Can You Solve This Shadow Illusion?

[@patuszodi7532]

3:00 was inspirational. Derek is such an amazing teacher/mentor. I just love how he brought out the answer from that lady.

[@patuszodi7532]

***** Wait, did you just taught by me?

[@patuszodi7532]

***** My job here is done, it looks like

[@harendrasingh_22]

+PattyMMelt haha

[@eliasjosephsson3994]

i agree that was awesome!

[@polyparticle]

Maybe. Cleverly edited this woman's voice at the end though kzbin.info/www/bejne/oprUd2l7ltKce5Y

[@RobertFrisbeeTAM]

I love how Derek doesn't tear people down, but builds them up.

[@amitshetty6359]

Signs of a good teacher

[@sammathew1127]

Yes.. that's such a great quality 👌🏻👏🏻💫❤

[@inferious777]

I think he has a degree in educational science or something

[@Damieru]

@@inferious777 yes, you are right. He's got a PhD in science education. :)

[@mk_rexx]

He doesn't run around and desert you

[@VK-pk8uz]

Right at the end there, when the girl said she didn't know but you guided her to realise she actually did know, that was amazing. Socratic questioning done perfectly.

[@hassaniq0777]

Hmmmmm 358 likes with no replies? Let's fix that

[@witherschat]

Exact opposite of Socrate's method LOL

[@dismalthoughts]

It's close, but I don't think it's quite the Socratic Method. Socrates would ask super basic questions carefully crafted to help guide a person to making the logical jumps that help them arrive at a specific conclusion on their own. Derek simply encouraged her, saying that she *does* know and isn't engaging the part of her brain that knows the answer. That was all :P Still awesome, though! I really appreciate how he encouraged her to get it on her own :)

[@witherschat]

@@dismalthoughts Only difference is that Socrate will bring you to a contradictory result, so you realize yo don't know.

[@dismalthoughts]

​@@witherschat Haha, yeah, the moment of "metanoia". Socrates' goal was still to ultimately guide the student to some higher truth, but often that first requires tearing down contradictory, indefensible beliefs, which he accomplished with deceptively strategic, seemingly mundane questions. The goal is Truth, but it requires first getting the person to realize their current ideas are indefensible and admitting they don't know (or at least that they haven't yet consciously realized). Actually, now that I think about it, I think this *was* the Socratic Method (just a gentler version than is typical lol). Socrates' first step (1) is to ask leading questions that lead you to "metanoia"--to realizing you don't know. Derek absolutely did this by asking people what they saw and what they thought was going on, occasionally helping them realize on their own (through strategic questions) when some of their ideas were erroneous. Socrates' second step (2) is to help you reach objective Truth (again on your own). This is where you could argue Derek *didn't* complete the Socratic Method since Socrates would accomplish this with more questions (this time not to erode belief but to help the student make connections) while Derek simply cheered her on lol. But he clearly completed step (1), and I think cheering her on still at least halfway counts as (2) helping her reach objective Truth on her own :P So yeah, my mind's changed lol. This was, in my view, a fantastically elegant and (possibly more importantly) refreshingly softhearted implementation of the Socratic Method :) Socrates got himself killed with how abrasively he employed his method. Derek used it to cultivate--not just knowledge, but--inspiration and goodwill :D Socrates would be beyond proud :')

[@vwr32jeep]

“What are we going to see?” Camera man: “Nothing.”

[@Sunny-Gupta1]

😂😂😂

[@narm455]

ههههههه

[@echoo200]

Man I am just bursting in the middle of the night

[@brightnight8831]

haha well done

[@TalhaShaikhani]

xD

[@fedor3000]

not one time was the camera focussed :/

[@liaamalia7324]

my thoughts exactly.

[@dramawind]

I think it was focused on the wall, but because the shadows naturally have fuzzy borders and the hands are also blurry because they're out of focus, it gives the impression of the camera not being focused at anything.

[@KyberEagleProductions]

Noob cameraman

[@ThuNguyen-jy2jt]

Yeah

[@Kev376]

I figured the camera guy was just stoned pressing all the buttons he could.

[@AverageAlien]

I'm so glad this guy is really inclusive and allows people with visual impairments to hold the camera

[@Fragrantbeard]

That was funny. I just barked a weird abrupt laugh.

[@Johan.Dingler]

Me too

[@rahulkhandelwal9323]

Come on man!!! Don't be so mean 😂😂😂😂

[@ShivamSingh-yl7jo]

I had to read this twice to get the pun

[@07Akash10]

This is Funny Comment 😉

[@commenturthegreat2915]

How can you know for certain It's a circle if THE CAMERA IS NEVER FOCUSED

[@百合仙子]

If you know the physics behind this, then you can be certain :-)

[@anandsuralkar2947]

Right

[@anferrr]

@@百合仙子 And you can also see the camera not being in focus as an hint in some wait too ! :3

[@deva8496]

Definitely he is not doing majic with his team to tell lie. So trust them

[@NickRoman]

Well, go cut a hole in some paper tomorrow and try it out.

[@morning5tarr]

*Cameraman was Stoned by vitamin-D.*

[@Soul-zj3wi]

Video was made a long time ago.

[@morning5tarr]

@@Soul-zj3wi yet KZbin recommending it now😆🔫

[@Soul-zj3wi]

@@morning5tarr yes, KZbin is smart 😂

[@morning5tarr]

@@iKraigory LOL😆🔫

[@o0blubblub0o]

i guess it's not as out of focus as it appears... the shaddows ae simply blurry

[@brunovaz]

If I ever want to show someone how it feels to have myopia I show them this video

[@kshitiz8093]

Exactly

[@transcent7]

I was squinting whole video...

[@cbhv4321]

what's myopia

[@Tiltproof]

@@cbhv4321 nearsightedness

[@Sunny-Gupta1]

I have myopia I can feel your pain

[@Thepc425]

Everyone “We see a circle!” Camera man “Not on my watch you won’t!”

[@DisiKleep]

So he recorded this with his watch? Oh, that explains blurines.

[@zoli604]

@@DisiKleep b r u h

[@uveermadho1471]

U tried pulling something there

[@kalisodia11]

lol

[@motifity3416]

OP I'm afraid you're about 8 months too late, there's another year old comment with the same joke with 3.4K likes. I am sorry for your loss.

[@pay2081]

3:18 Fantastic angle of the subject of the video...

[@sauliusltcool6902]

PAÐÐY ... lol What :DD

[@Thingumabob333]

LOL hilarious comment!!!

[@yuyurolfer]

2:42 "What we're looking at there is actually an image of the Sun" "Really??" * Looks at the sun to check if it's circular *

[@jazzabighits4473]

2:15 according to this explanation, the sun is triangular

[@avhuf]

@@jazzabighits4473 When the card is close to the wall, you will of course see a triangle, because the rays coming through the triangular hole have not converged yet.

[@Johan.Dingler]

JAJAJA

[@amitshetty6359]

@@avhuf right

[@amitshetty6359]

Or a bigger triangle will project a triangle on the wall

[@matszz]

An animation that explains how the sun rays travel to create this would have been helpful.

[@timearly5226]

matszz If you Google: pinhole camera inverted image and select Wikipedia, it has an explanation and a pic showing the ray tracing of light.

[@PrinceKashyap.]

Noted

[@mpadlite2925]

Not a reply..just a comment for those that also wonder:. To get a "better/alternative" explanation look up "camera Obscura" this is "in essense" just a very primitive camera/projector Best regards

[@astrocopter]

O>|

[@Redditard]

@@astrocopter don't poo here goto wc

[@williamchen5627]

2019: let's put this in recommendation

[@nawack1]

Same here

[@Xnichfrytk]

Lmao just realized. I thought it was uploaded today :v

[@ZaifSenpai]

lol same here

[@shaleenmundra8319]

same here :p

[@edumathv]

Same!

[@MrSlimJimProductions]

2:00 Man, what a straight-up, honest individual. I wish the world had more people like him.

[@roryreddog3258]

When I was a kid during a solar eclipse, light filtered through our tree onto our house and made thousands of crescent 🌙 shapes. This explains why...

[@jazzabighits4473]

i think you'll find its because of the shape of the leaves lol

[@samsibbens8164]

I had serious doubt that his explanation was correct, and you've just confirmed it to be true. Thank you

[@roryreddog3258]

@@samsibbens8164 :) 👍

[@roryreddog3258]

@@anonymous3658 makes total senses 👍

[@gordonfreemanthesemendemon1805]

this comment reminds me of that thing some games do where it says something like "press *triangle* 🔺 to enter", as if the user doesn't know what a triangle is

[@muntasirmahinsiam3657]

Camera: How much blurry do you want? Cameraman: *YES*

[@topsecret1837]

Did you forget this was in 2011? Chances are you weren’t even born yet. Actually kids born during the making of this video would be close to 10 years old.

[@TinglyShoopASMR]

@@topsecret1837 Chances? They are the chances? I don't like those odds

[@IronPal]

@@topsecret1837 ah of course because there were only 240p cameras in 2011

[@rum-ham]

@Avocado Toast What the hell are you guys even talking about? It has been completely possible to film non-blurry stuff for many many decades. It was 2011 not 1911....

[@199NickYT]

1:03 "It must be the sun..." Derek: :D! THAT'S RI-- "...playing tricks with my mind" Derek: *SO CLOSE*

[@pianissimo7121]

She was so close 😂

[@Prog47]

didnt see any of the shadows. out of focus

[@Gabrol]

Prog47 the shadows are actually blury in case you didn't notice

[@DavidBeczuk]

Gabrol these people have never heard of light Diffusion?

[@VulpeculaJoy]

Gabrol And because of the blur you can't see much but circles.

[@MelroyvandenBerg]

+Prog47 Haha, I think the footage taken was also out of focus. The camera men didn't know how to focus the camera as well. And the shadow is also blurry, making it very very blurry.

[@prosincr]

+David Beczuk the video itself is out of focus.

[@ohye4hye4h10]

Don't do drugs kids or you will have the skills of that camera man

[@ssimon64]

LOL!

[@TahirAli-ri3hn]

😂🤣

[@chriscornelius6669]

To be fair it's not like the cameraperson could use autofocus in this video, as there were two different depths of field that were constantly being interchanged as warranted. A great deal of time was spent focusing on the background image of the pinhole shadows while the people in the foreground were still taking up a large proportion of the visible frame... it's not possible to keep both fields in focus at the same time. The only workaround would have been to have everyone stand directly next to the wall. This wasn't practical because of the lack of physical space while simultaneously trying to hold the cutouts far enough from the wall to focus the pinhole's projected image. It's an either/or situation. Because the autofocus was out of the question, many times when switching back to the foreground image it was momentarily out of focus until manually readjusted. Compounding the problem was that many times the "man on the street" was holding the cutouts, & the pinhole shadow on the wall was, itself, also unfocused. So trying to focus on something that's already blurry while constantly swapping to and from the foreground manually was pretty untenable and I'm surprised it wasn't worse. The camera equipment typically used for Veritasium videos I'm sure doesn't have a real-time slider control to pull focus either... It's probably an up/down toggle situation. Summarily, I don't think drugs were the problem, but if you have any let me know. :P

[@moneebkhan3744]

@@chriscornelius6669 your sense of honour is the problem

[@chriscornelius6669]

@@moneebkhan3744 I was scheduled to fall on my sword tomorrow... 🤪

[@jacobsteinebronn2966]

This effect is really cool during a partial solar eclipse, you see crescent shapes instead of circles

[@kutsen39]

I remember that. During the Eclipse, we had a telescope sitting outside of our science center. It was pointed at the sun to act as a camera. You could watch the projection wane.

[@EdwardMcClung]

@@kutsen39 i remember walking a tree lined path i walk daily and the shadows from the leaves were all crecents. it was so crazy. We were already watching the eclipse so the day was already crazy but it made me think about how religions start.

[@sandal_thong8631]

That's what I was thinking! I wish I'd taken a picture of the leaf shadows a couple years ago.

[@r_a_]

❕

[@S3l3ct1ve]

Yes this is one of the ways how to spectate eclipse safely

[@bilal00276]

You needed a second camera man, this was so frustrating to watch

[@anandsuralkar2947]

True

[@shreksthongg]

@@curiousmolar8104 lol ikr. I'm sure if he did a similar video today it would be much better quality

[@Quantum-Bullet]

Ezra Levy hehe

[@deybsu]

yep it's really frustrating

[@aniksamiurrahman6365]

@@shreksthongg These days he makes video on how black holes look like, not how a tiny hole on a cardboard, LOL!

[@oldcowbb]

I love how they are so positive about learning new thing, If i do this in my country, the people will get mad and say this is stupid so they can look smart

[@ZeroMass]

Yeah now try this with a laser....

[@TehmasKhan]

I thought the same. 😂

[@bluemountain8110]

oldcowbb what is your country?

[@rockstarali99]

Lemme guess you’re either Chinese or Indian

[@thatdude6045]

I was guessing dubai

[@lizard455]

I've seen this in action during a solar eclipse! As I was heading back after the peak of the eclipse, I happened to notice that all the speckles of light in the shadow of a tree were identical little crescents instead of circles. I was already familiar with the pinhole camera effect since I had made one of those Pringles can ones, but it was still cool to see!

[@SarahC2]

That's the one this reminded me of!

[@SoulBruteflow]

"Well there you go, I've learned something today Derek" :)

[@bluelambo5]

I learn something new every day :)

[@reezy619yt]

I learned this once by accident when a solar eclipse happened in my town. The shadows in the trees created a thousand little crescent shapes in the holes of light through the branches.

[@sharonsolana]

@@YOLO-sp5bi Here you go: kzbin.info/www/bejne/j3-4hHSKpa2Cp5Y

[@notyayanguyen1735]

same

[@SilverMustang920]

Very nice. To illustrate this further, you should set up an experiment where the light source is of square shape, and then get a square image through triangular or circular cut outs.

[@spiderjuice9874]

You could highlight this by using a rectangular spotlight and demonstrating a rectangular image - otherwise one could postulate that an out-of-focus triangular hole would appear circular as observed. Kind of like a positive control.

[@dylanv3813]

Yeah my mind keeps going to the out of focus triangle thing, and I’m having a hard time understanding why the triangle makes a circle if it isn’t because the blur of the light makes it look circular

[@jazzabighits4473]

@@dylanv3813 It would be the blur of light making it circular (lack of focus). But like at 2:15, when he puts the paper near the wall, you see it makes a triangle. The sun isn't triangular lol

[@cheatcode9296]

Wow was the camera man also watching which shadow appears and forgot that he is holding a camera and he need to focus on the shadows. Maybe shoot in automatic setting that might give better result

[@fendelt838]

Cheat Code shadows are always blurry tho, and he’s focused on the wall.

[@ocea3237]

Dude this video was literally 8 yeas ago

[@cheatcode9296]

@@ocea3237 Just noticed it . Was on my recommended . But no matter how old it is bro dont you feel that the whole purpose of the video is defeated due to that camera man ? F

[@yvrelna]

The autofocus will just get confused. Autofocus is designed to focus on foreground object that are expected to be fairly sharp, not on blurry shadows. You'll have much better result to go manual and preset your focus level. Just keep yourself at a set distance from the target rather than trying to play too much with the focus.

[@cheatcode9296]

@@yvrelna *sarcasm*

[@bctalicorn809]

I found this out when we had that eclipse back in 2017, all the shadows from the leaves on the trees were little crescents, because that was the shape of the sun at that time. Super cool!

[@dulla8469]

does the guy shooting not know what focus is?

[@internet_typer]

This was filmed in 2011 mate

[@robertserban2008]

Tell me how to get a sharp image of a blury, fuzzy shadow?

[@dulla8469]

@@robertserban2008 thats not what im talking about look at 0:50 he zooms in at doesnt focus im not talking about focus on the shadow brudda im talking about focus in general

[@dulla8469]

@@internet_typer and btw im pretty sure focus was present in 2011 DSLRs cuse i have one that was built in 2010 and it has focus Manual and Auto

[@robertserban2008]

@@dulla8469 I am also pretty sure even laser focus is present nowdays, and still some very well known youtubers, who are using them, have some problems focusing.

[@swimen2768]

New vid title: A look through the eyes of a drunk bystander

[@yuki97kira]

Really just strapped a go pro on a random drunk dude and used the footage

[@MrARock001]

I remember being unexpectedly confronted with the pinhole camera effect when I went into an unlit storage closet that fronted onto a bright afternoon sun. There was a small opening somewhere in the doorframe and when the door closed, the back wall of the closet turned into a perfectly in-focus (just coincidence I assume) upside-down projection of the street outside, complete with people walking around and cars passing and everything. It was one of those rare real-life mind-explode moments.

[@lodewykk]

=_= Come on now the thumbnail is clickbait. You won’t cast that shadow with that large of a triangle. EDIT: Lol I see the video was posted in 2011. It’s a product of its time then, I guess.

[@Corn0nTheCobb]

Yeah, but if they showed the actual size in the thumbnail then we wouldn't have any idea what we were looking at

[@lodewykk]

A close-up zoomed shot of a small card with a small hole and it’s shadow could have shown both the hole and its shadow in focus, giving proper context. In the thumbnail the blurred area around the circle isn’t even large enough to produce the shown effect.

[@greenrobot5]

I always dislike and unsub from channels that do clickbait

[@Genny207]

This is probably why this video is getting recommended 8 years later. He changed the thumbnail recently (as per one of his recent videos highlighting the youtube algorithm), and it's getting people to click on it.

[@woodfur00]

Jason Klugh Alright then, disliking the video in hopes they learn better. I used to trust Veritasium but it sure does seem like pandering to the algorithm is taking precedence over quality educational content lately.

[@LyricWulf]

Lesson: The sun is deceptive.

[@chloejc7039]

Tricksy sun!

[@billcipher2144]

[@rohitbairwa2390]

KZbin recommended it after 9 years. Let's see..How many peoples are watching this in 2021!? 👍

[@nadeempandith1182]

🙋‍♂️🙋‍♂️🙋‍♂️

[@dinosaur8150]

Cucuma

[@KrishnaKumar0205]

Myself bro👍

[@mjbhuiyan1]

🙋‍♂️🙋‍♂️🙋‍♂️

[@kurokaminari4566]

Meee

[@jmcbresilfr]

KZbin: *makes a new algorithm* Veritasium: Ok so I'm gonna do what's called a pro gamer move.

[@Slayer1111111111able]

I'm going to back in time eight years and make the perfect video. They'll never expect it

[@dazonic]

@@Slayer1111111111able Nah, it was easier to just bait up all my thumbnail on my old vids

[@animeislife3000]

Hehe I get the reference 😂

[@ryuksenpai6137]

@@Slayer1111111111able I see this one year later 👀

[@damiangames1204]

Comments here: 50% cool 50% why no focus

[@drabberfrog]

99% about the video 1% about comments about the video

[@jitendradara2502]

99.85% about video, comments and comments about the video 0.15$ about comments about comments about the video

[@RayMak]

I hope I can see the shadows clearly here

[@maruftim]

no

[@delq]

Bro

[@Konvicct]

How are you here too 🙄 ... Did you find a way to know which videos are recently showing in others recommendation 🤔

[@potatoslayer5963]

Pls change your pfp, you could do better

[@Uuuh...hein...]

damn....I didn't expect you to be here too!!!

[@williamhayden7711]

Anyone that has ever observed an eclipse would've used this method to save their retinas from burning out. :)

[@Soulmaster187]

I think people are just using special sunglasses...

[@kjpmi]

Soulmaster187, he's referring to the technique where you place a pinhole in a piece of cardboard. You can then hold it up to the sun and observe without it destroying your eyes. The pinhole lets the scene you're observing come through, but it's much more dim. Like the first hole and second hole in this video projected at the same size but the smaller hole was much dimmer.

[@jlco]

I don't think that will protect your eyes, but it is neat to observe that the light from the pinhole will look like a crescent/chipped circle during a partial eclipse.

[@fuzzidelic]

Unless you're the POTUS and then your eyes are invincible.

[@coryman125]

You can view an eclipse without a pinhole camera (but only if it's a total eclipse- and maybe double check before trying it and don't just trust me :P ) Also I don't think the pinholes for observing the eclipse are just held in front of your eyes. Usually they're made to project the image onto a piece of paper or cardboard or something, and that's what you view, otherwise you're still staring directly at (a small portion of) the sun

[@samimentes3039]

i think you are both wrong! well the reason can be explained again with a hypothetical pinhole camera. if we consider an infinitesimal hole where only one photon can pass, every image will pass to the sensors perfectly but reversed. since piercing such a pinhole is practically impossible, even a very small point pierced will let more than one photon passing through. in this case one single point on the image will correspond more than one place on sensors which results the phenomena we call blur. this is why we use lenses instead of holes in modern cameras. same principle applies here, in a certain distance, which is out of focus of sun rays, will land so inaccurately it will produce a blur, which means a less detailed triangle: the circle. this is also why if you shorten the distance of pierced paper enough you will have a more accurate triangle not a circle. or basically cut a bigger triangle.

[@timohuber536]

Lyapunov Exponent you made my day sir, thank you very much!

[@nauka7565]

Thats what I was thinking until he blurted out the answer

[@me.unpredictable280]

Oh if it was a blur, it'd have still been a triangle, just blurred. Edit- you can approximate the ratio between size of sun versus distance from earth by measuring the length of shadow gradient (not a term) from an object at a certain distance from a wall.

[@vrajpatel2881]

@@me.unpredictable280 well they didn't see triangle on the because the hole of triangle on the paper is so small that the light rays diffract sense resolution is lost. That's what he called blur

[@me.unpredictable280]

@@vrajpatel2881 mathematically, if the shape of triangle in hole is visible, no matter what you do, until luminosity is enough so the see the light in screen and source isn't converging there is no way you won't see a blurred triangle if diffraction is what is happening. Also, I am talking about a hole visible to naked human eyes.

[@someonehuman3369]

I love how geeked out and excited Derek was to test these guys

[@dettonator6]

I'm actually glad this was in my recommendations. You're a great teacher, Derek!

[@adfggffffffddffd]

I love how Derrick doesn't just tell them the answer and makes them come to the correct conclusion on their own.

[@RyanHainesRyeBread]

Glad to see where his videos have gotten 9 years later. Glad you can focus better!

[@a7mad9999999]

who needs school when you have vertasium

[@DoomRater]

Speak for yourself, despite being raised at a Lutheran school till 8th grade I know I've seen this model at least once growing up in addition to inside a Highlights for Children magazine. Then again I remember Square One as well growing up.

[@thembones5]

And Vsauce!

[@anmol3]

Well, Veratasium doesn't exist thou 😂😂

[@n0nenone]

@jabberwolf Lol just a piece of show off 😂

[@Beyond-Studios]

Three words: waves and optics. It is not an image of the sun as you say. Because the sun is extremely far from the focal point of the pin hole, its rays are essentially parallel when approaching the pin hole. When imaging an object with a pinhole the light rays need to come in at different angles to form a corresponding projected image. Here's what is actually happening: Photons, like other subatomic particles, behave like waves and therefore distribute on surfaces with guassian probabilities like this. The circular projection is the result of the gaussian distribution of photons being round regardless of the pin hole shape.

[@MarkLawry]

You are thinking too hard. Go back and look how a pinhole camera of an eclipse works. The rays are not parallel.

[@TimothyKNetherlands]

This reminds me of making a small hole with your finger. If you look through it, things appear sharper. E.g. if you wear glasses and take them off, and look at some writing, you can now read it without glasses. This works as long as the aperture is small enough compared to what you want to measure. It basically functions like a lense. What do lenses do? They project, and that's what we see here. Took me a while to relate that to this video, thank you, great vid as always

[@nitinprakash388]

Your camera person seems more excited though.😢 You could've showed him this earlier all alone.

[@squigglylines420]

That lady xD "the suns round" * derek agrees * " the buildings round" * derek facepalms *

[@jocax188723]

Honestly, I found out about this phenomenon when I experienced a total eclipse and noticed every shadow suddenly making crescents.

[@solace293]

*KZbin's Algorithm Summary* 2011: Nope 2012: Nada 2013: Not doin it 2014: It's not *ripe* 2015: not quite 2016: almost 2017: a little more time... 2018: almost fully ripe 2019: *perfection.*

[@spreadyspready5128]

d

[@lyrimetacurl0]

That's a lot of years, wow, where has the time gone?

[@lukemateo6924]

U can stfu up now that coment is so burntt

[@ShadowVipers]

Stale comment

[@solace293]

ShadowVipers it's only fitting for a stale video 🤷🏼‍♂️

[@GotPoffins]

I learn more from your channel than I do at school. Well done, man!

[@thehornet7928]

That's sad. Also, I love your Avatar picture!

[@RomelMaldonado]

I love rewatching these so many years later. Thanks Veritasium!

[@sikhswim]

Can we do a remake of this video. At what hole size does it cease to be a pinhole camera and just reflect a straight triangle? :)

[@vinyak123rohatgi]

If you bring it closer to the surface it will show the shape. Like focusing the camera

[@seraphina985]

@@vinyak123rohatgi Actually that is losing the focus which is why the projection is no longer discernable any more, there is an ideal diameter for the hole for a target focal length d=2*sqrt(f*λ) where f is the focal length and λ is the wavelength. Use a wavelength of 550nm (Yellow-Green) for visible light as this is nicely centred in the middle of the visible spectrum.

[@mansoorshaik1991]

Only a point type source can make it to be a perfectly triangular image. Everything else will be a triangular image with circular edges radius of which keeps increasing with distance from the cardboard to wall

[@mansoorshaik1991]

@@vinyak123rohatgi Only a point type source can make it to be a perfectly triangular image. Everything else will be a triangular image with circular edges radius of which keeps increasing with distance from the cardboard to wall

[@mansoorshaik1991]

@@seraphina985 Only a point type source can make it to be a perfectly triangular image. Everything else will be a triangular image with circular edges radius of which keeps increasing with distance from the cardboard to wall

[@jesse-dg8yx]

I once saw a video about this. The teeny tiny holes of sunlight that manage to sneak through a trees leaves, during a solar eclipse those tiny splashes of light turn into a crescent moon shape

[@RyanWilliams222]

Or a crescent *sun* shape!

[@DustInTheWindAZ]

This was demonstrated to me back in the early 90s during a partial solar eclipse. I had made a similar "pinhole camera" to view the eclipse, but when I stepped outside, I saw numerous images of the eclipse in the shade of a tree! Everywhere the light came through the leaves and hit the ground, there was an image of the eclipsed sun! It didn't matter what the shape of the "hole" was (they were quite irregular in between the leaves). That was totally amazing!

[@rushikeshkarandikar4343]

I was thinking about diffraction and all sorts of science stuff I learnt, to know its the sun we're seeing. Wow! XD

[@glkglkglkglk9193]

Yo , i was searching the comments to see if anyone thought of diffraction like I did ..

[@rushikeshkarandikar4343]

@@glkglkglkglk9193 Yeah XD

[@theymi]

@@rushikeshkarandikar4343 Why isn't this diffraction? 🙈

[@xinquiote9572]

Wow, it's blurred. The video is playing tricks in my mind.

[@MichaelWillems]

For me as a photographer this is obvious, but it’s great to see people analyze this. Especially the woman who did photography. Great stuff.

[@Coldtrojan]

Hey, I love learning in general but your videos specifically just make me smile when I watch them, awesome job dude! :)

[@PrimeGaming10]

That blur image of shadow at even at 1080p is making my eyes sick

[@mchipitt]

Gosh I love how you make people think and get excited about it kinda like I tutor my friends, they all think I'm whack but I just really love to show people they're capable of critical thinking.

[@ramanujraman_]

When we were in 6th standard we were told that light travels in straight line and now in 12th standard we were told that it bends from it’s path. Well no doubt light has learnt to bend as it grows up.

[@abhishekwaghmode8190]

I think this is what NCERT CLASS 12 Part 2 says! I guess?

[@abhishekwaghmode8190]

By the way, where are you from? Your acsent doesn't seem Indian

[@ramanujraman_]

@@abhishekwaghmode8190 yes it is. And I am an Indian.

[@TeslaLiam]

Do you know what *FOCUS* is??

[@shreksthongg]

Video's only 8 years old. Hopefully he'll learn once he gets more experienced making videos

[@jaydevsingh3067]

oh common. that shadow was blurry. that's why the camera is struggling to focus

[@dozog]

The sun made an image without focusing... Why can't the camera?

[@BN99239]

I really applaud Derek not putting people down. His goal is for people to want to continue learning. That's why teachers that put students down are the worst. Sure, now the student knows that they're wrong, but they are no longer encouraged to learn, or at least they are discouraged from making mistakes, and therefore won't learn as effectively due to fear of failure.

[@mponcardas94]

Your videos encouraged me to pursue physics. :D

[@fiG34jk]

Could you please do that again with differrent type of lamps. For example a square lamp, a honeycomb shape lamp and so on? Would be really interresting to see that

[@Alexman208GR]

You have to check out what shadows looks like during an eclipse, just google: "shadows during eclipse"

[@effyleven]

I spotted that one straight away. It's not because I am clever, it's because I too trained as a photographer, and I remembered the pinhole camera produces an image of the light source.. However, out-of-focus highlights in lenses with shaped diaphragms, DO reproduce those highlights as being the same shape as that diaphragm, very often a pentagon or hexagon...

[@abdulmanaf7130]

When solar eclipse happened in Indonesia few months ago, I saw shadows turn into crescent shape.

[@753238]

What I saw is cdn. ebaumsworld. com / mediaFiles / picture / 2183782 / 85046402. png

[@jasondeng7677]

this camera is less focused than me in chinese school

[@executorarktanis2323]

You grown a whole year since this comment

[@jasondeng7677]

@@executorarktanis2323 comment still holds true

[@executorarktanis2323]

@@jasondeng7677 fact

[@executorarktanis2323]

@@jasondeng7677 a strong will and determination still stayed with you or even grown stronger

[@bigpopakap]

This is the epitome of these old Veritasium videos: he does such a good job guiding people to the answer with minimal help

[@yokemartianda]

Uploaded 2011. 2019 KZbin algorithm: Let push in the recommendation Me: don't mind, still good video tho

[@Veins1]

yeah wtf youtube?

[@chubs2312]

Same

[@ConfusedRambutan]

2021 algorithm too

[@rishianand153]

Bring the card near the wall and u will find a triangle. Now where did the image of sun go?. I tried this...

[@sploofmcsterra4786]

2:16 this lady is really good. She's not looking to prove her intuition, she's actually observing what they're seeing and pointing out that it contradicts with their intuition. She did the same thing when pointing out that the size of the circle was the same for both circle holes.

[@Xqvvzts]

This would be so much better if you actually filmed the shadows properly.

[@nowonmetube]

Girl: "The sun is deceptive" Quantum physics: "No"

[@transcendent5158]

Oh Derek you magnificent creator, you, keep broadening people's minds, you have no idea what a beautiful gift you give

[@babablass2347]

2011: I want the best recommendation 2015: I said the best 2019: perfection

[@rutramp4195]

So if the sun was a shape of a triangle, you would see a triangle on the wall?

[@hyperthreaded]

rutramp yes. Actually during a partial solar eclipse, the sun has the shape of a sickle or an Apple with a bite taken out of it, and you would see that in this experiment.

[@rubenv.3106]

rutramp yes, just look at this solar eclipse /watch?v=EQQByou74TY

[@adharshk2838]

Thank you Derek for showing how important a cameraman can be...

[@RedsBoneStuff]

Now imagine the Sun being triangular :)

[@RedsBoneStuff]

How about a tetrahedron? That is not flat and seems triangular from most perspectives. Anyway, my point was that a triangular light source would leave a triangular projection through a small hole, regardless of the hole shape.

[@RedsBoneStuff]

I know that XP I don't tell my imagination though. It sometimes comes up with cool things, so I wouldn't like to limit it via physics.

[@PrithviSinghhtk97]

it is not possible , every thing in this universe wants to be a sphere thats cuz thats the lowest energy possible !!!for any thing!!

[@Xnerdz1]

The sun should be a cube like in Minecraft!

[@RedsBoneStuff]

***** Lol, true!

[@delq]

This is exactly the circle my geometry teacher taught me.

[@noidea830]

Here's come another questions: 1. When the hole is close to the wall, the shape of the hole is clear. So, what's happening or how the shape is changing until it becomes the shape of the light source? Is there something like the focal length of the hole? 2. If the light source change in shape, or say a television, can the rectangle or the video be projected on the wall?

[@Observ45er]

The cause of this is because the sun is not a point source. The sun is a disc about one half degree in diameter. As you move the paper away from the screen you will notice that the edges get fuzzier and fuzzier. This is the PIN number or the area that is only illuminated by part of the sun. The bright center of the hole is limited by the entire surface of the Sun and the darkest part has no illumination from the Sun. When the hole is small relative to the distance to the screen it approximates a pinhole camera and you indeed to see an image of the sun.

[@mansoorshaik1991]

We have to consider following points to understand the phenomenon 1) If the light source(sun) is point type, then in this case, we should see a triangular image for a triangular hole in cardboard. And , the as distance between card board and the wall changes, the triangular images size nearly stays same since sun’s distance to cardboard is very very large compared to the distance between cardboard and wall. (Distance from Point type sun to cardboard)/(size of hole on cardboard)=(Dist. from sun to wall)/(Size of image on wall) To double the size of image , we need to make the distance between cardboard and wall same as distance between sun and cardboard 2) If the hole is point type,i.e., a pinhole, we should see the inverted image of the sun. And, as the distance between cardboard and wall varies, we get varying image diameters of sun accordingly to the following formulae (Dia of sun)/(Distance between Sun and cardboard)=(Dia of image)/(Dist. b/w cardboard and wall) Combining points 1 & 2,we get a situation where we have multiple pinhole images side by side across all the points on the triangular holes image

[@justinjohnson4278]

This was the coolest effect during the eclipse

[@mansoorshaik1991]

To watch solar eclipse, use a mirror to cast a reflection of sun on a wall faraway, then u can see the Cresent due to eclipse

[@carlotognazzo6081]

WRONG! This phenomena is called "area shadow" in 3d graphic. When an object casts a shadow, it's very sharp when it's closer to the object, and it becomes more and more blurred while it gets far from the object. Try to look at the shadow cast by a streetlamp onto the road: the shadow of the base is sharp but the one of the lamp is blurred. And this is because the light source is not a point without dimensions but it's, for example, the sun, that has a dimension, and this cause the light rays to be cast not all parallel. If you try to put the sheet with the hole very close to the wall, you would see a perfect triangle shaped shadow, and the more you bring the sheet away from the wall you would see shadow becomes more and more blurred, until you're not able to recognize the shape anymore.

[@roostewrum]

+Carlo Tognazzo Do it during a partial solar eclipse and see what happens.

[@ZevHoover]

+Carlo Tognazzo he is not wrong. this is not just an area shadow. it is blurred a little bit (like an area shadow), but it is also acting as a pinhole camera like he said in the video, and a pinhole camera will work with non round apertures.

[@aashiquesadique6081]

Cant believe it is 9yrs since I last saw this video. Still as interesting as before

[@Kuhchuk1]

I'm about 890% positive that I've got a pretty good idea of how this works, but I think the video would have been better if you'd explained what was going on.

[@199NickYT]

Think about it this way. The hole is so small that only, say "one ray" from each part of the sun can get through. Since they are all coming from slightly different directions, they pass through the hole and emerge inverted on the other side as an image. It's basically acting as a lens.

[@Kuhchuk1]

Also, meant to say 90%, not 890%

[@TheBlaze4000]

charlesburton95 There's an edit button...use it.

[@Evan_Case]

KZbin Comments Suck hehehe

[@bazoo513]

"There's a part of your brain that knows the answer" - great, Derek! This usually *is* the case.

[@rubiks6]

If you held up a card with a small circle cut out and then put up the card with the triangle cut out with about a half meter in behind the circle card, allowing the tiny circle of light to shine through the triangle, you'd see a sharp triangle on the wall. I'm 10 years late, but this was a fun experiment, Derek. Thx.

[@GerikDT]

It really loses its purposes when the footage is so blurry.

[@wetarbedfatass]

Me:*sees the thumbnail* Wait.that's illegal

[@turpialito]

I saw this back in the day. 9 years later KZbin recommends : / Oldies, but goodies!

[@ImPDK]

Does anyone know the physics behind this? I would really like to know more :)

[@Rwdphotos]

www.cambridgeincolour.com/tutorials/diffraction-photography.htm www.google.com/search?q=aperture+shapes&client=safari&hl=en-us&prmd=isvn&sxsrf=ALeKk00Ck18y9h3zGqhwitXCPL02NEtN5g:1596437254072&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiRmr2buP7qAhWqIDQIHWjnAcEQ_AUoAXoECA8QAQ&biw=414&bih=719

[@matrixin1999]

en.wikipedia.org/wiki/Pinhole_camera

[@johnjordan3552]

Physics:it just is

[@DANGJOS]

It's mostly just geometry.

[@ElifYlmaz-zb8kq]

It's because the triangle is so small, far away from the wall and unclear that it looks like a circle. You can see that it's a triangle by getting it closer to the wall or just cutting the shape bigger first.

[@ynntari2775]

this didn't actually explain anything, why is the hole making a projection of the sun?

[@samfisher645]

Refer to pin hole camera. It's actually an inverted image of the sun. At a certain distance, the infinitely further away object passes through the pin hole and gets inverted at the hole. Anything can be a 'hole' if it is far enough from the screen.

[@MILPICS]

It's blurred traingle made at infinity distance.

[@kittyissu]

if you put a small hole in a dark chamber you will see all the image outside projected inside the chamber. That`s how photography was discovered. But the whole image behind this hole was just the sun, so you see the sun

[@DANGJOS]

Imagine each point of the sun letting out rays of light in all directions. The pinhole only allows straight rays of light through, which forms an image of the pinhole on the other side. Let's go with the triangular pinhole. All of the points on the sun are arranged in a circular pattern. So you have all these triangles arranged in a circular pattern on the wall. Once this circle is larger enough, all the concatenated triangles build up a blurry circular image.

[@KatieLifts]

isn't this just difraction?

[@Lilithe]

I'm surprised you didn't bring up eclipses. It's pretty neat to see the corona on the ground between every leaf, etc.

[@kanishksharma1716]

A real and laterally inverted image of the sun. Paying attention in school really helps in some situations

[@eiebsrebla]

I mean it’s cool, but it’s never really explained WHY it’s a projection of the sun. Can anyone tell me or send me a link to an explanation?

[@seraphina985]

The wikipedia article on the camera obscura has some details on that. In short, it is because the Sun is so much larger than the hole. Worth checking that article though has a really great example photo of this effect with the holes in the leaf canopy of a tree projecting a partial solar eclipse.

[@daves.9479]

If the card w/ triangular hole is held against the wall, the illuminated portion will surely be triangular. If the card is moved away from the wall 1mm, the illuminated portion will probably still be triangular but perhaps somewhat fuzzed at the edges? How far way from the wall must the card be moved for the illuminated portion to no longer be seen as triangular? I just tried this: thin cardboard w/ a 1/4" eq'lateral triangular cutout. It can be moved at least several inches away from a surface and still retain the triangular projection. Prob. a function of the size of the cutout in relation to the distance away form the reflective surface; at some distance the cutout starts to behave like a pinhole, or the projection just gets so blurry that it appears circular.

[@boratsagdiev5707]

3:26 Weyy theyy yu _GOAUUU_ ouaiv _LUUND_ samthing tudoai _DEEREC!_

[@syamsoulazrien6044]

Thx bro

[@carazy123_]

Hahahaha