in a sense you are correct, this is pretty much what the super string theory is.

basically replace your iron bars with strings of gravity, and since ALL gravity effects ALL matter in the universe simultaneously, you could theoretically move a string and it will instantaneously move the part of the string billions of light years away.

at our current level of technology we dont have any way to manipulate gravity.

heres some more info on the theory, Superstring theory - Wikipedia, the free encyclopedia

i would also suggest reading "the elegant universe" but some chemistry and physics background will help alot

a theory about gravity, the one i choose to believe
"Gravity Dimension" - Gravity; faster than the speed of light!

hope this helps,
Raelum