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Gigantic Purple Slug

Optical Illusion ?

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At "first glance" the dots appear to be moving in all directions. But the only reason is all the dots look identical, and it's difficult to differentiate one dot from another. So one dot gets confused with another and it's direction gets confused too.

When you concentrate on a dot and follow it, yes they're going in straight lines.

But what a lame illusion. "Scientists are baffled"?? Someone just got paid for a vacuous article again....

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Me to, I stare at the red cross intently but still the dots only move in straight lines

I think we should start our own air traffic control business.

Just imagine, no extra runways or airports needed. Maximise your throughput with Purple Slug/SirGaz air traffic enterprises ltd and ultra high density flight control. And all for the price of only 10 billion quid.

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A couple on my hard drive.

Edward Adelson's checkerboard illusion. Squares A and B are the same colour.

adelson-checker-shadow-illusion.jpg

Similar demo with relative colour : the 'green' and 'blue' stripes are the same colour.

color_illusion.png

Edit: spelling.

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I'm not sure about the chequerboard on - I think thats a fool.

I confirmed the green blue one by putting bits of paper over the other stuff.

Here I've selected the B square in Photoshop, copied it, and pasted it next to the A square. No other editing involved.

adelson_checker2.png

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Here I've selected the B square in Photoshop, copied it, and pasted it next to the A square. No other editing involved.

adelson_checker2.png

Forgive me for being cynical, but that's not how I see it. I zoomed right in, covered up other squares and they look different. The green blue thing was very good though.

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Forgive me for being cynical, but that's not how I see it. I zoomed right in, covered up other squares and they look different. The green blue thing was very good though.

No harm in being cynical.

If you go over the squares with a colour picker in an image editing program you'll see that both squares have the greyscale value 120 (there will be some minor variations due to the jpg compression algorithm, but these aren't material).

I don't know for sure how you're going about the comparison, but if you allow ANY of the surrounding squares to become visible between tests then your brain is likely to be fooled.

Adelman's page on the illusion at MIT has some methods to prove to yourself that the squares are the same:

http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html

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No harm in being cynical.

If you go over the squares with a colour picker in an image editing program you'll see that both squares have the greyscale value 120 (there will be some minor variations due to the jpg compression algorithm, but these aren't material).

I don't know for sure how you're going about the comparison, but if you allow ANY of the surrounding squares to become visible between tests then your brain is likely to be fooled.

Adelman's page on the illusion at MIT has some methods to prove to yourself that the squares are the same:

http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html

i have had some beer, some wine (red and white) and some whiskey. I will have a go with the paint program idea tomorrow. Am sure you're telling the truth though.

edit to add - my heavily pregnant wife is stone cold sober and agrees they are different colours, out method was cover up all other squares with take away menus leaving only A & B there - I am going to have to do the paint thing now dammit

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i have had some beer, some wine (red and white) and some whiskey. I will have a go with the paint program idea tomorrow. Am sure you're telling the truth though.

edit to add - my heavily pregnant wife is stone cold sober and agrees they are different colours, out method was cover up all other squares with take away menus leaving only A & B there - I am going to have to do the paint thing now dammit

OK - I alt-prt scr into paint, cut out the A square and moved it over the B.

They are the same colour.

Pretty astonishing really.

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OK - I alt-prt scr into paint, cut out the A square and moved it over the B.

They are the same colour.

Pretty astonishing really.

Yes, can confirm they are the same.....cut two small holes in thick paper, placed over picture apart from the two squares so that they were visible through the holes and they are both exactly the same colour. ;)

gradient_illusion.jpg

Same principle as this.....Gradient illusion

Simultaneous Contrast Illusion. The horizontal gray bar is the same shade throughout.

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Yes, can confirm they are the same.....cut two small holes in thick paper, placed over picture apart from the two squares so that they were visible through the holes and they are both exactly the same colour. ;)

That's better science than I have read in learned journals. :blink:

It's called an "experiment". :huh:

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That's better science than I have read in learned journals. :blink:

It's called an "experiment". :huh:

Quite MrPin....you can't always believe everything you see, you have to some way prove it for yourself. ;)

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Quite MrPin....you can't always believe everything you see, you have to some way prove it for yourself. ;)

There is a lack of science in science nowadays! Everybody quotes each other's papers, like it's true, without trying it themselves.You can be my minister of cheese and church bells, when I declare independence! :lol:

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