Boeing has filed a patent application for what seems like an impossible technology: 3D printing a levitating object. Yes, it's real - the process would involve using magnetic fields or acoustic sound waves to levitate an object so that multiple print heads can surround it and add printing material from all sides. The object can also be rotated in midair, using additional magnetic fields. If the idea comes to fruition, it would eliminate many of the current limitations of 3D printing, allowing the rapid manufacture of objects of any shape or size. Read more at 3DPrint.com: http://3dprint.com/121633/boeing-lev...g-3d-printing/