Is it a bird? No, it's definitely a plane: NASA unveils extraordinary ideas for the aircraft of 2025

They are the sort of striking images that wouldn't look out of place in a scene from a sci-fi movie.However, one of these could soon be the face of modern aviation with the unveiling of a new generation of passenger aircraft.NASA has revealed three concept designs for quiet, energy efficient aircraft that potentially could be ready for flight as soon as 2025. Future flight? Boeing unveils