By combining ultrasound with a concept called nonlinear acoustics, you can create sound that stays silent until it reaches a ...

"The sound waves create microscopic bubbles in a diazonium salt solution, which then collapse rapidly, creating tiny bursts of heat and pressure," Associate Professor Darwish said. "This triggers ...

sound waves cause air particles to vibrate back and ... between the wave direction and the normal – an imaginary line drawn at 90° to the barrier. The diagram below shows a water wave reflected ...