SLOW BUT SOLAR: The carbon fibre Solar Impulse plane has the wingspan of a 747 but only weighs as much a Honda Prius. Its 4 turboprop engines are powered entirely by batteries and solar panels. This year the plane will fly from California to New York, maintaining an average altitude of almost 9,000 metres where the engines operate with maximum efficiency. The plane travels at only around 80 Kph. The plane itself could make the trip non-stop, but with a single pilot aboard, the flight will be broken up into 5 sections. At that speed the flight from Auckland to Sydney would take around 27 hours.
NEW SALTS: NASA's Aquarius/SAC-D spacecraft has been gathering salinity data from the top 2 cm of the oceans. Now the data's been verified NASA have released a map that shows how salty the oceans are around the world. Interesting items include the large patch of freshwater that appeared in the eastern tropical Pacific in the winter, and the large patch of highly saline water across the North Atlantic. That variation in salinity must have a huge effect on plant and animal life in the oceans.
WAVE A LETTER: Tapping out letters on the cramped keyboard of a smartphone is always challenging, so researchers at the Karlsruhe Institute of Technology looked for an alternative. The airwriting glove lets wearers write letters in the air, as if using an invisible board or pad. The system adds sensors such as acceleration sensors and gyroscopes to a thin glove. As the wearer moves their hand, writing in mid-air, the glove records the movements and sends them wirelessly to a processor. The processor distinguishes between movements such as drinking coffee and actual writing, then decodes the writing into text. Now the scientists are working on refining the writing recognition and making the whole system smaller. Hmm, printing or cursive?
TWO FOR ONE: Researchers at MIT have demonstrated that graphene is highly efficient at generating electrons when it absorbs light. Unlike materials like silicon and gallium arsenide, when graphene absorbs a photon it generates multiple electrons capable of driving a current. The other materials generate only a single electron. That could mean graphene has potential in solar cells and for light sensors such as night vision goggles. Unfortunately it's all pretty much a concept just now, but further research should lead to some practical applications. What can't graphene do?
LET THE SUN SHINE IN: Ivanpah in California is nearly ready to start work as the world's largest solar thermal plant. The power system is built on federal land in the desert, covering more than 1400 hectares. More than 300,000 mirrors are controlled by software to track the sun and focus sunlight on boilers on top of 3 towers, each 140 metres tall. The sunlight heats water to create steam and generate electricity. The plant should supply the power needed by 140,000 homes. That's about 100 homes per hectare.
