-- A phrase to explain one's klutziness in a non-offensive manner.
-- A method of distancing oneself from embarrassing actions such as dropping items, falling, spilling things, etc.
-- A way to divert the aggrieved party who has become soiled by your actions.
{At a bar}
Daphne: Thanks for spilling your wine all over me!
Jill: Sorry, hon. It was a gravity surge.
{Watching TV}
Bill: Yo, toss me the remote, bro.
(falls 5 feet short)
Fred: Sorry, dude. Gravity surge.