I know “not much” about science but maybe science needs people who think outside of the restrictions governed by the laws of physics.
If you could make an object with a force of gravity that was small. Encapsulate it. Put things in an orbit around it and somehow tap into its energy have you not just created a gravity piston or generator. ??
If you create something with gravity of at least 1.1. Earth being 1 and made it portable do you not have something that is an antigravity drive?
And if leaving earth orbit takes so much energy going straight up why not slingshot around Earth. But then again you would need a craft so fast to take advantage of the earths elasticity in the gravitational field it would be too difficult to capitalize on it.
I then thought a bit about centrifugal force to generate artificial gravity as in https://en.m.wikipedia.org/wiki/Artificial_gravity and using it in conjunction with nanoscopic pressure cells that can be used to generate energy through application of pressure.
Can you not spin a hollow tube with weights in it and nanoscopic pressure cells and generate electricity and would that be more efficient then the current wind turbine generating technology we used today?