Watching the waves IMS also has a smaller network of sensors to listen for explosions carried out underwater, just above the ocean surface, or below the ocean bottom. Sound travels very efficiently in water: Kiyoshi Suyehiro of the Institute for Research on Earth Evolution in Kanagawa, Japan, says a 20-kilogram test charge of TNT was detected 16,000 kilometers away. As a result, IMS has just 11...

Waves are familiar to us all--such as ocean waves, sound waves, light waves, and waves in a string. Waves may appear to be traveling or appear to be standing still. There are those being transported by a medium as for the ocean or in a guitar string and those that travel best through empty space such as the electromagnetic spectrum including visible light. Waves are a common means by which ener...

We develop a quantum theory of the nonlinear interaction between intense surface acoustic waves and electrons of a quantum well in the regime of moving quantum wires and dots. The quantum nonlinear interaction principally differs from the classical one. In a system of electron wires driven by an acoustic wave the sound attenuation strongly decreases with increasing the sound intensity. However,...