I was given this little optical illusion and its quite clever but I wondered if it had a name. Basically it’s a piece of paper with a sort of circle design on both sides. Inside this design there are letters. On one side ICED COKE and on the other RUM & WATER. You also get a clear plastic rod. When you put the rod up to the rum and water is gets flipped. When you put it over the iced coke it stays the same.

If anyone has any idea what I am talking about and knows the name I'd be interested to know. Maybe it doesn't even have a name.

I'm interested in this illusion. Where did you get this?

I usually do this with the stem of a wine glass and write "CARBON DIXOIDE" on a piece of paper. "CARBON" is written with a blue pen and "DIOXIDE" with a red. I explain (this is great for engineers) that different wavelengths of light get bent differently by glass. When they put the stem over the word only the blue word appears upside down.

/Tomas

A party trick for when the wine is flowing just as TomasB said above.

A good trick to try on a group of drunken scientists.

HOW TO DO THE TRICK
Explain that just as a glass prism splits up the different colours of white light, when different coloured light passes through glass, it is also affected to an extent that depends on its colour.

Write the words CARBON DIOXIDE on a piece of paper, CARBON in red and DIOXIDE in blue. Put the paper close behind the stem of a wine glass, and look at the words through the stem. The red letters turn upside down, but the blue ones don't. So is the glass affecting the red light more than the blue? A good trick to try on a group of drunken scientists

HOW IT WORKS
You weren't fooled, were you? This has nothing to do with the different colours of the words, or of red light being bent more or less than blue light.

The stem of the wine glass turns both words upside down, but because DIOXIDE is symmetrical about a horizontal line, you don't notice that it is upside down—it looks just the same either way.

See this and other optical illusions at http://www.grand-illusions.com/

Robin_martin ,

You must have gotten that illusion from me or someone whom I dealt with. The idea is VERY clever. I got them wholesale from somewhere.

Supreme Magic used to sell them as Rum & Water and that's all I know. I still have half a dozen of them in my bag.

It has been marketed as "Vision Tester."

Steve

I saw this at the FUNARAMA last year for sale by Scott Correll ( I think and Spelling is a question) He said he had been selling it for years and had no Idea how it worked...I knew and told him. It is a fun little puzzle..

Jeff