yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

STOPPED CLOCK ILLUSION


2m read
·Nov 10, 2024

Hey, Vsauce. Michael here.

And today I've got a brand new episode of Vsauce Leanback. You can click this annotation or the link at the top of the description to start it, and then you can just lean back and the autoplay playlist will bring the knowledge right to your brain. As you already know, it doesn't really work on mobile phones yet, so wait until you are in a better position to lean back.

In the meantime, let's get saccadic. No, not psychotic; saccadic, referring to what is known as a saccade—the quick movements that our eyeballs make when we move from one object to the other. As you may remember from a previous Leanback, some animals, like most birds, cannot move their eyeballs.

And so, to look from one thing to another, they have to move their head really, really fast. To keep the world from being blurry when their bodies move, they have to keep their heads completely stationary. But here's the neat thing about saccades. When our eyes move, there's a quick blur between one destination and the other.

And that blur is completely incomprehensible to our brain. So what our visual system does is erase it from our memory and instead replace that little fraction of a second that our eye moved during with the very next thing we see. This leads to a really amazing illusion called 'The Stopped Clock Illusion.'

You may have noticed this before if you've ever been in a room with a clock with a second hand, like in a classroom, darting your eyes back and forth, waiting for class to be out. Now here is what happens. Right when you dart your eyes to the clock, that very first second—that very first movement of the second hand that happens when your eyes reach it—seems longer than every other second afterwards.

Look away from the clock and then look. And that first second will seem to linger, as if time itself has stopped. The reason for that is that your brain replaces the time it took for your eye to go from here to the clock with an image of the first thing you saw, which was the second hand.

And so, that little fraction of a second of time is added to the length of time it takes the second hand to move. What's really mind-blowing about this entire effect is that it happens all the time. All day, as you look around the world from one point to another, that little fraction of a second that your eyeball was moving is lost, and your brain just replaces it with the very next thing that you see.

Now, it might just be a tiny, tiny amount of time, but over the course of an entire day, those little fractions of a second add up to almost 40 minutes. 40 minutes of every day that you're awake are lost because our eyeballs move.

And as always, thanks for watching. So what are you waiting for? Click here to start the Leanback or click the link at the top of this video's description. You know what? I totally never say this... Yeah, I'm totally heterosexual, but... You are really attractive!

More Articles

View All
Khan Academy Talent Search 2016
Hi, this is Sal Khan, founder of the KH Academy, and I just wanted to announce our second annual Talent Search. As you may know, KH Academy, we’re a non-profit with the mission of a free, world-class education for anyone, anywhere. Part of that is creatin…
Divers Find a Wreck 90 Meters Down | Drain the Oceans
It is a very deep dive with a lot of repercussions that come up too fast. Bubbles would form inside your blood, inside your tissues, and cause ill effects. To get to 90 meters, you’d be looking at 4 or 5 minutes to get down there. It’s very dark because y…
How much I spend on dating
What’s up you guys, it’s Graham here. So, I have been blown away with how much demand there is for legitimate frugal dating advice. And of course, with that, everyone wants me to talk about how much money I spend dating and wants me to go over my dating b…
Sources of genetic variation | Inheritance and variation | High school biology | Khan Academy
In this video, we’re going to talk about sources of genetic variation, which is key for evolution and natural selection to happen. Just as a little bit of a primer: natural selection, you can have a bunch of different organisms with different genetics, di…
Some Surprising Things
Hey, Vsauce. Michael here. What’s normal? Are you normal? Well, today let’s bathe our brains with those questions and scrub down with things that are surprising and counterintuitive. What does it mean to be normal in the first place? Well, maybe it just …
Worked example identifying experiment | Study design | AP Statistics | Khan Academy
So we have some type of study described here. I encourage you to pause this video and think about whether this is an observational study, an experiment, or a sample study. Also, think about whether it was conducted well. All right, now let’s do this toge…