AN OPTICAL illusion fan has revealed a clever trick that will really mess with your brain.
The eye-teaser looks simple on the surface until it starts moving.
@pickoverCan you see the trick?[/caption]
It shows two rectangles – one is yellow and the other is blue.
They slowly move across a black and white vertically-striped screen.
It appears that one is always ahead but apparently that’s not the case at all.
If you wait until the end, the background will change to grey and show they’re actually moving at the same time all along.
So why does it look like one is always ahead of the other to begin with?
Cliff Pickover, who shared the illusion on Twitter, linked to a scientific paper which apparently explains it.
“Illusions show that contrast affects apparent speed,” the research is titled.
It’s officially known as a stepping feet illusion.
And it basically comes down to a contrast change that happens between the black and white stripes.
As Marco Bertamini’s Programming Visual Illusions for Everyone book explains: “A dark object will have high contrast against the white stripe and low contrast against the black stripe.
“The opposite is true for a light object.
“As a result a motion with constant speed may appear to speed up and slow down.”
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