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Inkless science

Science LOVES questions: just like kids do.

Optical Illusions*

Just so you know, all you kids out there who have trouble spelling words:

I keep accidentally typing: "illustion" instead of "illusion" - and having to go back and correct it.

So we ALL make mistakes! I just wanted you to know.

In 1860, physicist and scholar JC Poggendorff was the editor of a scientific magazine. He got a letter from an astronomer named F. Zöllner, who had noticed a similar optical illusion (now called "Zöllner's Illusion") where short diagonal lines seemed to come together. (Zöllner was looking at fabric at the time.) Honestly, the places you can learn things from!

Either Poggendorff was REALLY bored, or he was REALLY into optical illusions, but etiher way, he gave the matter some thought - a LOT of thought - and came up with his own version, now called, what else?

Poggendorff's Illusion.

diagonal line illusion

Does this diagonal line go straight through the rectangle, or does it take a little hop first?

Move your mouse over the picture to check.

Why do YOU think this illusion works?

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