You can prove gravity?
Just to be clear, you are talking about the theory of universal attraction, with the classic formula
So how would you prove universal attraction? And how this gravity thing get from one place to another? Is it particles? Is it waves? How fast does it travel? How do you know it always works? It sounds like Gravity is just a theory and an incomplete one at that. And since you can't prove it, its not real, right? Seriously, there can be all kinds of details about a theory that need to be worked out after its clear that it works in general in our local area. Sometimes new conditions will be observed that make changes (as happened with gravity after 1905) but even then the new theory still has to explain the old conditions too. The basic principle of evolution, that life evolved on earth from the simple to the complex looks pretty darn secure.