Natural log. Sorry about the math joke.
Because if they didn't they'd fall over.
Cher nob'll fall out.
Because he was barefooted!!!
Via the psycho path.
Hey baby, wanna see the exponential growth of my natural log?
A natural log.
Logic. (If you don't like physics jokes, just keep movin') ...(if you don't like math jokes, trust me, sometimes it makes a difference).