My possible explanation for gravity:
Gravity is caused by the expansion of space imparting a force on matter. Space naturally expands; even the space contained within a massive body such as Earth or an atom is expanding. When the space attempts to expand into the area occupied by matter, it is unable to do so but I believe it imparts a force on that matter that we call gravity. If this is true it would negate the necessity for gravitons or gravity waves which, for which IIRC no direct evidence has been found.
I also think that space would resist its own expansion so that the force of gravity would actually be related to the amount of space in any massive body. Imagine the Earth compared to a black hole. There is no space in a black hole (or very little) while there is a lot of space in the Earth in between molecules and within atoms, etc. Therefore a black hole's gravity is near the maximum possible gravity possible in our universe (no space [edited] is present.)
I'm no mathematician or formally educated scientist but I am familiar with the properties of the universe and most physics and logically, it seems that all the formulas currently in place for gravity would still be valid. Gravity would depend on what I call "spacial density" as opposed to the amount of matter but it would still work similarly if not exactly the same as what we observe now.
I am curious, mathematics-wise, how this would work on a galactic scale with the issues relating to spiral galaxies that only the existence of dark matter can resolve (i.e. spiral galaxies are spinning too fast to maintain their shape unless dark matter exists.)
I would very much like to hear other opinions and comments about this alternate idea for gravity.
Thank you for your time.