then we will take a lot of such pictures, dozens of such pictures, put them together, and try to analyze the multiple bounces of light, and from that, can we see the hidden object? Can we see it in full 3D?
(Glasba) Ko posvetimo z enim laserjem, lahko naredimo en surov posnetek, ki ni videti prav zgovoren. Ampak naredimo več takih posnetkov, na ducate, in jih združimo ter analiziramo večkratne odboje svetlobe, iz tega pa – ali lahko vidimo skriti predmet? Ga lahko vidimo v treh razsežnostih?
So this is our reconstruction.
Takole smo ga rekonstruirali. (Glasba)
(Music)
(Glasba)
(Applause)
(Glasba) (Aplavz)
Now, we have some ways to go before we take this outside the lab on the road, but in the future, we could create cars that avoid collisions with what's around the bend. Or we can look for survivors in hazardous conditions by looking at light reflected through open windows. Or we can build endoscopes that can see deep inside the body around occluders, and also for cardioscopes. But of course, because of tissue and blood, this is quite challenging, so this is really a call for scientists to start thinking about femto-photography as really a new imaging modality to solve the next generation of health-imaging problems.
Še dolga je pot, preden bomo lahko šli iz laboratorija v dejansko okolje, a v prihodnosti bi lahko izdelali avte, ki bi se izogibali trkom s predmeti izza ovinka, in v nevarnih okoliščinah bi lahko iskali preživele, s tem, ko bi opazovali svetlobo, odbito prek odprtih oken, lahko pa bi izdelali endoskope, ki bi lahko gledali globoko v telo okrog zapor, ali kardioskope. Seveda bi bilo to zaradi tkiv in krvi velik izziv, tako da je to poziv znanstvenikom, naj začnejo razmišljati o femtofotografiji kot novem načinu snemanja, ki bo rešitev za naslednjo generacijo težav pri zdravstvenih posnetkih.
Now, like Doc Edgerton, a scientist himself, science became art -- an art of ultra-fast photography. And I realized that all the gigabytes of data that we're collecting every time, are not just for scientific imaging. But we can also do a new form of computational photography, with time-lapse and color coding. And we look at those ripples. Remember: The time between each of those ripples is only a few trillionths of a second.
Enako kot Doc Edgerton, ki je bil tudi znanstvenik, gledam na znanost ultra-hitre fotografije kot na umetnost in sem spoznal, da vsi ti gigabajti podatkov, ki jih vsakič zberemo, niso le znanstveni posnetki, ampak lahko izdelamo novo vrsto računske fotografije s posnetki v časovnih intervalih in z barvnim označevanjem ter z njimi pogledamo valovanje. Ne pozabite, da je časovna razlika med vsakim valom le nekaj bilijonink sekunde.
But there's also something funny going on here. When you look at the ripples under the cap, the ripples are moving away from us. The ripples should be moving towards us. What's going on here?
Pri tem pa se dogaja še nekaj čudnega. Če pogledate valove pod pokrovčkom, vidite, da se oddaljujejo. Morali pa bi se približevati. Kaj se dogaja?
It turns out, because we're recording nearly at the speed of light, we have strange effects, and Einstein would have loved to see this picture.
Zato, ker snemamo s skoraj svetlobno hitrostjo, dobimo nenavadne učinke –
(Laughter)
Einstein bi najbrž z veseljem videl to sliko.
The order at which events take place in the world appears in the camera sometimes in reversed order. So by applying the corresponding space and time warp, we can correct for this distortion.
Zaporedje, po katerem se odvijajo dogodki, so v kameri v navidezno obrnjenem zaporedju, ko pa prostor in čas ustrezno upognemo, lahko popačenje popravimo.
So whether it's for photography around corners, or creating the next generation of health imaging, or creating new visualizations, since our invention, we have open-sourced all the data and details on our website, and our hope is that the DIY, the creative and the research communities will show us that we should stop obsessing about the megapixels in cameras --
Za vse – fotografijo izza vogala, zdravstvene posnetke naslednje generacije, izdelavo novih upodobitev – smo od odkritja naprej nudili odprto-kodni dostop do vseh podatkov na našem spletnem mestu, in upamo, da bodo domači mojstri, ustvarjalci in raziskovalci vsem pokazali, naj se nehamo gnati za
(Laughter)
megapiksli v kamerah (Smeh)
and start focusing on the next dimension in imaging. It's about time.
in naj se obrnemo k naslednji razsežnosti posnetkov. Nastopil je čas. (Aplavz)
Thank you.
(Applause)
(Aplavz)