ฝัง
- เผยแพร่เมื่อ 25 ก.ค. 2012
- www.ted.com Ramesh Raskar presents femto-photography, a new type of imaging so fast it visualizes the world one trillion frames per second, so detailed it shows light itself in motion. This technology may someday be used to build cameras that can look "around" corners or see inside the body without X-rays.
TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes. Featured speakers have included Al Gore on climate change, Philippe Starck on design, Jill Bolte Taylor on observing her own stroke, Nicholas Negroponte on One Laptop per Child, Jane Goodall on chimpanzees, Bill Gates on malaria and mosquitoes, Pattie Maes on the "Sixth Sense" wearable tech, and "Lost" producer JJ Abrams on the allure of mystery. TED stands for Technology, Entertainment, Design, and TEDTalks cover these topics as well as science, business, development and the arts. Closed captions and translated subtitles in a variety of languages are now available on TED.com, at www.ted.com/translate
If you have questions or comments about this or other TED videos, please go to support.ted.com - วิทยาศาสตร์และเทคโนโลยี
It took TH-cam 7 years to recommend me this??? This is one of the greatest thing a human can see in their whole lifetime!!!
Love how everybody is being shocked of the "speed" this video of "catching the light" reached its viewers.
It really isn’t… This is all smoke and mirrors because the camera is only creating computer-generated images by information that they are pre-programming into it… There’s a reason this is seven years old and we haven’t heard about it...it’s because it’s all bullshit pseudoscience
@@davesims7917 "This is all smoke and mirrors because the camera is only creating computer-generated images by information that they are pre-programming into it… " That's what all cameras do. Why does this completely normal factor of all cameras make this pseudoscience?
Same here
8 to me
As a PC gamer I can confirm that if you play under a trillion frames per second, you're a filthy casual
2 trillion get on my level bruh!
Dont start telling me you cant notice a difference between this and 140fps, i clearly do, i just know i do.
But the human eye can only see 10fps xdddddd
Will Hedley U fkng skrub, 1v1 me
i would like to see a solar eclipse with that camera
7 years and this is still the coolest TED talk
this along with 6th sensse technology by Pranav Mistry TED Video
They didn't use a laser but white light. The light would have dispersed when it hit the bottle and then water. The shape of the 'bullet' of light is also wrong and should have the same cross section from front to back. The shape of the 'bullet' of light seems to change along the length of the bottle indicating that the separate photons have different light speeds? How is it possible to switch the source light on and off in such a short time? (approx 10e-11s)? Its amazing every comment here praises the experiment without question. In my opinion the experiment was contrived and animated. Coolest TED talk? More like coolest TED lies!
@@johnnym6700 even if they had used laser light i think its still a very big achievement because laser light also travel with speed of white light . This techology can be used in many things .
@@arunsharma-ze1sl Sorry not possible. Fake experiment. Did you not read what I said? What technology?
@@johnnym6700 ,TED is a very reputed platform this guy is from MIT i dont think they will do fake stuff . The detail technical aspects you are talking about people from quantum mechanics better comment about it not i may be you are something missing .
I told my dad that if the sun went dark we wouldn't know it for 8 minutes. His response was, "why did you have to tell me that".
Science is a passion for me. This is a revelation. We see light with our eyes as being instantaneous but it's not. It's one of the fundamental things people should know.
Nobody thinks you are a genius because of this by the way
Who the hell was his audience? These people just saw the speed of light, the fastest speed there is in our world. And they saw it slowed down enough to see it move in SLOW MOTION! Do they not understand what they just saw? The audience at the iPhone 5 was more excited than these people. This is easily one of the most incredible advances in science! The ability to see the speed of light... it's pretty fucking awesome people, get hype!
+Second Zeta Without light, there is no angry birds
+Slevin Reviews This isn't my first time watching, but the first time I've looked at the comments and I agree with you. I was just amazed that people weren't shouting and cheering. As another commenter said, why didn't people stop me in the streets about this stuff. This is AMAZING stuff.
Oscar Conroy Maybe they aren't aware of this technological breakthrough. Being able to slow down the speed of light, enough to observe and study it, will provide science/engineering a whole new field to to draw inventions from. It's the fastest moving thing in existence.
As brilliant and amazing as this is, it's a computer animation based on a composition of repeated exposures, not a recording of a live action event.
Slevin Reviews when I am amazed I usually don't say a word for minutes because I'm left speechless. I would not be surprised if none of them said a word.
A well deserved standing ovation. We can hardly imagine what we may discover by observing light in slow motion.
And I still can’t get 60 frames on a dam PlayStation
@@thejam7129 you can't get it on Xbox either
@@atartup pc master race
@@thejam7129 go to the doctor you idiot
PC is also same.
If you do the same scene over and over again, and merge your frames, you can get 60 frames per second :) That is exactly how this is done.
TED: imaging a trillion frames per second
Console players: but...but the eyes can only see 60 frames per second
I believe the human eye can see up to 1000fps but gamers are just sad
@@TheAviationistKhizr Literally nobody asked you. What's sad is posting videos of roller coasters on youtube.
@@jaggerjdm9787 No what's sad is posting animations and using bandicam screen recorder with a massive f watermark. Also no one asked you to use TH-cam, no one asked you to watch this video, no one asked you to look in the comments and no one asked you to reply to my comment. So if you've got a problem then just leave moron.
@@TheAviationistKhizr I second this
@@pallav8725 appreciate it dude 😉
This is the most incredible thing I've ever seen! But why aren't they redoing the double-slit experiment? I would love to see wave-particle duality in action. From what I can tell here, it's less a duality and more... splashy.
And why am I just now hearing about this? This is from 2012! People should have been stopping me in the street to tell me about this.
Me too! The duality! Count my vote here!
Jason Flaherty I agree it would be interesting to see, but if i was a betting man i'd say that we would still be performing a measurement, and the result would be much the same as with any other measurement. Particle behavior
+Jason Flaherty I so much wish Vsauce doing a double slit experiment with this incredible camera.
+Jason Flaherty SAME HERE! WHY AM I SEEING THIS JUST NOW???
+Mephistolomaniac You're absolutely right, and I think it's important that people understand this point. *If you know what slit the light is going through, expect particle behavior. It's when you don't know where the light is that nature is at her cheekiest.*
this just blew my mind and it happened 6 years ago.... how has nobody told me this
Edit: oh yeah I have no friends
I always try to make friends but rarely am able to make them !
Hmmm...we can be friends
Me too ,
When it first got published, I posted an article about this (video inlay) on Scheißbook.
Result: 1 like
I published a photo of a really nice drink with tapas food.
Result: 68 likes
I published a good profile shot of myself which doesn't matter.
Result: 113 likes
But even that is not the punchline.
These people are all eligible to vote.
@@franknada8235 And breed. And drive.
I also saw this put into use by archaeologists to scan an entire area of a abandoned village. What they found was absolutely amazing. just with a flicker of light, they were able to map the entire surrounding area plus find hidden tombs or underground rooms/areas, never before seen.
yeah, I realied a possible use after watching this. on a galactic level, consider gamma ray bursts or other frequency light distributions that occur from bursts or explosions of stars. if you were a neigh omnipotent existence with unlimited computational potential you could scientifically use this strategy to map sectors of the galaxy. Sure, the immediate few light years are destroyed to generate the power needed for the scan, as well as the star itself, or even potentially not. he'll, you could scan an area of space and use the refracted back light to tell you about what existed there if you are some 4th dimensional existence where time isn't felt as linear. it wouldn't matter by the time it reached bounced off the planet and reached back to you it was destroyed/the planets relative time everything on it was long dead, you could still access it by "pulling up" that snapshot of space to explore the data set further. Especially if you could interpret everything as data and reverse it back into what it was with perfect comprehension.
So TH-cam basically decided to recommend this to me in 2019
Hmm
Right..
Devyani Patil thats so cool bro
Exactly
Saw this ages ago. It's back
I got in 2020 march
This is well spent 11min, wish there were more about this topic.
Marcus Sundbom exactly..
True
It was short, But, not that short as a "light bullet" if you watched the video:
- femtophotography.info
Infinite division of time
its bullshit are u stupid or what???
Double Slit experiment please....
that would be awesome!
It is not possible. Experiment is based on photons, we can see it in high speed, but not magnify it to photon level
no. its just light from a laser
the light would probably change its behaviour when it's being watched. i agree though, give it a try and make it possible
+mono lith
We really need to get an answer to that. It's such a crazy thing--
That you can just look at particles and they change on a quantum level.
2012: we have trillion fps camera, soon in your phone
2019, Iphone: can't adjust the camera settings yet.. we chose you 4:3
But you can though...
@@powerbutton679 Not completely, at least
@@ian8527
Why does no one use open camera???
I mean many do but no one talks about it...
You can if you pay for one of those $20 apps
@@thejam7129
Well, not on iOS, on Android smartphones...
2019 viewer here. That last line, "It's about time", did not get enough credit
I was actually thinking the same exact thing when he said it.
2020 Viewer Here. I Absolutely Agree.
Science abhors a pun like nature abhors a Dyson...
2021 and still agree 0_0
Its 2018 and I just saw this. What has happened since then and why people aren't aware of this? Shouldn't it have been plastered all over the news as a major breakthrough? Or I was just living under a rock this whole time ...
Valentine yeah.... agree
Ik right
I saw it today 😂
Seems, it wasn't THAT spectacular as it was represented. I guess, because it's just usable for still images, and not for moving things. So, what's the point? Maybe usable for some particular science cases, but that's it.
Nii P. it's not just just used for still images, they literally showed you the camera recording at the a 10 billionth of a second.
They should implement femto photography into the large hadron collider! That would be interesting
+Avelino Davila Brilliant idea! Faith in humanity restored.
+Feynstein100 no it isnt. Femto cameras dont work like that.
Almostbauws
Yeah I guess. They'd have to do the same experiment millions of times.
***** yes and it would be almost impossible. And not millions, but billion times.
+Feynstein100 The LHC does 10 million collisions a second. This technology, despite its vast number of potential applications, isn't suited for imaging collisions in the LHC, that's what they have their detector for.
Me : see how much the technology has improved today.
Also me : wait.. it's 7 years old
Lol me too
It now 10trillion fps by caltech
Haha right
No its actually 30 years old...this Raskar guy is a phoney, he is simply using a camera (called streak camera) that scientists have known about and using for many years. There was even a nobel price in 1998 for femtosecond spectroscopy. This guy is showing light going through a coke bottle, which is useless, will only work for TED talks which are all useless anyways.
@@nevertheless123 well he is much successful and doing something with his life unlike you
That last line was almost like a punchline in a stand-up comedy - It's about time. Loved it!
Screw scientific applications. I can finally take a picture of my wife with her mouth shut. My life is now complete.
Hilarious!
Scah Saint
This is so adult humor lol
Items needed for light project:100,000,000,000,000 phonesall on camera
slow motion
you are welcome
Walrus Maybe he found someone with a sense of humor.
+Scah Saint HEYOOO :)
I used this video for presentation during my final year course in Lasers and optics some years ago and I got the highest mark!
2020, first time seeing slow mo of a light beam. Amazing as it is, until I realize the talk was given 8 years ago! Now, isn't that something!
No it isn't :) Because it's not a slow-motion video. It's a time-lapse built out of frames taken out of several events. Still amazing synch and timing, tho. But not a slow-mo video.
Since i first found this video back in 2013 i have rewatched it probably 10 times either on my own or sharing it with others. This is amazing that we are seeing an event that moves at a speed so mind boggling fast and its not just interpolated data on a paper, it is actually physically visible in a way that no one thought could feasibly be witnessed.
A fantastic presentation by Mr. Ramesh, the concept is just awesome. But what was with the Audience - could they have been any less enthused?
Isn't that obvious? They like Pepsi.
I think the audience did a pretty fine job. They applauded, laughed at the right moments and even stood up at the end. Tf did you want them to do, scream like it was a concert?
@@NipapornP Well played!
They were social and commerce students
They are gender studies major
Extremely interesting and well presented!! Thanks for that TT.
AMAZING!!!!
THIS GUY put his life to good use👍👍
Dude(speaking from future 2019),you talk of changing the future,but no one knows about this research.....
*,theme song from MIB starts to filter through
The future happened at Fento speed that’s why we didn’t hear about it ... I finally saw this in 2019.
They aren't really taking a video of a single event. They are repeating the event a trillion times and taking frames at different instances in time to get one full event. So if you think you can use this as a slow-mo camera to capture a water balloon bursting, you better have a LOT of water balloons...
I think you wrong on this one. This camera sees light around corners, by capturing the light when it returns.
+DJrezafication "resimulated many times" - last time i threw caution to the wind when i heard that. now i think twice yes, it must be run again and again.
+DJrezafication it's relative, this is how light works, it's doing all over and over again, our cameras do these things too, only at 60 or 30 fps.
Miseew No he means the light beam is fired multiple times and the camera is actually recording millions of simulations of a light beam being fired and compositing it into one sequence.
+jonnypanteloni Yes, there are no sensors, no electronic components, no CPUs available that are fast enough to capture a single beam of light as it travels a trajectory that short.
Wow I'm 4 years late
its never late to learn bro
I'm 5 years
Subhodeep Roy same
5 Years 4 months and we have flying spacecars now.
5Y5M dude
The coolest and best Ted talk ever seen and undoubtedly one of the best video in whole TH-cam !!!
Epic! Very intelligent man Ramesh Raskar ! Love you and your teams ability
.
A talk from 2012 and it's 2019 now. 7 years hence, no implementation of this tech. Something's wrong with either the tech itself or the people who pass patents.
Most probably investors want to put their money into facebook-like apps... and competition like X-ray is well established.
Idk I feel like technology is far more ahead than we know ? They just keep us a couple years behind
Well, it's data heavy, and needs large and expensive equipment. Not everything can be scaled yet.
It's the tech, really. It's just an amazingly accurate timer that takes one photo per photon packet, just one femto second after the other, forming a time-lapse. Not really a slow-motion camera :) Amazing synch, nothing to say about that... but wrong sensationalistic aproach.
This is groundbreaking and I can't believe I hadn't seen it until now! We really need to reevaluate our priorities as a species; I'd much rather have seen this on CNN than Justin Bieber's latest offense. That was the day I quit going to them for news.
Also, notice how you can't see the light until it refracts through the medium? In other words, if there hadn't been a water bottle in the way we would never have seen the pulse. This is obvious to most, but it is fascinating to actually see it in action!! Astounding...
Good spot. If you aren't already in the field of alternative physics, we need a few more like you that can use their eyes & brain in concert! (providing you have a strong stomach, you do have to pick the few gems out of a load of stinking bulls***)
lynx tamer i think we already knew that because light seems invisible and we only see the affects of it bouncing off of all the objects. Otherwise we would be seeing the light and colors streaming by our eyes and filling the room all of the time. But that was very observant of you. I need to rewatch this to see what else I missed.
fake news
First TED talk I ever watched. I still come back to it after 7 years
This gave me chills, very cool! Thank you.
Now thats what we call a perfect standing ovation
Why not take the Coca-Cola label off?
+1nzi
"Coca cola did not sponsor this research. * fake grins * i just picked a random bottle and made sure to placed it in such way so the logo can be easily read,just so you know im not selling out or doing commercials for anyone"
I dont know who does the Hindu guy think he is fooling but not me that's for sure, its clear that he is doing cola commercial.
+hategoogle plus Yeah he really was insulting everyone's intelligence with that. He knew this would be absolutely groundbreaking video footage, and his lab likely shopped around. I know it's a small quibble, but this honestly put a damper on the whole presentation for me. I detest blatant dishonesty.
+1nzi Sponsorship monies...
He must have monetized from Coke as well.
Maybe they wanted to see how the light reflected off an opaque label, as rest of the bottle is translucent. :P
One of those TED talks on science which I can completely watch till the end. Beautiful innovations.
The best presentation of finding through research ❤️
2 minutes footage = 10 yottabytes xD
Tales Demidio yea how tf can they store that
They don't capture very many images. They may only capture about 100 images in total (I'm just saying 100 as an example. I don't know how many). Our own brain can comprehend about 24 frames per second, so 100 frames can produce a smooth 4 second video for us. Hope this makes sense.
Tales Demidio 7h byh
Not exactly true, the human brain interprets visual motion with a frequency of around 7-24 Hz. However, when interpreting visual information, some studies have shown that certain individuals (trained fighter pilots) can interpret what is presented to them visually in 1/220th of a second. This corresponds to 220 fps. The brain doesn't process "frames" but more or less direct light, so it's a tricky question. This website does a good job explaining it:
www.100fps.com/how_many_frames_can_humans_see.htm
They dont need that much storage. The recordings themselves are less than a picosecond long.
hyper lens, femto and Li-Fi technologies will valuable ... precious...
Incredible. Seeing round corners. Utterly amazing.
I have met this man in personnel. Very humble, down to earth personally. Ramesh has got number of unbelievable achievement in very short time. I am proud that, he is from my hometown. Congratulations 💐
Technology is amazing! I can't wait a few years to have a femto-camera in my cellphone
yes, femto camera.The most useless camera in the world, because you cant use it for anything.
+Almostbauws He mentioned the uses. Watch the video before commenting.
Aerys Zoldyk for normal people they are useless
For normal people? You mean the people that scientists make touchscreen cellphones for? Or how about your computer? There's plenty of uses for it, but I can tell you're a bit slow so it's not worth it to bother to explain.
Cosmos You have to repeat the same thing again a million times perfectly to get this video.
so how long until someone points this camera at the dual slit experiment?
@m ・ ́ω・ where did you hear that it? So youre saying if we could somehow observe the electrons without electromagnetic radiation that we WOULD see a wave??
Stunning. Groundbreaking ...
Thanks for shedding light on the subject
Now put this in a smartphone so my laser pointer looks like a light saber!
Check out styropyro in his recent videos he has demonstrated this
So anyone tried double slit experiment with femto-photography yet?!!
What would be the point, the electrons some how know when we are measuring it anyway.
***** What?
that is a brilliant question
revisit the michealson morely experiment
Kamran Younis what do you mean?
Amazing! This is truly awesome!
I love the praise in the comments for this TED Talk. This whole concept, technology, and optical science is fascinating, but more importantly the pace, articulation, and overall just extremely well-communicated message was superb!
Mind blown. I'ma go make myself a sammich now.
This is truly amazing research. Also, Ramesh is a great speaker and truly captivating the way he talks about his research.
WOW. What i learn today. We are really indebted to such a million years ahead thinking scientist. congratulation sir and thanks TED.
Absolutely mind blowing
Amazing .. you rock Ramesh 🌈
This is so exciting! I can't wait to see where this will end up in ten years, or maybe even as soon as five years. Technology is moving so quickly, there's no telling what will be done with this breakthrough!
nothing as of now. 6 years have passed 😐
Nothing available now, 10 years have passed
I never dreamed I'd see this in my life time. Thank you all so much!
WOW! really the best video on TH-cam. I've always thougth about those very very very fast time scales. Amazing.
Wish my computer was that fast.
my neighbour tried to run Batttlefield on his intel graphic ...
@@madlife7274 You should've called 911, because you witnessed an attempt to murder!
this innovation, make me feel like live in a cave. this is terrific!!
a light speed camera
A friend showed me a NOVA video that covers this, point by point... 9 years later. I told him I had *this* video from a decade earlier... Bullet through Apple, coke bottle, tomato, looking around corners... Everyone awes at the demonstration, but I hope this is being developed and grown, and not just the same old experiments repeated for the next video crew to film. One thing that _has_ come true, is that mobile devices have gotten cameras that arent just more megapixels, but record in much lower levels of light and at much higher frame rates. Good to see that prediction come to fruition.
absolutely astonishing
887 dislikes from conventional camera producers? I want to believe that they also liked this.
Some might be from people who hated this to be advertised as a "faster than light camera to take slow-mo videos of light" instead of "Synchronization tool to take timelapse frames with 1 femtosecond of increment on the timer". Precise and amazing? Yes. No slow-mo video, tho.
two ladies didn't clap at the end
Probably they were not Indians.
Perhaps they are part of the team or related and heard it a thousand times.
I saw 3 ladies who weren't clapping. And possibly 1 male too. :)
They were the military intelligence operatives who realised what they were seeing and weren't clapping because they realised the implications of India having this technology before anyone else.
Leave them alone....
Simply amazing. This is an astonishing breakthrough..femto camera technology...now 2018. To what level has this technology evolved? Unbelievable and very very good presentation! Thank you.
Well spoken.
Amazing accent
HAH That man was geekin when he said "It's about time" I love it
Mankind salutes you for such brilliant invention. Thanks to you guys today I saw the next Dimension of photography.
This is probably the coolest piece of technology I've seen in my lifetime. We're watching photons in motion!
Second watch in 2019-Still I am in awe! :P
2nd watch in 2020
what's going on with the tomato? it looks like cg? I think I'm missing something here
edit: it's a plastic tomato lol
there are sub-surface scattering controls in CG that work on similar parameters, so it would look like CG, well spotted
7 years, *STILL* the coolest TED talk ever
Fascinating. Seeing light slowed down - What a hoot!
May be it's better to remove the Coca-Cola adv.
why ? funds is mater for the great research, focus on Genius technology please, thank u
4:12 I thought it was an apple
#metoo
Ramesh ji
Khup chhan explain kalat
Thanks a lot.
There's something we should all understand before watching this video. We're not really observing a moving photon, that would be phisically impossible.
Cameras produce images from the information given by the photons that the recorded object emits. We simply can't see a moving photon because the camera needs to obtain these information (given by the photons themselves) in order to build the image, and it'd be necessary to have "something" faster than the photon the camera is "recording" in order to "see" it, so, it's meaningless trying to "record" a photon with a camera .
In this universe, the speed of light is a physical limit, it's impossible to overcome it beacuse that's the speed a particle can reach if it gets INFINITE energy. It is possible to get closer to it, we can reach 90% of it with a really huge amount of energy, with a way more huge amount of energy we'd reach 99%, then 99,9%, 99,99%... 99,99999999%, but we would never ever reach 100% or more; it would be necessary an infinite amount of energy. What we're seeing here is a complex reconstruction of photon trajectory after shooting millions of them. Something quite remarkable and interesting, no doubt of it. But it's certainly not "a single moving photon".
So, it's meaningless to "prove this technology with the double slit experiment", although it can seem very interesting.
crlsprz11 yeah I agree.....it's just a complesx reconstruction of photons trajectories over millions of time....hey I want to know does it makes some compromise on creating image of event because physical information get changed every time a photon hit matter and it can't detact all of it.....is it so?🤔
crlsprz11 i didn’t bother to read your whole comment because just the first paragraph was enough to get the gist. You have no idea what the technology and instrumentations that are being used by his “camera”. It may not be camera like at all and he just uses that terminology so the average person can understand. There are probably no frames involved but only and a terminology used so that he could equate the math and the speed difference to the masses. Once you actually know what this is that is capturing the imagine then rewrite your comment. You have made a lot of assumptions about something he has said absolutely nothing about.
No, it is not impossible to photograph a bundle of photons because as that bundle travels, as they have done with the laser burst through water, the photons reaching the camera to create the image are showing the larger bundle of photons they came from itself. Nowhere is he claiming it is a single photon in the coke bottle slow mo.
Duh. He said it was millions of tries and stitched together. Why did you think we didn't know?
What a coincidence. My children are named, Atto, Femto, Pico, Nano, Micro and Milli.
Funny story: Milli is the only one who doesn't get teased about her name.
Milli Vannilly :P
BOKU NO PICO
@@eye-yamstewpeed8254 *no*
Probably because I waited half my life for images of photons in (slow) motion, I'm as impressed with Ramesh Raksar's film now as I was when I first saw it a few years ago. Give that man a Nobel prize!
That's fascinating
We need to perform the double slit with femtophotography! Maybe then we can understand the paradox of light being a particle, a wave, or something else!
Phewwwwwwwwwwww!!! JUST finished watching the video of the bullet going through a coke bottle...it was a long year but was worth it, you will never get the twist...trust me
Totally awesome ...
Это потрясающе! Спасибо.
it is impressive that those high tech images shows nothing contrary to the accepted theories of light.
ikr
Thank you, come again
I can’t understand how a person would even dislike this video after watching it? You just experienced and saw light before dying out dude, respect that.
FANTASTIC!
Oh how Gavin Free wishes he has this camera.
This is unbelievable. I had no idea we were capable of this.
Seeing around corners with bounced photons. We've been doing that for hundreds of years. We call it a mirror. What he is doing is cool, but redirecting photons is old, not new. His new way has exciting applications though.
Great, thanks
me watching in 2019, August 24...interesting. 👍
what microprocessor they use for this
I think they would have used some experimental 256-bit bus capable microprocessor with custom instruction sets to attain sky-high clock speeds rigged with raid SSDs or heck even RAMs for primary storae of the photos.
8086
Wilson!
Interesting and well explained
INCREDIBLE!