Online Illusions

What's up, DONG fans? My name is Michael. And if you know me, you know that I love eyelashes. I have tabs open on my phone, on my laptop, on my desktop. Just hundreds of them, thousands of them saved in my history. I like collecting websites, which are things you can now do

online

. I went through my collection recently and pulled out all the ones that were optical

illusions

. These are

illusions

that I've discovered in the last few months or remembered in the last few months that I wanted to remember and I thought, hey, I'll just share them with you here in a DONG.

Let's start. Now, you can't talk about optical illusions on the Internet without talking about Michael Bach. His website is phenomenal. First of all, it's interactive, meaning you can really play with the parameters that make the illusion work. I want to start today with the ghostly look. Illusion, now take a look at this person's face. He clearly seems to be looking to the left, right? But now let's lower the blur and see what he's really looking at AHH!!! Us. Pretty creepy right? If you blur the image. He appears to be looking to the left, but removes the blur.

He's looking right at you. So what is going on here? Well, this is called hybrid imaging. It is built from two things. One has what's called a high spatial frequency, which means there are a lot of edges and details that are very fine. The other one has a kind of low spatial frequency. It's more spots, not many edges and details. The amount of information you get from both depends on how close you are to the image. If you are close to an image, its high spatial frequency, the lines, the contrast give you a lot of information.

But the big blurry vague shapes just don't mean anything, but if you zoom out you lose your ability to really discern what you're getting from the fine details and the vague ones start to paint a clearer picture. You've probably seen an even more famous version of this involving Albert Einstein, haven't you? I'll take out my phone, turn on the camera, record a video, and show you what happens to Albert's face as I walk away. I'm sure you've seen this one before, but don't worry. That was a photo. Here comes a video. Alright, there's Albert, but now let's go and the first thing we'll notice is Hannah waving.

Hey, she wait a second. Where is Albert going? He's turning into Marilyn Monroe. Well, actually the further I get, the more I'll look like Marilyn. Let's see what happens if I zoom. Ooohhhh it's Alberto again! uhh that's not his name, Alberto. But if I get closer, Einstein appears again. This works the same way the ghostly gaze illusion works. Here's a slightly different version, but it's split across the two images. We have a high spatial frequency image of Albert Einstein, which means lots of fine details, high contrast edges. And then we have a very soft image of Marilyn without much sharp detail.

Monroe Up close an image like this of Marilyn Monroe is difficult to decipher. It's hard to tell, but the details of Albert Einstein's face are easy to see. As we move away, the fine details are lost, we lose Albert and the vague, muffled shapes begin to mean something to us and Marilyn emerges. Pretty impressive. I have now linked articles below that explain this in more detail. Much of this work has been initiated by Aude Olivia. I highly recommend reading them. Obviously, what I love about Michael Bach's website is the fact that illusions exist. Interactive. You've probably seen this ambiguous dancer before.

The ambiguity lies in which direction she is turning. Is she turning clockwise or counterclockwise? Well, as soon as you look at it, your brain makes an assumption and it's often hard to switch and see it from the other perspective, but some friends come over and you'll be surprised that they think she's moving. a different way. This often leads to arguments about what the figure is actually doing. But Michael Bach's website allows you to more easily switch between both directions of rotation by placing eyeballs on the figure. For example, right now I think she appears to move counterclockwise if she is viewed from above, so let me hit clockwise.

Now her eyes help her reverse, and now she is moving clockwise from above for me. Very, very cool, but now let's talk about the Thatcher Illusion. Right now you probably already think that her face looks a little strange because if you turn it around you will see that it is actually really strange. When she faces all cognitive tools upside down. We have to analyze what it looks like and what it does well. They're not that good at doing her job, but enough about the faces. Let's talk color, the Exploratorium has a fantastic website full of interactive exhibits.

This one I just discovered this morning is actually a vanishing point illusion. You have a green spot with a smaller blue spot in the middle. Now it is very important for this illusion to work that you stare at that blue dot and do not move your eyes. Actually, keep your eyes as still as possible and the blue dot will disappear until you move your eyes. The moment you move your eyes, it will reappear in the frame. Now some people find it easier to just look at the edge of the square keeping their eyes completely still until the blue disappears, but the moment you move your eyes to anything, the blue dot appears.

That's because when your eyes move, they gather new information and the blue dot that was forgotten because it was not important reappears because it now falls on new cells in the retina. This illusion came from reddit and I love it. We have points that appear and disappear. The question is: are you and I seriously asking this? Do you think the illusion of motion created here is two dots going up and down or two dots going side to side, or are dots moving clockwise or counterclockwise? clockwise? If you try hard, you can change your perspective just with your own will.

Oh yeah, I just did it. Now I see them coming and going. What's really interesting is that if you slow down the frame rate of this animation, it becomes even easier to switch between the different perspectives. Fortunately, the creator of the gif provided one with much slower movements and here I find it incredibly easy to choose exactly what I want the dots to do for me. When it moves faster, I honestly can't imagine them moving in any kind of clockwise or counterclockwise rotation, but when they are slow, I can do it at will at the same moment in time.

I decide that I want to see it, see the movement that I want. to see. Now let's talk about hinged tessellations. A mosaic is a mosaic of figures that can cover a plane indefinitely. But a hinged tile is one where the actual tiles can rotate and re-fix in a new position. So this is what I love about this Al Grant site. Not only will you learn about tiling and tessellations, but you will also learn how they can be hinged together and there is even a hinged tessellation generator. I can choose between trapezoid and cyclic. Let's do the trapezoid well, let's do the cyclic first.

A cyclic quadrilateral is one whose points all lie on a circle and I can choose where I put them. With a square the result is quite trivial, but you can choose all kinds of walnut shapes and then once you're happy with what you have, go ahead and articulate them and look you've created a hinged mosaic. Great job. A brilliant organization made this episode possible and I love them. They are in line with what Vsauce stands for: learning and asking questions. On the site you can take courses that question you and you may not understand them well.

Certainly not, but by getting the questions wrong I think you learn more, so let's dive into the tessellations page. You can learn about them. Now here we have a question: If spread to cover the plane, which of the patterns below is a regular tile? Very good. Well, I think I should have read all the information before this question, but I'm going to go with D. Oh, maybe they're all wrong, but look what it says below is wrong. Alright. Being stumped is part of learning, and I totally agree! That's what I love about shiny.org. We're also offering a special offer to the first 36 people who sign up at shiny.org using the link below.

They'll get 20% off your annual subscription, so check it out. Thank you for supporting Vsauce. Thanks for supporting DONG and as always thanks for watching.