Sandrine Ceurstemont, editor, New Scientist TV
Ever been mesmerised by patterns of light at the bottom of a swimming pool? Now you could take control of the effect to display your own designs.
When the sun shines on a pool, the water's curved surface reflects and refracts light rays to produce a pattern. By reverse-engineering the process, known as caustics, Mark Pauly from the Swiss Federal Institute of Technology in Lausanne and colleagues came up with an algorithm that allowed them to make a plastic panel that casts Alan Turing's portrait on a wall (see video above). "You can think of it as painting with light through the form of an object," says Pauly.
The team has been working with architects to see how their system could be used in buildings, for example to shape shop windows so that they display images on the floor. Objects like wine glasses and perfume bottles could also be designed to cast patterns, or the technique could have more technical uses in optimising the way car headlights illuminate the ground or for better reflectors.
For more on how caustics could change your surroundings, read our full-length article, "Engineering light: Pull an image from nowhere".?
If you enjoyed this post, watch a 3D-printed magic lens unscramble hidden images or see how an engraved plastic panel can display images.