Researchers in the US, funded by the US military and the National Science Foundation, have managed to turn air into an "optical fiber." This breakthrough allows the scientists to turn thin air into an optical waveguide, allowing for much better transmission of lasers through free space -- much in the same way that glass and plastic waveguides allow for efficient transmission of laser light over long stretches of optical fiber. As you might have guessed from the US military's involvement, this could be big news for laser weapons -- but there are repercussions for laser-based communications and scientific research as well.