Can You Solve This Shadow Illusion?

we have that card with a little round hole in it and what I want you to do is hold it up and try to cast a shadow on that wall there and I want you before you do it to predict what we're going to see cut out the car shatter the car a little hole in it will see that figure enlarged on the wall it's not very pronounced but you can actually do see the little holiday and of course me so cool my next question for you is we have this card what's that like let's pick a hole can you tell me what size circle we're gonna see like compared to the other one yeah twice the size maybe but still the card with a larger round hole what do you see bigger hole the card and the hole slightly bigger than the previous one and the same thing just larger okay what I want you to do same size though it's approximately the same size as the lawn why don't we compare it here you go hey Ron it is ones just fine to the other well goodness it actually looks about the same same size hole okay I can't believe that it's must be the Sun playing tricks with my mind what about here's really gonna test you right tell me about what's on that card before you put it up trying yeah okay so what do you expect it will see on the wall a triangle but I wouldn't be surprised it wasn't so cool what are we gonna see your angle I'm dreading okay let's have a look oh wow that's all good for me cool it'll be a triangle well we're not gonna see a triangle I'm not guess everything else has been a circle so it'll be a circle I'm sticking to triangle okay have a look I'm interested well there you go it's so cool you want to compare it to the one of the others I'll give you the one do you want oh my goodness I really like this project I'm learning something the Sun is definitely playing tricks my mind the Sun is deceptive actually why are we seeing circles with all these cards regardless of the shape of the whole I really don't know I'd like to know when you take away the definition from any kind of shape it ends up being just round to our eyes there for example you get a perfect triangle but it was a pretty decent circle so MA see you must get to a certain size here doesn't matter that what shape it is it's just turned back probably why is it going to a circle though you look at the Sun it looks it around doesn't it I'm not sure if that's got anything to do with it well the light is going through these little holes and it is the Sun the sun rays just sort of um going through the pseudo holes making circle of the Sun I don't know you tell me exactly you know that what we're looking at there is actually an image of the Sun yeah Wow that's round in the Sun Tran yeah the Sun the sun's round I guess things around the buildings round is it my buddy's not round so what we're seeing is a projection of the Sun I've never thought about it before I think that you actually know and I think you have actually thought about it but you're not cueing that right part of your brain that knows the answer yeah probably there's a part of your brain that knows the answer well I did photography at school um and we did pinhole cameras the hole actually reflects what it's showing on the wall so so you see what you see on the other side what's that so it's a Sun well there you go that's something today Derek

Channel: Veritasium

Views: 2,164,278

Rating: 4.7581177 out of 5

Keywords: science literacy, experiments, pinhole, image, shadows, light, pinhole camera, shadow, experiment, physics, optics, science demo, demonstration, sun, sunlight, ray optics

Id: liqF6EamiE4

Length: 3min 31sec (211 seconds)

Published: Mon Jun 13 2011