"It's a custom on Earth," Ray says. "Stems from a time when men carried daggers and swords more than they do now. Most people on my planet use their right hands for nearly all their daily tasks, including fighting with weapons. They used to offer their right hands for the shaking as a way of showing that they weren't wielding a dagger and couldn't just stab you on the spot. You were supposed to shake their hand to show them that you weren't wielding anything either. We don't carry weapons like that as much any more, but we still do the hand thing anyway."