When you quickly move your eyes to focus on the seconds hand of an analogue clock, have you ever noticed that the first second you see actually seems to linger for a slightly longer time? Yes, it does. And there’s a reason why it happens.
When you rapidly move eyeballs to focus from one point to the another, it’s called a Saccade. If you ever try doing this rapid movement with a camera, a motion blur occurs in between the first point focus and the last point focus.
Unlike cameras our eyes (work closely with the brain) has a built-in mechanism to erase this motion blur. The brain erases all the motion blur during those few milliseconds and replaces the motion blur frames with the final image in the end.
This is why you see the longer first second when you quickly focus your eyes on the seconds hand – the stopped clock illusion or chronostasis. This also explains why you can never see your eyeballs moving when you try to spot their movement while staring at your own eyes on a mirror.
Michael Stevens from Vsauce explains…
Broome is a coastal town in the Kimberley region of west Australia. Every year when all the conditions perfectly fall in place, a very interesting and brilliant natural spectacle occurs. They call it “Staircase to the moon“. It indeed looks like stairs reaching to the moon. Thousands of tourists and the local people gather to watch it happen.
For it to happen the weather, sunset, moonrise and the tide conditions all need to be perfectly right. Before I tell you what happens there, look at a picture of this natural phenomenon. (Or it won’t seem very interesting if I tell you about it first).
This happens only during the low tide at the coast when the moon is rising. During the low tide, the mudflats get exposed and the rising moon creates this mesmerising reflection on the sand.
The natural phenomenon can also been seen from other coastlines at Onslow, Dampier, Cossack, Point Samson Peninsula, Hearson Cove and Port Hedland.
You probably know the static Ebbinghaus illusion – where a circle appears bigger around smaller circles even when it is of the same size. It’s static because it works without moving. Well, if you don’t know, you should because it helps you lose weight in a very subtle manner.
A slight variation involving movement of the Ebbinghaus illusion won the best illusion award for the year 2014. Yes, there are annual awards for the best illusions (I never knew that!). This one which won the award was submitted by researchers from the University of Nevada Reno.
The new variation is called the Dynamic Ebbinghaus effect. This is what happens in it…
There’s an arrangement of circles, exactly like the Ebbinghaus illusion, but there’s just one of the sets from the static illusion discussed above. While this arrangement of circles move, the central circle remains of the same size and the surrounding circles change in size.
Now, if you look into the central circle, you’ll see that it changes size too. In reality, it doesn’t. This effect is weaker when you look directly into the central circle. To make it more pronounced, you can shift your focus to the side and look at it through your peripheral vision. It’s totally mesmerizing. No wonder it won.
It works even when you know about it.