Letter writer number 4 is on the right track.If you read the end of his letter where he talks of capturing electromagnetic waves in the torus. this is the basic idea that will help create a wormhole or clean space . also when you capture these electromagnetic waves in the torus the torus gains the energy of the wave it has coupled with. The faster your torus is traveling the higher frequency the waves will appear do to dopler shift. but the main point is that you will have cleared a hole in space as your toroid couples with waves and you will have gained energyand the wave at the point in space your toroid is in will now be part of your toroids energy.