Somewhere, Doc Is Smiling
To the annals of the unbelievably cool, add this: a camera that can image one trillion frames per second. That’s fast enough to make a movie of light in motion.
Let me say that again: this apparatus is sufficiently precise and capable of such extreme slow motion photography that it can make a moving images of light in transit:
My favorite part of the movie itself (as opposed to the ridiculously cool tech and the gorgeous underlying science) is the choice of target, amidst all that ferociously exact equipment. Yup. Coke does rule our world.
From the MIT press release linked above, here’s a basic explanation of what’s going on:
The system relies on a recent technology called a streak camera, deployed in a totally unexpected way. The aperture of the streak camera is a narrow slit. Particles of light — photons — enter the camera through the slit and pass through an electric field that deflects them in a direction perpendicular to the slit. Because the electric field is changing very rapidly, it deflects late-arriving photons more than it does early-arriving ones.The image produced by the camera is thus two-dimensional, but only one of the dimensions — the one corresponding to the direction of the slit — is spatial. The other dimension, corresponding to the degree of deflection, is time. The image thus represents the time of arrival of photons passing through a one-dimensional slice of space…
...But it’s a serious drawback in a video camera. To produce their super-slow-mo videos, Velten, Media Lab Associate Professor Ramesh Raskar and Moungi Bawendi, the Lester Wolfe Professor of Chemistry, must perform the same experiment — such as passing a light pulse through a bottle — over and over, continually repositioning the streak camera to gradually build up a two-dimensional image. Synchronizing the camera and the laser that generates the pulse, so that the timing of every exposure is the same, requires a battery of sophisticated optical equipment and exquisite mechanical control. It takes only a nanosecond — a billionth of a second — for light to scatter through a bottle, but it takes about an hour to collect all the data necessary for the final video. For that reason, Raskar calls the new system “the world’s slowest fastest camera.”
Bonus trillion fps eye-candy videos here.
And yup, somewhere, Doc Edgerton is one happy camper.
Now that is cool. It is early here, but I am having trouble seeing how the photons are deflected by an electric field. Perhaps I should follow the links.
December 13th, 2011 at 9:27 am
When I was a larval froshling at MIT, one of my classes had a recitation section up in what used to be Strobe Alley. It was great, because all of the classrooms were essentially repurposed labs, and there were all sorts of strange pieces of equipment just quietly sitting on shelves for us to gawk at. Oh, and the photos lining the hallway were pretty neat as well…
December 13th, 2011 at 9:32 am
I wish there were some images. I cannot look at the video at work.
December 13th, 2011 at 9:33 am
@Jerzy Russian: I agree that ‘photons deflected by electric field’ doesn’t make much sense.
Also, note that the concept of the streak camera has been around for a while:
http://en.wikipedia.org/wiki/Photo_finish
The ability to observe a pulse of light propagating in ‘real’ time is quite neat and maybe even scientifically useful. It means you can observe non-linear dispersive (or pulse-sharpening) effects directly. Or, e.g., you can measure variation in index of refraction of some complex medium by just observing how a pulse is deformed as it travels. Or, e.g., you can look at non-isotropic propagation in birefringent materials. Yowza!
December 13th, 2011 at 9:37 am
The big science news for today, though, is that CERN has evidence that we’ve finally, after about 50 years, have managed to see the Higgs Boson. It’s a roughly 3-sigma signal above background, so it’s not quite at the level of claiming to have unequivocally discovered the thing (another several months of data at LHC starting in March should improve the statistics enough to say ‘yes’ or ‘no’ for sure), but the odds are pretty good.
December 13th, 2011 at 9:39 am
Pretty cool.
The sad thing is I would just use it to take cat pics.
December 13th, 2011 at 9:43 am
Even using this technology I bet the NFL can still fuck up a call in the replay booth.
December 13th, 2011 at 9:46 am
Damn, that set me up to have a good mood all day! Now my secretary fears the world is ending soon since I am no longer grumpy.
That is remarkably cool to watch the light passing through the bottle and know it is not just sci-fi SpecFX.
December 13th, 2011 at 9:46 am
@dmsilev: Absolutely. But everyone’s going to cover that.
Perhaps we should think of this as an amuse bouche before the main course?
December 13th, 2011 at 9:47 am
The videos are pretty neat, although the music drives me bats.
I also sat there for a minute thinking of what it would’ve cost me to shoot 1 second of 16mm footage at that fps rate.
December 13th, 2011 at 9:48 am
“amidst all that ferociously exact equipment” and then he pans the frame by simply moving the mirror with his hand. So very exacting, but nonetheless cool.
December 13th, 2011 at 9:56 am
@noodler: For actually running the experiment, that mirror is undoubtedly connected to a piezoelectric actuator or some other very precise motion device. That’s awfully slow, so for the video I’m sure they just disconnected the actuator and panned the thing by hand. And then probably spent a hour or two realigning the mirror.
December 13th, 2011 at 10:00 am
Funny, the headline made me think of Doc Brown from Back to the Future. This is just the kind of thing you want if you’re going to be running tests on a flux capacitor.
December 13th, 2011 at 10:11 am
You know what would be nice? To see a white English-speaking person doing some of this work.
I’m all for immigration – I’m an immigrant myself – but it’s sad that Americans (and basically all white English-speaking people) are more interested in sports and other trivial things while the rest of the world passes us by, using, ironically, our universities.
But hey! The problem with schools here is not lack of science, marth, and arts education. It’s lack of PRAYER and alternatives to evolution!
December 13th, 2011 at 10:15 am
New tag? Coke.R.E.A.M?
Very neat camera. I think they need to shoot floppy puppy ears next.
December 13th, 2011 at 10:17 am
“Particles of light — photons — enter the camera through the slit and pass through an electric field that deflects them in a direction perpendicular to the slit.”
I want to repeat that I also do not understand this. Photons
have no charge. How can an electric field deflect them.
Neutrons have no charge, but do have a dipole moment, so I can see that possibility. But photons? They follow shortest paths in spacetime. So do electric fields bend spacetime the way gravity does? I did not know that (if it is the case). I do not remember any contribution of electric fields in the big tensors in General Relativity.
December 13th, 2011 at 10:20 am
That’s cool. Very, very cool.
December 13th, 2011 at 10:35 am
@catclub: From Wiki:
So, whoever wrote that press release was a bit confused about how these cameras work.
December 13th, 2011 at 10:36 am
@dmsilev: thanks!
Electrons, ... photons, what’s the big diff?
December 13th, 2011 at 10:48 am
Sure. But can it do drop frame?
December 13th, 2011 at 10:55 am
Wow that is so cool. Maybe I’m a bit dense but I had to watch the video a couple times to actually see what they meant by capturing the photon.
December 13th, 2011 at 11:18 am
@catclub: A photon is taking a vacation and is checking in at the airline baggage counter. The clerk asks if he has any bags to check and the photon says “No, I’m traveling light”.
A hydrogen molecule is seen rummaging through drawers, looking under the couch cushions, etc., her significant other asks her what’s wrong. The hydrogen molecule says, I think I’ve lost an electron. The SO asks, are you sure and the hydrogen molecule says “I’m positive”.
Some pico-humor for a pico-event
December 13th, 2011 at 11:22 am
@Michael D.:
Race or language should have nothing to do with this. It’s a SPECIES issue. I’m glad that a HUMAN figured this out. Those damn Turians are always saying how better they are than humans, but we’ll show them!!
December 13th, 2011 at 11:28 am
@dmsilev:
Thanks for looking this up. This makes much more sense.
December 13th, 2011 at 11:41 am
I have one of these machines in the shed behind my trailer.
December 13th, 2011 at 12:50 pm
My relatively gigantic dslr maxes out at a measly 5fps @ 1/8000 sec. I bow in the general direction of this gizmo, even though I barely understand what they’re up to.
December 13th, 2011 at 1:15 pm
I never thought I’d say this, but I am suddenly truly and sincerely interested in watching paint dry.
December 13th, 2011 at 2:10 pm
For the first time in my life, I am sincerely and passionately interested in watching paint dry.
December 13th, 2011 at 2:16 pm
Thank you Tom, makes me wonder if they had really pushed alternative energy sources back in the eighty’s, how we would be receiving our electricity now?
December 13th, 2011 at 2:19 pm
And my slow work connection made me think my first comment was lost to the ether…sorry.
December 13th, 2011 at 2:26 pm
@Michael D.:
To be perfectly honest, America has always had to import a great deal of its best scientific and engineering talent. Einstein, Goedel, Von Neumann, Von Braun… the list goes on and on.
I think the American culture and education system just is extremely poor at cultivating the scientific mind. The current Republican war on science wouldn’t be possible in a culture that values rational thinking and analysis.
December 13th, 2011 at 2:52 pm
I am confused. The concept of capturing how light travels through space has no meaning. If the camera sees anything (and it seems to in the videos), it is because the photons have already reached it. It can’t really capture light on its way through space. So, what are we seeing in these videos?
December 13th, 2011 at 4:30 pm