Editor's choice: Sailfish swords, body heat power and an Antarctic mystery solved
A round-up from the scientific and technical journals.
How sword fishing works
Sailfish, powerful ocean-going predators up to three metres long, sport a deadly sword-like bill. UK-based biologists have now worked out exactly how they use them. The bill is slim enough that the sailfish can slip it into a school of sardines without them noticing it. At such close proximity, the sardines can’t react quickly enough to escape when the sailfish then slashes at them with its bill, securing the sailfish a guaranteed meal. Details of the study can be found here.
Bodyheat-powered wearable technology
Smartwatches, wrist-fitted fitness trackers and other wearable gadgets that interact wirelessly with your smartphone are a rapidly emerging area of technology. But they are currently limited by the small batteries that can be squeezed inside the devices. Researchers at KAIST in South Korea have developed a thermoelectric generator, encased in a lightweight flexible glass fibre, that could help power these devices by harvesting energy from body heat. More information here.
Solving the mystery of sounds of the Antarctic
Scientists have finally tracked down the source of a strange “quacking” sound that has puzzled Antarctic researchers for more than half a century. The sound, heard in the waters of the Southern Ocean each winter, is made by Antarctica's minke whales. Scientists made the discovery after placing acoustic tags on one pair of the whales to track their feeding habits. The finding, reported here, gives researchers a new way to track the movements of this little-studied species.