attraction between two objects?

Question

i do not get what means "gravity exists because matter exists"
like, i understand what is gravity. It is the force or attreraction between the object and the earth because we have gravitational force which pull everything towards the centre of the earth

but when we say the attraction etween two objects, for example, a pen and a book on the same table, there is still an attraction between the two. Why and what causes this attraction ?

i mean like, the attraction between the two objects on the same horizontal, bbut not the force that pulls them towards the centre of the earth.. yeah

Answer 1

gravitational force is in direct relation to the density of the mass in question........see Dr. Einstein,s theory,s.

Answer 2

All objects attract all other objects. The attraction diminishes by the square of the distance (e.g., something twice as far away has only one fourth the attraction). At the same distance, a more massive object attract more strongly, but that attraction becomes less and less as they become farther and farther away. If the pen and book were in deep space and right next to each other, they could attract one another more powerfully than any other object because of their relative mass/proximity ratio.

Answer 3

Still gravity just that it is so "teenie-tiny" (small) that you would have a very difficult time measuring it, so we use extrapolated math instead.