"jeffbert" wrote:fafner:My understanding of the physics says that gravity is tied only to mass; but I could be wrong.
Yes it is tied to mass, the same way as electromagnetic force is tied to charge. More precisely, it is also tied to speed because mass goes up with speed, but at the end it is more tied to the overall energy rather than mass alone. As we currently understand it, gravity works in a similar way as a rubber blanket where objects tend to push through it and as a consequence are attracted one to each other. Putting an object doesn't immediately distort the blanket, the distortion progressively reach every point. Of course on the blanket it looks immediate, but in outer space it may take a lot more time
The progression of the distortion may be waves, but ultimately it depends on what is gravity, as scientists aren't even sure it is a fundamental force.
I'm on Fanfiction.net as Tetsuwan Penguin. Please check out some of the other stories I've written! 
