They would need to constantly produce thrust in space with an array of lightweight devices. If these things are proven and developed then our world radically changes from an ordinary world into a Star Trek with impulse drive and the equivalent of antigravity. The propellentless propulsion would offset gravity.

In the new video, Charles Buhler also describes that this would open up possibly limitless energy. The energy aspect is one of the reasons that physicists do not believe this is possible. It would violate fundamental laws of physics. There is the belief that it would be a perpetual motion machine. It might make a perpetual motion machine but if we figure out what is happening then it could like wind and wind turbines. We could tap into another source of energy with different rules and limits.