Just turn the image upside-down and the wine glass will be seen standing outside the tray (restore the picture). This illusion was invented by G. Sarcone for a science festival on optical illusions.
The Authors Gianni A. Sarcone and Marie J. Waeber, designers and writers, are specialists in creative learning. They create and invent educational manipulatives and thinking games which help teach mathematics, visual and plastic arts.
Just turn the image upside-down and the wine glass will be seen standing outside the tray (restore the picture). This illusion was invented by G. Sarcone for a science festival on optical illusions.