BTW I have a wacky scifi theory on the EM Drive aforementioned.
Awhile back I was brainstorming for a universe sim game I'll probably never get to make, idea being a sublight speed explore-the-galaxy kind of game where the galaxy would be simulated over large amounts of time.
When thinking about the tech tree I thought one of the discoveries could be a proving out of the holographic principle, and evidence that the entire universe is a simulation (which in this case would be true). With that in mind I started thinking of ways to exploit that.
One of the things I ran across is the Beckenstein limit or bound. This is an idea that only a finite amount of informational bits can be stored in a given area. I thought maybe approaching this bound in a simulated universe would cause the same sort of warping of spacetime that gravity produces.
So I thought it would be clever / fun to have advances in computing start to affect nearby space, maybe even decaying the orbits of planets.
Anyway, one of the ideas I had was for a drive that transmitted and displayed dense information to an area to create this warping effect.
The EM Drive could work in a similar way if the simulation's bits required to represent the clumped up resonating microwaves approaches the Beckenstein bound.
Bekenstein bound - Wikipedia, the free encyclopedia
Holographic principle - Wikipedia, the free encyclopedia