Where No Fuel Has Gone Before

Esther Inglis-Arkell describes the “Woodward Effect,” a potential solution to the biggest problem facing space exploration: the need for “a source of propulsion that can be accessed anywhere, without needing an outside source of matter or energy”:

[The Woodward Effect] proposes that we can, essentially cycle a group of particles through a loop again and again, and they will change mass. We can pull on them when they’re at a light point in their mass, and push them away when they’re heavy. It will be like grabbing a balloon and pulling it towards you, only to have it change into a bowling ball as it reaches its nearest point and you push it away again. You’ll feel an overall push outwards.

But not everyone agrees that the idea would work:

Many scientists dismiss the very idea — and Einstein was one of them. Others are considering the utility of the idea, and looking into the practical benefits that we could get from it if it’s true. The Woodward Effect has been tested multiple times. While some tests indicate it might be even greater than Woodward himself estimated, other tests are muddy and inconclusive.