A game of sorts...

"I'm certainly drilling no holes in my perfectly flat ceiling for you. Bowling balls are plastic. Perhaps a static charge has built up between them, pulling them closer to eachother. there are many other forces that pull objects together. not to mention all those 'experiments' I've seen at various "mystery spot" roadside attractions.

I've heard the moon argument before. I'm simply saying it's 'convenient' that the moon happens to "rotate" at the same rate it "orbits" at--since it's the most obvious evidence of a relatively close sphere-shaped object."

So let me get this straight, he gives you a perfectly good experiment to show that gravity exisits...and you tell him that you don't want to try it out because you might be proven wrong.  If there is a static charge built up, there certainly are many ways to remove it.  Your own denial to try experiments does NOT prove you right.

I hate to h8, but I don't think that bowling balls will pull together due to gravity in the manner you describe.  They are simply not massive enough to do it, when other influences are much stronger on them already.  The earth's gravity, for starters.  The sun, the moon, Jupiter, and heck probably most of the planets all have a stronger pull of gravity on the bowling balls than they will on each other.  Not to say I agree with reaperman (he's a complete idiot), but just saying I don't think that experiment is particularly valid.