(Nanowerk News) Acoustic waves in gases, liquids, and solids usually travel at an almost constant speed of sound. So-called rotons are an exception: their speed of sound changes significantly with the ...

The metamaterial structure the team designed is made of a single linear elastic material. (Courtesy: Yi Chen, KIT) An unusual type of sound wave that can travel backwards in space and has previously ...

If it were easier to pronounce, you could call it a "rellor retsaoc." That's "roller coaster" backwards, and Six Flags Over Georgia is going forward with plans to make its Great American Scream ...