Millions of people around the world don't have a source of light once the day grows dark. The

aims to play a part in bringing light to the night. Inside the ball is a small pendulum that harnesses kinetic energy as it moves during play. That turns a generator that feeds a rechargable battery. An LED light plugs into the ball for when play is done. 30 minutes of play can supply 3 hours of light. The waterproof foam ball doesn't need inflation and can't be deflated. It has a 6 watt output capable of powering the included lamp for more than 72 hours. Nice work: play during the day and enjoy the light at night.

GORILLA IN THE BACKGROUND: People wandering across the background of a video can be really annoying. But provided the video background is static researchers at Max Planck Institute for Informatics can remove the intruders with some very clever software. The system uses other frames of the video to establish what should be visible, then uses smoothing techniques to make colour consistent. While the software had some problems with complex scenes, it was often very successful. You just can't ever believe what you see.


EYE BEAMS: Could plastic retinas help you see? Scientists at the Italian Institute of Technology have developed a flexible organic polymer that converts light into electrical stimulation without needing an external power supply. In a study they grew neurons on the photovoltaic polymer, then placed damaged retinas on a piece of glass coated with the polymer. When they shone a light onto the retinas, it caused neuron activity similar to that in an undamaged retina. Daylight levels of brightness caused a good response, though dimmer levels didn't work well. Eventually this technology may help people with retinitis pigmentosa and some forms of macular degeneration. There will be many people wishing them good speed on that.

KEEP PUMPING: People waiting for a liver transplant have a tricky time of it. When a donor liver is found it's packed in ice and chemicals then rushed to its destination. But all too often the liver deteriorates in transit and can't be used. A new device from the University of Oxford should improve the chances of livers arriving in good shape. It keeps a donated liver at body temperature for 24 hours or more, and supplies it with blood, sugar, oxygen and nutrients. In some tests livers survived for 72 hours. The device works like a human body, pumping blood and nutrients through the liver and monitoring it for changes. The scientists say the device could be modified for other transplantable body parts too. In hindsight an artificial body seems a bit obvious.

FROM RAGS TO RESIN: Photovoltaic solar panels are a good source of clean energy, but unfortunately components of the panels are generally made from petroleum products. BioSolar's components made from renewable cotton derived from rags and resin from castor beans can replace petroleum-based plastic panels and save the manufacturer money. It's encouraging to see renewable sources gradually replacing petroleum, and at least rags aren't a food source.

Miraz Jordan, knowit.co.nz