[Nick Danger]

gravity: my comment was about its generation.

It's a shame Einstein didn't live to see this riddle solved. I'm sure he'd have been amazed by your discovery.

[Lazamataz]

Gravity is generated by a large quantity of elves (called Gribbly Elves) who, using their cabbage fingers, clutch gently at anything made of rust, and pulls them gently towards them. The more mass, the more Gribblies, because Gribblies need to sit on something in order to grab something else.

Proof: