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.
Edgerton博士用這張子彈擊穿蘋果的照片 激起了我們的敬佩和好奇, 這張照片的曝光時間只有一百萬分之一秒。 但現在,五十年後,我們可以在快一百萬倍, 也就是不僅在一百萬分之一秒, 或者十億分之一秒, 而是在萬億分之一秒見捕捉到世界。
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.
現在我給你展示一種新型照相技術, 叫做飛秒成像, 這是一種技術太快以至於 它能捕捉到光的運動。 所以用這個技術,我們可以制造 能看到光路拐角的照相機, 能看到視野之外 或者不用X光就能透視我們身體的照相機, 這種相機挑戰了我們對於照相機的定義。
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?
現在,如果我用一個激光筆, 並且在萬億分之一秒內開關一次—— 也就是幾飛秒—— 我就會制造一些光子, 這些光子僅僅是幾毫米寬, 並且這些光子,像子彈一樣, 會以光速前進, 也就是比子彈速度高一百萬倍。 現在,如果你把這個子彈,這些光子 打入這個瓶子裏, 這些光子會怎麽樣撞擊瓶子? 光在慢動作下會是什麽樣?
[Light in Slow Motion ... 10 Billion x Slow]
Now, the whole event --
現在,著整個事情—— (鼓掌)
(Applause)
(鼓掌)
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.
現在,請記住,這整個事情 其實是在一納秒內發生的 ——也就是光走的時間—— 但現在我再把這個錄像放慢一百萬倍 讓你看到運動中的光。
(Laughter)
但可口可樂可沒有資助這個實驗。 (笑聲)
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.
現在,在這裏有很多事會發生, 所以讓我一件一件的展示。 現在,光束進入瓶子,也就是我們的子彈, 穿過瓶子, 並且在內部散射開來。 一些光流了出來,到了桌子上, 所以你開始看到這些波紋。 許多光子最終到達了瓶蓋處 並且向四周散去。 你能看到,這裏是一個空氣泡, 它在裏面反彈。 同時,波紋也到了桌子上, 並且因爲在頂部的反射, 你能看到在瓶子底部,幾幀之後, 反射彙聚了。
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?
現在,如果你用普通的子彈 走同樣的路程,平且放慢視頻, 同樣是一百萬倍,你知道 你需要等多久來看到這個全過程嗎?
(Laughter)
A day, a week? Actually, a whole year. It'll be a very boring movie --
一天,一周?實際上,是一年。 這當然會很無聊 (笑聲)
(Laughter)
of a slow, ordinary bullet in motion.
一個慢的,普通的子彈運動錄像。
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.
但一些靜物照相又如何呢? 你可以看到波紋再次在桌子上展開, 背景是紅番茄和牆。 這就像在水池裏扔一塊石頭。
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.
我想,這就是自然如何繪制的紅番茄, 一飛秒一飛秒, 但當然我們眼睛看到的是整體的結合。 但如果你在看一下這個紅番茄, 你就會注意到,當光在紅番茄上走過時, 它一直在閃耀。它並沒有變暗。 爲什麽?因爲紅番茄熟了, 並且光在紅番茄內部反射, 在幾萬億分之一秒後出來。 所以,在未來,當飛米成像相機 在你的手機裏的時候, 你就可以去超市,
(Laughter)
不用摸就能檢查一下水果是否熟了。
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.
那麽,麻省理工學院的團隊是怎麽做出這個相機的呢? 現在,作爲攝影師,你知道, 如果你想要短時曝光,你只有一點點光, 但我們需要比最短的曝光時間 快一百萬倍, 所以你幾乎得不到任何光。 所以,我們做的是, 把這些光子送進去,並重複百萬多次, 每次都以極好的同步錄像, 然後從數十億位元的數據中, 我們“編織”起來一幅圖, 而這幅圖就是你們之前看到的。
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.
並且我們把所有的原始數據到算進去時, 進行很有趣的處理。 現在,超人能飛。 一些其他英雄能隱身, 但想象一個未來的超人: 他能看到拐角後面的東西。 這原理是我們可以把一些光打到門上, 這些光會反射進入房間, 一些會返回到門上, 然後進入照相機, 這樣我們就可以利用這些光的反射。
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.
這可不是科幻片。我們真正的做出來了。 在左邊,你看到了我們的飛秒成像相機。 在牆後面有一個人體模型, 我們將進行光反射。
So after our paper was published in Nature Communications, it was highlighted by Nature.com, and they created this animation.
所以,在我們的論文發表 在《自然》上後, 它被推薦到自然的官網上,
(Music)
然後他們創造了這個動畫。
[A laser pulse is fired]
(音樂)
(Music)
我們將要發射這些光子彈,
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.
它們將要撞擊這個牆, 並且因爲這束光 會散射到各個方向, 一些會最終打到我們的隱藏的假人上, 並且會繼續散射, 知道這個門也會反射 一些光, 而一部分光會最終 返回到相機裏,但最有趣的是, 它們會在略微不同的時間到達。
(Music)
(音樂)
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.
而且因爲我們有一個可以運行如此之快的相機, 也就是我們的飛秒相機,這個相機就有一些特別的能力。 它有很好的時間分辨率, 並且可以以光速捕捉世界。 所以這樣,我們不僅知道相機到門的距離, 同時知道到隱藏物品的距離, 但我們不知道哪個點
(Music)
對應哪個距離。
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?
(音樂) 通過用激光,我們能記錄一個原始的照片, 也就是你們在屏幕上看到的這個,好像沒什麽意義, 但然後我們會拍很多照片, 很多很多,放到一起, 然後分析光的反射, 現在我們能看到那個隱藏的物體了嗎? 我們能立體的看懂嗎?
So this is our reconstruction.
這就是我們的模型重建。 (音樂)
(Music)
(音樂)
(Applause)
(音樂) (掌聲)
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.
現在距離我們在將這科技應用到生活中 還有一些路要走, 但在未來,我們可以把這個技術放到車裏, 這樣車就能防止碰撞,因爲他們能看到拐角, 或者我們可以搜尋幸存者, 因爲我們能看到在窗戶上反射的光, 或者我們可以建造透視儀, 來看到身體裏的情況, 我們甚至可以透視心臟。 但當然,由於各種組織和血液的幹擾, 這回相當困難, 所以我們呼籲科學家來真正重視飛秒成像, 把這個技術作爲一種 解決下一代健康問題的新模型。
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.
現在,就像Edgerton博士,一個科學家, 科學變成了藝術,一種高速攝影藝術, 而且我意識到我們每次 大量資料 不僅是科學成像, 而是一種新的計算性攝影, 這種技術蘊含了時間延遲和彩色編碼, 我們看這些波紋。 記住,這些波紋之間的時間 僅僅是幾個萬億分之一秒。
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?
但有些有趣的事正在發生, 當你看到這些蓋子下的波紋時, 他們正在離我們遠去。 但這些波紋應該向我們移動。 發生了什麽?
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.
結果是,因爲我們在以接近光速 來錄這些東西, 我們有一些奇怪的現象,
(Laughter)
愛因斯坦會相當高興看到這些圖片。
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.
事件發生的順序 在相機裏有時候被反轉了, 所以通過對應時間和空間的扭曲, 我們可以修正這個扭曲。
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 --
所以不管是看到拐角, 還是爲下一代製造健康影像, 還是增加新的可視化, 自從我們的發明, 我們就已經把所有的資料和細節放到了我們的網上, 並且我們希望,這個DIY,這個創意的研究團體, 可以告訴我們
(Laughter)
我們不應該再迷上高像素 —(笑聲)—
and start focusing on the next dimension in imaging. It's about time.
而開始關注成像技術的另一個維度。 時間差不多了。謝謝。 (掌聲)
Thank you.
(Applause)
(掌聲)