Why does the first second seem longer when you suddenly look at a clock?

Question

Don’t even know should I flair this as physics or biology lol

In: 1239

Answer 1

This is actually super interesting, and you are correct that it is Biology. The effect is called “chronostasis”, and it will also probably change how you think about how you experience reality!

Humans aren’t that great in visual acuity but we can distinguish colors fairly well compared to other animals, and we are *amazing* at visual processing. We may not be able to see tiny details in the distance like a hawk or operate in dim light like a cat, but we can form a 3D mental model of the world like no other. There is speculation that this evolved along with the ability of humans to throw weapons at stuff. But whatever the reason there is significant brain resource devoted to processing visual stimuli from our binocular vision.

However, binocular vision requires both eyes to focus on one spot. Our eyes can follow a focused target as it moves, but they really can’t smoothly sweep across our visual field. That is just too hard to process, so our eyes naturally jump from point to point. BUT, when our eyes are doing that jump (called “saccades”) our brain just doesn’t even try to understand the blurry mess of sensation that comes in. In essence you momentarily go *completely blind*!

But you don’t *feel* like you went blind, right? Your vision doesn’t go black or anything and it seems like you could see that whole time. The reason is because our brains fill in the lag while our eyes are moving, making it seem like instead of being blind for that time we were seeing something. What is really weird is that our brains fill it in with **what we see when they stop**! Yes, our brains go back and edit our memory of a split second ago to make it seem like we were looking at our new point of focus the whole time our eyes were moving to actually see it!

This is what is happening when you look at the clock’s second hand. When you glance over to the clock your brain will tell you that you were looking at it for longer than you actually were, adding that time while your eyes were moving but you didn’t actually see the clock yet. If the second hand was moving while your eyes were then your brain will think the second hand was in its new position for longer than it actually was. Based on that flawed memory it will seem like the second hand stayed there longer than a second! That is why the first second sometimes seems longer than it should when you glance over to the clock!