sound

Imaging an unborn fetus and and spotting a lurking submarine could both become much easier with the world's first acoustic hyperlens. The device manipulates imaging sound waves to provide an eightfold increase in the magnification power of technologies such as ultrasound and sonar.

Observing a star up close (putting aside for a moment how you’d get there or withstand its heat) is probably like sitting beside an enormous silent fire. Sounds—which are simply pressure variations in a medium such as air or water—can’t propagate in the vacuum of space, so the roiling surface of a star would make an impression on the eyes, but not the ears.

Technological advances have brought audio recording a long way over the past several decades, but, as with so many things, microphone recording is limited by the very technology that has pushed it forward. In this particular case, that limit is the diaphragm that converts sound into electrical signals by measuring vibrations made by incoming sound waves. Because each diaphragm has its own characteristics, all microphones are not created equal; and because the sound waves are converted by these diaphragms, there is always some degree of mechanical interference with the sound.

For blind people who can't perfect the system of clicks and whistles designed in Spain for human echolocation, researchers at the University of Bristol in England have created a new solution: a helmet that automatically transforms a map of the surrounding area into sound.

Thanks to a new approach to one of microfluidics' biggest challenges -- how do you propel fluid in a number of directions simultaneously without the clutter of myriad electromechanical valves and pumps? -- we could be closer to seeing our smartphones double as home flu kits. Credit goes to a team of chemical engineers at the University of Michigan for coming up with the innovative system, which uses music to control the fluid.

This has been a good week for sonic physics. First came reports that scientists used sound waves to create a sonic black hole. Now, it seems that a different group of scientists have used specially calibrated sound waves to create something almost as cool: a sonic laser.

The lasers most people are familiar with are formed from beams of light with identical wave structures, added together to form one giant, coherent wave. The saser, created by scientists from the University of Nottingham, England, works the same way, but with correlated sound waves instead of light waves.

The world certainly isn't simple, and trying to express real-world dynamics in the form of an equation has long been a challenge. Realistic computer-simulated sound has been particularly tough to get right, and some of the hardest dynamics to recreate have been the movements and sound of water.

Scientists at Cornell have now announced a system that can look at a 3-D motion rendering of water--waves, drops, anything--and algorithmically create the dribbles, gurgles and plops it would be sounding, were it in fact real.

Researchers at the Lawrence Livermore National Laboratory in California successfully converted sound waves to light radiation by reversing a process that transforms electricity to sound, which is commonly used in cell phones. This is the first time that sound has been converted to light. The findings, which were published this week in Nature Physics, could improve how computer chips, LEDs, and transistors are made, and also have applications in ultrafast materials science and terahertz radiation (T-ray) generation.

The research team initially predicted that the conversion was possible around a year ago, using computer modeling, and has been trying to confirm it in the lab ever since.