Heat is not supposed to behave like this. In everyday life, warmth seeps and diffuses, spreading from hot to cold in a slow, smearing process that never looks anything like a crisp sound wave. Yet ...

Sound is usually treated as the most familiar of physical phenomena, the background noise of daily life rather than a ...

Ordinarily, light transmits the same in both directions: if I can see you, you can see me. Now, however, researchers have created a device that uses travelling sound waves to break this symmetry, ...

Helium leaks are hard to detect. Helium is odorless, colorless, tasteless, and does not react with other chemical substances.

Although few people ever get the chance to travel at the speed of sound, it is an alluring flight goal and an impressive technological feat. Though average people have flown at high speeds on ...

Upper limit: a US Navy F/A-18 travelling near the speed of sound in air. The white halo comprises water droplets that have condensed from the air because of the sudden drop in pressure behind the ...

Students learn how sound waves are produced and transmitted. Students learn how sound waves are produced and transmitted and how frequency is related to pitch. The speeds of sound in different media ...

Daniel Barenboim: Sound has several very interesting aspects, I think, worth observing. One is duration—that there is a connection between sound and time. But before that there is a connection between ...