Can You Solve This Shadow Illusion?


  1. Travis Keena

    Travis Keena4 hari yang lalu

    The best type of teacher leads their students to the answer, 👍. Although you clearly had to go outside the U.S. to get people on the street clever enough. Sorry fellow citizens, I've seen Leno.

  2. Richard Gibs

    Richard Gibs17 hari yang lalu

    i was in a loft conversion last summer and there was a black out blinds but the window was open just enough that it projected the row of houses opposite upside down in quite a bit of detail i found the pin hole effect fascinating but everyone i told just thought i was sad lol :(

  3. myjamismeme

    myjamismeme25 hari yang lalu

    What hapoens if u move tge paper closer to tge wall? Doesnt the image get sharper?

  4. revansidda wali

    revansidda wali27 hari yang lalu

    Is the camera man a Japanese porn cameraman , they way things get blur says this.

  5. souvik sikdar

    souvik sikdarBulan Yang lalu


  6. Science Love

    Science Love2 bulan yang lalu

    What if we cut a bigger triangle plz reply

  7. Andrew Hodgins

    Andrew Hodgins2 bulan yang lalu

    I just learned that magenta, or purples are not an actual color, but the brain's interpretation of blue and red without green. I did not know this! It would make for a good video. You could also include the 3 primary colors for pigment, cyan, magenta, and yellow. Just like the cartridges in a printer. Very different from what I learned in elementary school.

  8. Usama Uzair

    Usama Uzair3 bulan yang lalu

    It blends off the edges because of the small hole. Something related to refraction. And wtf is that? Projection of sun?? Phew

  9. Mohanad Azzam

    Mohanad Azzam3 bulan yang lalu

    why when you get the paper closer to the wall you would see a triangle!

  10. Carlos Leger

    Carlos Leger3 bulan yang lalu

    Poor camera handling, despite of what another person commented on the wall being properly focused and the shadow giving the impression of being unfocused, the camera wasn't given enough time to focus on the wall and afterwards for viewers to appreciate the shadow. It feels like it was recorded on a smartphone, that's why we see instances with both the people and the background blurred (e.g. minute 1:02)

  11. Rabo Karabekian

    Rabo KarabekianBulan Yang lalu

    Yeh, he gets by on deception. Every single person who pretends to present science has been coerced by unknowable people to lie.

  12. Viktor Birkeland

    Viktor Birkeland3 bulan yang lalu

    This is actually impressive, I don't understand why you even bothered to film this, might as well use just the sound from the video, since the pictures themselves are all out of focus

  13. Someone Human

    Someone Human3 bulan yang lalu

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

  14. Vinod Akurati

    Vinod Akurati3 bulan yang lalu

    That's because of diffraction... Image of the sun! Really!! When you try holding the paper with that tiny triangle shaped hole closer to the wall, you can see exact triangle shadow casted on the wall. Now, try to gradually move the paper away from the wall, the outlines of the triangle of the shadow become blurry and at a distance you only see the bright centered gradient of light which is passing through the middle of that 'triangled' hole. That's because the rays of light are diffracted at the outlines of triangle shaped cut in the paper. Of course it is not the image of the sun. It is just light following the laws of light. If you are not convinced, try the same thing with an artificial light (not a pointed one, we need something like Tube light which we use in our houses, you will find out why). If the circular shadow is the image of the Sun, then you should get a tube shadow which should be the image of the Tube light, which is never going to happen, all you will see is a round bright centered gradient of light.

  15. Idontknow819918

    Idontknow8199184 bulan yang lalu

    I am not sure if this is true. How can that be image of sun? What if we use a square shaped light source? I think it shows up round every time because of the wave pattern created by Photons (like the wave pattern seen in the dual slit experiment) which makes it look round. Kinda like when you look at a square tail light of a car at night and it appears to be round as the car goes away.

  16. Rabo Karabekian

    Rabo KarabekianBulan Yang lalu

    For god's sake, don't try these demonstrations yourself! And don't do any measurements - that's how satan get you.

  17. chrisPbacon

    chrisPbacon4 bulan yang lalu

    learn to focus the camera then we can believe you

  18. Rabo Karabekian

    Rabo KarabekianBulan Yang lalu

    yeh this is a stoopid guy who don't know no camera stuff. Reality is always simple and clear and don't need no edyoukashun or untelligents.

  19. bazoo513

    bazoo5134 bulan yang lalu

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

  20. Borbons Gaming

    Borbons Gaming4 bulan yang lalu

    Camera was focused. The shadows are just blurry because of how far these people are from the wall. You can tell it is focused by some of the details on the wall. And btw this explains why you see half circles on an eclipse time :)

  21. Yash

    Yash4 bulan yang lalu

    You didn’t see a circle. YOU DIDN’T....

  22. Kaleb Barbour

    Kaleb Barbour4 bulan yang lalu

    Well the sun is kinda round isn't it

  23. Prayash Pandey

    Prayash Pandey4 bulan yang lalu

    8 years ago: Wow the sun is playing tricks on my mind Now : tHe sUn Is pAiD aCtOr

  24. SilentBob420BMFJ

    SilentBob420BMFJ4 bulan yang lalu

    Try doing it with much bigger holes and you will see this so-called "phenomenon" disappear. So dumb... It's called blurred... Shadows are not precise.

  25. Rune Drejer

    Rune Drejer4 bulan yang lalu

    Well.... Just like a UFO video, out of focus 😂😂😂

  26. jonathan lopez

    jonathan lopez4 bulan yang lalu

    The camera man was spot on on the focus

  27. mphumani zuma

    mphumani zuma5 bulan yang lalu

    I tried it and it doesn’t work.

  28. That Goose

    That Goose5 bulan yang lalu

    It's a projection of the sun not the cutout of the paper

  29. Tarlan Mustafayev

    Tarlan Mustafayev5 bulan yang lalu

    If cardboard was closer to the wall they could see the actual shapes. It's just that the shadow gets blurry and because the shapes is so tiny, they lose their edges and become circles due to blurriness I think

  30. AdditionAddict

    AdditionAddict5 bulan yang lalu

    More of these please, like the 2 4 6 guess the pattern

  31. Tom Stein

    Tom Stein5 bulan yang lalu

    So if u get light from a light bulb will u see a bulb shape

  32. E G

    E G5 bulan yang lalu

    Use a square light, bet it still comes out round

  33. mchipitt

    mchipitt5 bulan yang lalu

    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.

  34. Travis Richey

    Travis Richey5 bulan yang lalu

    I love how you used the Socratic method on this to show people they already knew the answer. :-) ~Trav

  35. MrTough101

    MrTough1015 bulan yang lalu

    Why a 8 year video being recommended in 2019

  36. Ivo Kuzov

    Ivo Kuzov5 bulan yang lalu

    We actualy see the projection of sun. It is some kind of "camera obscura" ;)

  37. Anatoly Wein

    Anatoly Wein5 bulan yang lalu

    I stopped at 2:14, till now guessed everything correctly. I have an explanation till now. EDIT Watched, okay I was wrong, I thought that it’s actually a triangle but so blurred on that distance that it looks like a triangle.

  38. Jordán József

    Jordán József5 bulan yang lalu

    Can't see anything, because of the focus was not there at all.

  39. Emanuel Bandrabur

    Emanuel Bandrabur5 bulan yang lalu

    8 years later and I still don't get it

  40. Roy Anque

    Roy Anque5 bulan yang lalu

    We saw this effect by accident with a solar eclipse. It was crescent shaped.

  41. Kenn Cal

    Kenn Cal5 bulan yang lalu

    Try this on a solar eclipse. Thank me later

  42. Golden Eyes

    Golden Eyes5 bulan yang lalu

    That cameraman got fired

  43. Al Bert

    Al Bert5 bulan yang lalu

    This pin-hole camera effect would be very much enhanced if you are in a building with holes in the roof; the image is larger due to the longer distance, and the image is brighter due to the darkened room background. You can see clouds covering the sun, and would be great for eclipses.