Well That's Gravity

I was watching the latest Star Trek movie again and couldn't help but ponder the simulated gravity on the ships. At some point in the film the Enterprise gets caught in a gravity well. Gravity wells are caused either by large masses (like the earth) or singularities (whats left of a star after it dies which is more commonly labeled a black hole).

In order for the star ships to generate artificial gravity, wouldn't they have to be equipped with singularities in the floor? Of course, these singularities would have to be weak or they would tear the ship apart.

Or have they discovered a material that acts as a large mass but is as light as metal? This is highly unlikely but we are discovering new ways in which the universe works all the time.

Or does the ship's power simply generate enough energy to replicate gravity in the form of a bubble? In the show Enterprise, every ship had a "sweet spot" where gravity was weak. A generated gravity bubble would not reach every corner of the ship. This likely makes the most sense. Star ships would not have to generate as much energy as a sun to accomplish this. They would just have to generate enough power to maintain a gravity as strong as earth's.

Am I even close to figuring this out or should I just accept the fact that it is just a TV series which spawned movies?