The smell of gravity is similar to the smell of death. Neither really have a distinct smell, unless you count rotting flesh as a smell of death, but we know these smells all too well. Gravity is more of a presence that we just accept, we don't comprehend it, but we don't question it, either. It's always there, whether it smells, or not. If you get gravity on you, it's hard to wash it off.
Gravity smells like fish.