Here's a little science for you, /co/
Gravity is a phenomena best described as the influence mass has on spacetime.
https://www.youtube.com/watch?v=MTY1Kje0yLgYou, along with everything on this planet, bends spacetime to a certain extent. Anything with mass usually does.
This can be used in a variety of ways.
For one, it can be used for FTL travel. If one were to manipulate gravity in where a high concentrated field of mass were to be created virtually in front of you at all times, it'd contract the space in front of you, shortening it.
If you were to create a form of negative mass, as in, a mass with less than 0 mass (I know, sounds redundant) then you'd essentially be creating "anti-gravity". Instead of contracting spacetime, this extends it, creating longer distances. If you were to place a field of anti-gravity behind you, and a field of high mass in front of you, you'd be accomplishing what most scientists theorize would be a way of superluminal travel without the worries of creating an acausal event or paradox.
And depending on whether you believe in Brane Theory, gravity (or supergravity) is the STRONGEST fundamental force. It has jurisdiction over all other fundamental interactions besides maybe electromagnetic forces. But that's a maybe.
