DURHAM, N.C. -- Researchers at Duke University and Aalto University (Finland) have constructed a "meta-mirror" device capable of perfectly reflecting sound waves in any direction. The ...

Metamaterials researchers have created a thin plastic structure with geometric details allowing it to control the redirection and reflection of sound waves with almost perfect efficiency.

A REMARK has just occurred to the writer, on turning over the account of cognate phenomena in Rayleigh's “Theory of Sound” (vol. 2, § 270), which seems to be of weight in this subject and may indeed ...

The film explores the nature of sound waves, demonstrating how sound travels as a wave through air, which acts as a medium. It illustrates sound generation using a loudspeaker, examines oscillation, ...

THE method of studying the ionized regions of the upper atmosphere by emitting small pulses of electric waves and recording the echoes reflected from the ionosphere is now well-known and is in ...

Sound needs a medium (solid, liquid, or gas) to travel. Space is a vacuum, lacking the matter to carry sound waves. No sound in space means no echoes. While a near-perfect vacuum, some sounds can be ...

Researchers have constructed a 'meta-mirror' device capable of perfectly reflecting sound waves in any direction. The proof-of-principle demonstration is analogous to looking directly into a mirror ...