Test your observation skills with this hidden object challenge designed to reveal how quickly you can notice subtle details ...

The new technique generates an image (top right) from the speckle pattern created when light from the coloured numerals (top left) is scattered by the mostly opaque surface in the middle. (Courtesy: M ...

Optical illusions never seem to get old; one after another, the simplest pictures transform into a hard visual task for internet users. One of the puzzles that went viral is the one testing people's ...