Imagine, a tube magnetically charged.In this tube you have a transport device which also is magnetically charged(I HOPE YOU'RE STILL FOLLOWING ME HERE). So now you have a floating object inside the tube. What if you'd change the magnetic charge of the tube so that you create a thrust. If you'l change the magnetic charge so fast, with the speed of light for example, you have created an object that moves with the speed of light. If one would do this expirement in a place which has a zero gravity surrounding, like space, you have an on-gowing thrust. Therefore one can travel with the speed of light.